# Stihl Carbon Fiber Fuel Injection



## RedneckChainsawRepair (Apr 30, 2014)




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## blsnelling (Apr 30, 2014)

Awesome! Wouldn't you love to work on that development team?!


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## XSKIER (Apr 30, 2014)

Quick! Sell all your M-Trons, 'cause they won't be worth squat when an EFI hits the market...


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## KenJax Tree (Apr 30, 2014)

Get ready to remortgage your house if you want one. 


Sent from my iPhone using Tapatalk


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## RedneckChainsawRepair (Apr 30, 2014)

You can see the carbon fiber parts better in this pic.


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## Grqnbech (Apr 30, 2014)

Wow I want one... Where do I sign up 

Sendt fra min Nexus 7 med Tapatalk


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## Chris-PA (Apr 30, 2014)

Ahh, marketing. 

What does the carbon fiber have to do with fuel injection? Maybe they need to offset the weight of the FI parts? You could make carbon fiber case parts any time, it's not high tech anymore. What advantage does FI have over a feedback carb, and how do they measure the fuel mixture? Measuring and controlling the fuel mixture is the same problem regardless of how you supply the fuel.


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## 7sleeper (Apr 30, 2014)

About time that they got their @$$ off the ground and started making a statement! The last decade was more than embarrising! In the vid down below the chief design engineer speaks about titanium muffler, carbon fiber components, aluminium screws and standard injection module like out of the cut off saws.

Here is a second vid.



7


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## bluesportster02 (Apr 30, 2014)

is the carbon fiber any lighter than the plastic it replaces. it looks great tho


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## XSKIER (Apr 30, 2014)

Great throttle response!


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## RedneckChainsawRepair (Apr 30, 2014)

*Page 1*
PRESS RELEASE
04/29/2014.
*I can not believe - not impossible, STIHL chainsaw Carbon Concept*
STIHL enlightens us by showing what could be possible in the future of high-quality
chainsaws product development.
Although STIHL chainsaw Carbon Concept hardly ever comes to production, so what looks like STIHL
is possible when the product development team responsible be given a free hand.
The result is a chain saw:
- Which is the world's most modern technology and the characteristics of
- With the world's best power-to-weight ratio of 1.11kg per kW (without guide bar and chain)
- Which is the lightest in its class thanks to the generous use of carbon fiber
- With the fuel injection on the first Chainsaw in the world
STIHL chainsaw Carbon Concept is not just meant for viewing, but it is also a job.
Feather-light weight it is easy to handle. Carbon Fiber 63cm long bar, weighing in at half a pound
less than a similar size to a normal bar. Carbon fiber is used in addition to the chain saw
other fine materials such as titanium and heat-insulating aluminum. Overall, the STIHL
Carbon Concept chainsaw weighs only 7.3kg and can be found in great power of 5.4kW (7.5hv). Such a power-
the weight ratio of the area has not ever been achieved.
Carbon Concept STIHL chainsaw is, therefore, a study from chain saws could be sometimes
in the future. The concept chain saw design and construction of the STIHL has been able to
learn things that should be taken into account, as well as introduce new products have been developing.
So we can stay with great interest to wait for the future and what kind of awesome high-tech products
STIHL's have up his sleeve.


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## RedneckChainsawRepair (Apr 30, 2014)




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## Plan-b (Apr 30, 2014)

bluesportster02 said:


> is the carbon fiber any lighter than the plastic it replaces. it looks great tho


 
haha. Not usually, but dont tell anyone.


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## farmer steve (Apr 30, 2014)

but.......does it come in orange?


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## Chris-PA (Apr 30, 2014)

JeremiahJohnson said:


> *Page 1*
> PRESS RELEASE
> 04/29/2014.
> *I can not believe - not impossible, STIHL chainsaw Carbon Concept*
> ...


1.11kg per kW @ 5.4kW = 5.99kg = 13.2lb.

7.3kg = 16.1lb

What is the displacement?


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## J.Walker (Apr 30, 2014)

JeremiahJohnson said:


> You can see the carbon fiber parts better in this pic.View attachment 347774



The first Stihl I really want!!


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## 7sleeper (Apr 30, 2014)

Chris-PA said:


> 1.11kg per kW @ 5.4kW = 5.99kg = 13.2lb.
> 
> 7.3kg = 16.1lb
> 
> What is the displacement?


The data was presented by _*keksfriedhof *_

Benzinmotorsäge STIHL Carbon Concept
Machbarkeitsstudie
Motor-Technologie: STIHL Injection
Hubraum (cm3): 82,4
Leistung (kW): 5,4
Gewicht (kg):* 6,0
Leistungsgewicht (kg/kW):* 1,11

erste voll funktionsfähige Motorsäge mit elektronisch gesteuerter
Einspritzung

Look here for the thread

http://forum.motorsaegen-portal.de/viewtopic.php?f=7&t=78628&p=1113841#p1113841

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## Wood Doctor (Apr 30, 2014)

Not sure why it won't go into production. If it does, I'll start salting away cash now for one of these puppies. The 460 looks close to this in size and costs $1,000 around here. Figure twice that for this saw if it were ever released?

Leave it to JJ to whet my appetite right before dinner.


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## sawfun (Apr 30, 2014)

I hope this helps their balance since that is a big advantage their main.competitor seems to have down well.


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## blsnelling (Apr 30, 2014)

sawfun said:


> I hope this helps their balance since that is a *perceived* advantage *SawTroll* seems to have down well.


 Fixed for truth


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## RedneckChainsawRepair (Apr 30, 2014)

Remember DC Hotsaws 2012 . Stihl has a lot of catching up to do. 

Banner I used on the chainsaw repair site 2012


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## hamish (Apr 30, 2014)

Cant wait to see the added cost to shed a mere pound off of a 7hp saw.


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## RedneckChainsawRepair (Apr 30, 2014)

Screw the weight thing. I want to see that fuel injection.


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## redfin (Apr 30, 2014)

blsnelling said:


> Fixed for truth



I don't hit the like button often but when I do.......


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## redfin (Apr 30, 2014)

JeremiahJohnson said:


> Screw the weight thing. I want to see that fuel injection.


Yup!


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## VinceGU05 (Apr 30, 2014)

hamish said:


> Cant wait to see the added cost to shed a mere pound off of a 7hp saw.


1.4 kg lighter. thats about 3lb.

http://www.stihl.com/stihl-carbon-concept-chain-saw.aspx

http://www.stihl.com/pi-stihl-continues-to-grow-and-presents-world-firsts.aspx


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## Chris-PA (Apr 30, 2014)

Let's see if anyone can name a single advantage of fuel injection into the case of a single cylinder 2-stroke chainsaw engine.


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## Plan-b (Apr 30, 2014)

Chris-PA said:


> Let's see if anyone can name a single advantage of fuel injection into the case of a single cylinder 2-stroke chainsaw engine.


 
Easy cold start.


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## VinceGU05 (Apr 30, 2014)

The remarkable power for the STIHL Carbon Concept chain saw's low weight of 7.5 HP (5.4 kW) is produced by an internal combustion engine with electronic fuel injection, the STIHL Injection. That's another first in chain saw technology. The STIHL Carbon Concept thus produces optimum engine power in all operating states and high torque combined with excellent running behavior and acceleration.

just like it would in a 4 stroke engine. cost is the main problem i would think.


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## Knobby57 (Apr 30, 2014)

Chris-PA said:


> Let's see if anyone can name a single advantage of fuel injection into the case of a single cylinder 2-stroke chainsaw engine.


I assume that your kidding?


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## hamish (Apr 30, 2014)

VinceGU05 said:


> 1.4 kg lighter. thats about 3lb.
> 
> http://www.stihl.com/stihl-carbon-concept-chain-saw.aspx
> 
> http://www.stihl.com/pi-stihl-continues-to-grow-and-presents-world-firsts.aspx



If the operating weight is 7.3kg then yes. PHO would be about 4lbs lighter than the 395.


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## Deets066 (Apr 30, 2014)

I want one! I've had a bad case of cad lately and this sure ain't helpin


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## STIHLTHEDEERE (Apr 30, 2014)

I am sure they stole this idea, or purchased the technology from husky............................


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## Chris-PA (Apr 30, 2014)

Plan-b said:


> Easy cold start.


That _might_ be one, if they can store pressure for a long time.



Knobby57 said:


> I assume that your kidding?


Not at all - what advantages do you see? 

Remember, they are injecting the fuel into the case, not the cylinder. It's a single cylinder so there are no fuel distribution issues. Carbs can vaporize fuel very well, and it's going into the case anyway. 

Just like with a feedback carb, you need some means of measuring the mixture and then a microcontroller based circuit to adjust it. Unless you are going to add a bunch of extra sensors (which the Stihl system does not have), you'll end up doing something like the lean-out/rpm test used on AT/MT so the mixture won't be any more accurate. The difference is only in the fuel output device - and a carb is much simpler, cheaper and probably lighter.


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## jughead500 (Apr 30, 2014)

Naw stihl made it.husky will perfect it.lol
Yeap I'd like to see the fuel injection too.then modify it to put on my pm700.


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## STIHLTHEDEERE (Apr 30, 2014)

Chris-PA said:


> Let's see if anyone can name a single advantage of fuel injection into the case of a single cylinder 2-stroke chainsaw engine.


 easier to start in the cold, exceptionally longer engine life, fuel economy, power, less emissions, no carb to mess with........................thats 6 oh yeh and another thing, stihl has it and husky does not.


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## STIHLTHEDEERE (Apr 30, 2014)

Chris-PA said:


> That _might_ be one, if they can store pressure for a long time.
> 
> 
> Not at all - what advantages do you see?
> ...


 have you looked a ts500i over? they are pretty darn simple for what they are


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## banana boat (Apr 30, 2014)




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## Chris-PA (Apr 30, 2014)

STIHLTHEDEERE said:


> exceptionally longer engine life, fuel economy, power, less emissions


Go ahead, explain how those 4 would work.


STIHLTHEDEERE said:


> have you looked a ts500i over? they are pretty darn simple for what they are


I watched their promo video and it looked considerably more complex than AT/MT - as it must be given the fuel pressure requirement. For what advantage? _Possibly_ faster cold start?


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## chadihman (Apr 30, 2014)

JeremiahJohnson said:


>



I'll own the first one that arrives at the dealership I work at.


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## bert the turtle (Apr 30, 2014)

Won't go into volume production. I'd be happy to buy one as a limited edition.


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## chadihman (Apr 30, 2014)

jughead500 said:


> Naw stihl made it.husky will perfect it.lol
> Yeap I'd like to see the fuel injection too.then modify it to put on my pm700.


Naw Husky wont be able to keep there injector hold down bolts in place. lol


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## redfin (Apr 30, 2014)

STIHLTHEDEERE said:


> exceptionally longer engine life



Why do you think this?


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## Chris-PA (Apr 30, 2014)

If they made a carbon fiber 291 would it be a pro saw then?


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## sawfun (Apr 30, 2014)

Why wouldnt you use a nozzle to direct most of the fuel into the cylinder, whether one OR multi, at the proper time. Its been a proven system for a while now. Some dirt bikes now have it and they are one cylinder. Use a smaller percent to lube and cool the engine in the conventional two stroke manner. Thats the way a modern supercharged four stroke runs nobody thought that was necessary in the past. Turns out it kinda helped out a lot. Ethanol could be less of a problem, which is probably just one factor.


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## Knobby57 (Apr 30, 2014)

Chris-PA said:


> That _might_ be one, if they can store pressure for a long time.
> 
> 
> Not at all - what advantages do you see?
> ...



It would not need to store pressure over time. If it has a pump driven off the crank the minimal capacity of the system would pressurize almost instantly , it would be very simple to use a oversize pump with a pressure relief to accomplish this .
As for a carb ..... Probably with most problematic part of any saw. A pump driven off the crank with Mechanical injection system with flow adjusted the same way as the cm carbs , it would eliminate the rubber fuel lines , rubber impulse line, finacky car internals , and eliminate the need for winter and summer mode to keep the carb warm in the cold. A tipical chainsaw car has a high and low circut . Even a low tech injection system is self ajustabale more quickly than a carb as it would not have to depleat the fuel already in the carb circuit past the adjustment needle before the adjustment takes effect. Having just a throttle body where a carb would be you are not limited by venturi size( by nature works best at a specific CFM). With a larger throtal body it would be like have a much larger carb but not have the bogging and poor low end and loss of torque . All of this can be easily accomplished with no more electronics than what we already have on some saws. Throw a crank position sensor in the mix and the possibilities are endless .
It would not be very hard to build a fuel pump asy. Driven off the crank with a integrated fuel injector. So as for added parts and weight it's probably a wash. A carb is antiquated tech but they are inexpensive and for the most part most people are not very accepting to change and new fangled things . I would bet if stihl did a statistic sales and necessity demographic study this would be a flop present day.


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## Terry Syd (Apr 30, 2014)

If they are serious about making a chainsaw lighter, then they can start by putting aluminium screws in the saws. Since when do you need steel screws to torque down in PLASTIC components.

There are plenty of manufacturers of aircraft quality screws, nuts and bolts - the parts have been available for years, so why haven't they been used?


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## Big_Wood (Apr 30, 2014)

i never thought i'd say this but i want one. until husky releases their competitor model of coarse  finally something that stihl thought up on their own  i am very interested. to bad they aren't available right now cause i got some money burning a hole in my pocket.


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## hamish (Apr 30, 2014)

STIHLTHEDEERE said:


> have you looked a ts500i over? they are pretty darn simple for what they are


And still computer controlled, just a different take on the fuel valve placement/means of delivery.


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## sawfun (Apr 30, 2014)

I am not a big fan of electronics either, but its hard to argue with their success.


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## MustangMike (Apr 30, 2014)

Carbon is both lighter and stronger than plastic, and you can design it to flex one way but not another (which could help with AV). Virtually all of the high end bikes (w/peddles) are made of carbon. They are very stiff is some directions (to put your power to the ground) but compliant in other directions (to provide a smooth ride and better road contact). Some of them are also so light that they must add weight to be legal in the Tour De France.

I just hope the new saws don't cost as much as my bike!


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## PES+ (Apr 30, 2014)

Chrisinjector PA said:


> Let's see if anyone can name a single advantage of fuel injection into the case of a single cylinder 2-stroke chainsaw engine.


This type of injector is impervious to fuel type and quality.

there are zero carbs that are even close

And they better be using only their fi stuff and not stuff that I and a couple of other guys were working on.....


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## PES+ (Apr 30, 2014)

If it is "complex" they are doing it the stupid chinese scooter set up way and that set up is a PITA and not at all bullet proof.

I will let them waste millions cause they never listen to me......the 4 mix was dumb as hell but they built it anyway......lol

I sure s hell wont sell it to HUSKY


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## MustangMike (Apr 30, 2014)

Carbon can take a lot of weight off, you can even use a carbon connecting rod.

And direct fuel injection would allow for higher compression w/o pre-detonation.


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## PES+ (Apr 30, 2014)

Titanium a better choice for rods cf flexs too much


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## MustangMike (Apr 30, 2014)

I think it depends on the grade of carbon and how they layer it up. The Titanium bikes were a big thing for a while, but all replaced by Carbon! They even sometimes use carbon crank arms on the bikes (a piece that must be very rigid). Ditto handlebars and stems, If titanium were as light and strong, that is what they would use. All of the bikes that I know of that cost over $10,000 have carbon handlebars, and pro riders do not want them to flex (they would loose power transfer to the ground).


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## PES+ (May 1, 2014)

It works or lots of things but connetings rods nt so much....there are better solid synthetics but they have other issues with heat and fuel tolerence.
Take a cf tube or even soid bar and flex it with both hands and see what i mean.

Cabon handlebars flex quite a bit but this is a good thing for damping vibration and it keeps your arms from pumping up and keeps your hands from tingling.

Cf became a WAY overrated material and ended up in all kinds of inappropritate applications.


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## sawfun (May 1, 2014)

Top fuel had carbon fiber valve covers for a while but now use titanium so yes, cf. does have limitations or more likely, prefered applications. Ti rods have been used for a while now. There have been ti valve springs for years. Unfortunately, lifespan is very short.


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## PES+ (May 1, 2014)

There again it is not for every purpose either....it makes terrible springs


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## dl5205 (May 1, 2014)

I've long had an interest in a 'weight weenie' carbon/ ti/ drillium/ 'weight tuned' saw.

I think it's a very neat 'concept saw' that will almost definitely never see production.


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## KG441c (May 1, 2014)

MustangMike said:


> I think it depends on the grade of carbon and how they layer it up. The Titanium bikes were a big thing for a while, but all replaced by Carbon! They even sometimes use carbon crank arms on the bikes (a piece that must be very rigid). Ditto handlebars and stems, If titanium were as light and strong, that is what they would use. All of the bikes that I know of that cost over $10,000 have carbon handlebars, and pro riders do not want them to flex (they would loose power transfer to the ground).


Mustang I can relate to the cf in the road bikes as I recently sold my one of many bikes some carbon and some aluminum. My last bike was an aluminum caad 10 frame with everything else on it being carbon except the frame. The whole bike was 16.8 lbs. But from my experience with road biking and dirtbike racing which also used alota carbon is that if crashed and a hairline cracked developed it usually turned catastrophic. cf is very strong but once stressed and fails its a done deal. A crash with an aluminum bike was much more forgiving on the frame!!


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## PES+ (May 1, 2014)

And cf binder adhesives are difficult with modern gasolines and nitromethane is right out.....

you can resist petroleum and you can resist alcohols but you can' do both and deal with the acids and aldehydes that are inside all engines


dl5205 said:


> I've long had an interest in a 'weight weenie' carbon/ ti/ drillium/ 'weight tuned' saw.
> 
> I think it's a very neat 'concept saw' that will almost definitely never see production.


Agree.....rather like a pen that writes under whipped cream....grin


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## Matt B (May 1, 2014)

We use a lot of CF in our windsurfing gear. The increased strength of the fibre allows for much less resin to be used compared to other plastic/fibre combinations, hence the weight savings. Also the supporting structure eg the foam of a board, can now be of lower density and strength.

The reason I bought this up in a saw forum is that windsurfing gear, like saws, gets knocked about.

Point source loads perpendicular to a CF surface have seen the end of lots of $1000+ masts. Watch the face of a sailor who drops a mast on some rocks. He knows that the mast may now be compromised and snap at any moment when put under load.

As indicated by others here CF has it's adantages but in our experience it has to be treated with care. Admittedly it looks like most of the carbon components in stihl's new toy aren't bearing high loads. Although keeping the CF bonded to the metallic components in a bar which is constantly flexing and coming under load would be a challenge...


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## KG441c (May 1, 2014)

But carbon can be used in a gasoline engine ? Isnt Dolmar using carbon fiber intake reeds in the 6100?


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## PES+ (May 1, 2014)

Yes but the will have issues with the new american crap they call "gasoline"


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## PES+ (May 1, 2014)

Losing a reed is not a big deal....losing a rod is a VERY big deal...


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## KG441c (May 1, 2014)

Im all familiar with carbon with the weight savings in road bikes and dirtbikes and even Boyeson Power Reeds in 2 stroke outboards , but from my experience Id be reluctant in using for connecting rods and internals with combustion and heat?


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## PES+ (May 1, 2014)

It is the whipping and twisting that makes it useless for high load hiph speed use in this application


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## STIHLTHEDEERE (May 1, 2014)

Chris-PA said:


> Go ahead, explain how those 4 would work.
> 
> I watched their promo video and it looked considerably more complex than AT/MT - as it must be given the fuel pressure requirement. For what advantage? _Possibly_ faster cold start?


 are you kidding? you must be a little on the ......................slow side? do you have any common sense? how many cars/trucks/motorcycles do you see without F/I? we are no longer in 1977, all small engines will go to this sooner or later.


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## Chris-PA (May 1, 2014)

STIHLTHEDEERE said:


> are you kidding? you must be a little on the ......................slow side? do you have any common sense? how many cars/trucks/motorcycles do you see without F/I? we are no longer in 1977, all small engines will go to this sooner or later.


Just as I thought - they got you with the buzzword: Fuel injection = Good. I'm not so slow as to be taken in by the marketing man with a little bit of shiny gee-wiz tech-looking stuff. 

Look at the actual system and how it works, and see if any of those things that are advantages in other machines are here, and if the system works the same. I've been playing around with fuel injection for some time, even back with those horrid Bosch CIS systems. 

..................

Guys, it's a cool saw, just like the stuff they show at car shows. Sometimes those give hints at what is coming and sometimes they're just fluff. Both carbon fiber and this FI system have been around a while but are not being used on saws. That's probably because carbon fiber is too expensive and offers too few advantages. And Stihl keeps putting M-tronic on their saws - wonder why? Because there aren't enough advantages to justify the cost.

Look at the materials used on a modern high end chainsaw - see any particularly exotic materials? They're pretty simple machines made out of rather basic materials. Can you imagine what they'd cost otherwise?

Probably the most interesting thing here is the bar.


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## 7sleeper (May 1, 2014)

@Chris-PA 

I see it a little bit different. The majic word I hear buzzing is planned obselesence. If you build a saw like that, it will last forever! Very bad for business! 

7


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## gunnusmc03 (May 1, 2014)

Chris-PA said:


> Just as I thought - they got you with the buzzword: Fuel injection = Good. I'm not so slow as to be taken in by the marketing man with a little bit of shiny gee-wiz tech-looking stuff.
> 
> Look at the actual system and how it works, and see if any of those things that are advantages in other machines are here, and if the system works the same. I've been playing around with fuel injection for some time, even back with those horrid Bosch CIS systems.
> 
> ...


You missed the whole point of FI saws, that saw is 82cc and due to the fuel injection makes the same power as the 91 cc 661. There's other benefits also such as easier to start and increased throttle response.


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## banana boat (May 1, 2014)

sawfun said:


> Top fuel had carbon fiber valve covers for a while but now use titanium so yes, cf. does have limitations or more likely, prefered applications. Ti rods have been used for a while now. There have been ti valve springs for years. Unfortunately, lifespan is very short.




Why would they use titainum valve covers when aluminum is lighter? and titanium valve springs last way longer than steel.


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## MustangMike (May 1, 2014)

Every material has advantages & disadvantages, but to imply that professional bike riders in the Tour etc are not using the best material available for the application is ludicrous. These guys care far more about performance than comfort, and 1/10s of a second are a huge deal to them. If any material will help to propel a rider across the finish line first, the bike company will be using that material, and there is nothing they have not tested. Some of the carbon they use is such high military grade that they are not allowed to export it except as a finished product.


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## sawfun (May 1, 2014)

Titanium takes to being installed and removed often much better than c.f. does. Also if something goes bang its stronger to contain flying parts.


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## PES+ (May 1, 2014)

bananaoat said:


> Why would they use titainum valve covers when aluminum is lighter? and titanium valve springs last way longer than steel.


You sir are an xxxx.......sigh


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## Knobby57 (May 1, 2014)

PES+ said:


> You sir are an diot.......sigh


+1 don't even know what to say about this 


Sent from my iPhone using Tapatalk


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## KG441c (May 1, 2014)

MustangMike said:


> Every material has advantages & disadvantages, but to imply that professional bike riders in the Tour etc are not using the best material available for the application is ludicrous. These guys care far more about performance than comfort, and 1/10s of a second are a huge deal tthem. If any material will help to propel a rider across the finish line first, the bike company will be using that material, and there is nothing they have not tested. Some of the carbon they use is such high military grade that they are not allowed to export it except as a finished product.


True but Ive had Trek Madone carbon 6 series which is a 7000$ Bike and a Cannondale Caad 10 aluminum bike. Trek madone 20lbs, caad 10 was 16.8lbs. The caad 10 was much softer ride, more responsive and and way more durable. I know weight is most important to touring riders but dont underestimate what they r doing with aluminum, geometry of tubes and the effiency of the aluminum now as they r coming close to carbon bikes now but carbon is the best choice right now but IMO CF will have no place internally in chainsaws! Sure externally for weight savings but all this is just my opinion and past experiences with CF


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## dl5205 (May 1, 2014)

PES+ said:


> Agree.....rather like a pen that writes under whipped cream....grin



Well, one Could find oneself in the desert, where it would be impractical to write underwater...


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## Chris-PA (May 1, 2014)

gunnusmc03 said:


> You missed the whole point of FI saws, that saw is 82cc and _*due to the fuel injection makes the same power as the 91 cc 661*_. There's other benefits also such as easier to start and increased throttle response.


Specifically, how do you believe fuel injection accomplishes this all by itself? What different thing happens when you squirt fuel into the case vs. drawing air through a carb and letting it pick up the fuel that causes this higher power output (assuming both have a feedback system to maintain the correct fuel/air ratio)?


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## banana boat (May 1, 2014)

PES+ said:


> You sir are an diot.......sigh





Knobby57 said:


> +1 don't even know what to say about this
> 
> 
> Sent from my iPhone using Tapatalk




Excuse me?

Here is a quote from a manufacturer who makes titanium springs for top fuel dragsters

http://www.rentoncoilspring.com/performance/auto_racing/
"The titanium valve springs are also a better value. Although they cost more than the steel valve springs they will last 5 to 7 times longer. The steel springs will begin to take set during the burnout. Whereas the RCS titanium springs will last between 10 and 20 runs.

And aluminum is lighter than titanium....weaker but lighter. so being a valve cover and not a critical engine part my question was valid.

http://www.titaniumdistributor.com/all-about-titanium.htmlTitanium is 30% stronger than steel, but is nearly 50% lighter. Titanium is 60% heavier than aluminum, but twice as strong

So how am I an idiot? Please do explain, and no I'm not a top fuel expert and never claimed to be, heck I hardly know anything about them except they are awesome  but no matter what they use for valve spring and cover materials I don't feel like my questions somehow make me an idiot especially since titanium does make an excellent spring and aluminum size for size is actually a lot lighter than titanium.


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## sawfun (May 1, 2014)

I dont know the manufacturer you speak of and its been 10 years so maybe they have improved things or changed alloys but those springs lasted two maybe if you pushed it three runs and they were run on alcohol cars that had high boost rates. The fuel cars ran regular springs as they dont develop the boost of an alcohol car and dont run near the rpm. I know because I had a fuel roadster and crewed on an alcohol funny car for a few years.


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## Knobby57 (May 1, 2014)

Chris-PA said:


> Specifically, how do you believe fuel injection accomplishes this all by itself? What different thing happens when you squirt fuel into the case vs. drawing air through a carb and letting it pick up the fuel that causes this higher power output (assuming both have a feedback system to maintain the correct fuel/air ratio)?


I believe I covered part of this earlier on this topic . I can write a book on how it's better and get into thermal dynamics , are velocity and cavitation,atomization , and fluid dynamics . Easily put it's better in every way except for cost of production . If you fail to see this I suggest first you take a look around and see what every other motor with clean emissions and great drivability uses and then take some engineering classes . If you still don't understand go back to playing with playdoe and watching cartoons because there is no hope for you 


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## dl5205 (May 1, 2014)

Knobby57 said:


> ... take some engineering classes ....



While I'm neither for nor against FI on chainsaws, that's rather humorous.


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## Knobby57 (May 1, 2014)

dl5205 said:


> While I'm neither for or against FI on chainsaws, that's rather humorous.


Don't get me wrong you can get it done with a carb. I'm very happy with my saws but I'm sure a well put together FI model would be leaps and bounds better 


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## dl5205 (May 1, 2014)

I was referring to your questioning of ChrisPA's level of education.


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## jdhacker (May 1, 2014)

We go from a prototype chainsaw, to top fuel cars in one thread got to love it.


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## PES+ (May 1, 2014)

Those are not titanium springs...read your own linked material....you are mixing things up like people used to do with GB bars...why were those bars so heavy?


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## banana boat (May 1, 2014)

PES+ said:


> Those are not titanium springs...read your own linked material....you are mixing things up like people used to do with GB bars...why were those bars so heavy?



I did read it, let me copy and paste it for you and make it easier for you to read.

"RCS manufactures a *Titanium valve spring* for Pro Stock, Top Fuel, and Alcohol drag race engines"

"The *Titanium valve springs* are also a better value. Although they cost more than the steel valve springs they will last 5 to 7 times longer "


"Ti valve springs for pro stock drag racing: *Titanium springs* are run 5-8 times as many times down the track. A set of steel springs cost $400 and a titanium set costs $1750. The per-use cost of Steel is $400. The per use cost of titanium is $1750/5 = $350. In addition time and labor is saved as the springs do not need to be changed in between each race. Titanium springs deliver higher performance (stable at higher RPM) for slightly less cost."


"RCS *titanium valve springs* are the standard of the industry to which all titanium springs are measured. The have helped us and our customers win championships for a decade. They are simply the best.

Alan Johnson, Owner and Crew Chief, 3 Time NHRA Top Fuel Champion."



All takin directly from the site I linked, I'm done talking with you, back to chainsaws


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## Hinerman (May 1, 2014)

KG441c said:


> True but Ive had Trek Madone carbon 6 series which is a 7000$ Bike and a Cannondale Caad 10 aluminum bike. Trek madone 20lbs, caad 10 was 16.8lbs.


 
HA, I would have to loose about 50-60 lbs before I would consider spending $7k to loose 3.2 lbs on a bike. You must be a serious rider...

I, for one, am looking forward to fuel injected saws...


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## Knobby57 (May 1, 2014)

Hinerman said:


> HA, I would have to loose about 50-60 lbs before I would consider spending $7k to loose 3.2 lbs on a bike. You must be a serious rider...
> 
> I, for one, am looking forward to fuel injected saws...


I used to do a lot of track days on motorcycles till I darn near ripped my leg off. My buddy would spend crazy money to shave ounces off his bike I would tell him I just won't eat breakfast before a race lol. He weights in around 375 I'm 175 and with more hp I never did ever catch him 


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## Chris-PA (May 1, 2014)

Knobby57 said:


> It would not need to store pressure over time. If it has a pump driven off the crank the minimal capacity of the system would pressurize almost instantly , it would be very simple to use a oversize pump with a pressure relief to accomplish this .
> As for a carb ..... Probably with most problematic part of any saw. A pump driven off the crank with Mechanical injection system with flow adjusted the same way as the cm carbs , it would eliminate the rubber fuel lines , rubber impulse line, finacky car internals , and eliminate the need for winter and summer mode to keep the carb warm in the cold. A tipical chainsaw car has a high and low circut . Even a low tech injection system is self ajustabale more quickly than a carb as it would not have to depleat the fuel already in the carb circuit past the adjustment needle before the adjustment takes effect. Having just a throttle body where a carb would be you are not limited by venturi size( by nature works best at a specific CFM). With a larger throtal body it would be like have a much larger carb but not have the bogging and poor low end and loss of torque . All of this can be easily accomplished with no more electronics than what we already have on some saws. Throw a crank position sensor in the mix and the possibilities are endless .
> It would not be very hard to build a fuel pump asy. Driven off the crank with a integrated fuel injector. So as for added parts and weight it's probably a wash. A carb is antiquated tech but they are inexpensive and for the most part most people are not very accepting to change and new fangled things . I would bet if stihl did a statistic sales and necessity demographic study this would be a flop present day.





Knobby57 said:


> I believe I covered part of this earlier on this topic . I can write a book on how it's better and get into thermal dynamics , are velocity and cavitation,atomization , and fluid dynamics . Easily put it's better in every way except for cost of production . If you fail to see this I suggest first you take a look around and see what every other motor with clean emissions and great drivability uses and then take some engineering classes . If you still don't understand go back to playing with playdoe and watching cartoons because there is no hope for you


Man, you get nasty quick. 

I didn't respond to your first comment because it was so full of inaccuracies. You clearly have no understanding of how a carburetor works. These all-position carbs are terribly inaccurate in terms of mixture control with variation in air velocity, but they don't have to be - it's only because they removed the air correction jets that are used to linearize the response. Properly set up even a non-feedback carb is a passive device that automatically provides the correct mixture over a wide range of air velocities, and this can (and is) extended by the addition of separate low speed circuits, as well as an accelerator pump to accommodate variable speeds. A properly set up carb provides nearly instantaneous throttle response and very good fuel atomization. If you add a feedback system it can compensate for mixture errors with a fairly slow response time, and does not have to provide pulse-by-pulse active control. 

By contrast a fuel injection system is an active device that must always be controlled by some mechanical or electronic system. It can only be as accurate as its sensing and control system, and here they have case pressure, temperature, crank position and rpm. That is inherently more than a carb needs, because a carb can provide an essentially correct mixture based on the physical properties of the venturi while an FI system cannot. Some early mechanical systems used an air vane in the intake path running a valve to essentially mimic what a carb does. There's nothing to directly measure exhaust oxygen, so they'll have to do something like a lean-out test just like with MT/AT. 

You babble on about crank driven fuel pumps (which this system does not have), and throw in terms like "thermal dynamics, are velocity and cavitation, atomization, and fluid dynamics" without a shred of explanation as how they are relevant. Sorry, not impressed. Maybe you should actually look into the system you are discussing before you spout off. 

-------------

There actually is one possible advantage, which no one picked up on - that would be if you can time the fuel pulse accurately enough to control when the fuel enters the combustion chamber. Then you could effectively do strato without the extra porting. At 10,000rpm the entire cycle is about 6ms. To time it you'd have to hit a window of maybe 30deg, which is 0.5ms. Beyond that, the injector is in the front of the case, and the fuel pulse has to get past the spinning crank and reciprocating parts, up the transfers and still be a controlled and reasonably defined fuel pulse. It would be quite a challenge. 

Yet they still build strato engines with feedback carbs, which tells me that even if this system works any better the cost is too high for any advantage it may have.


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## Knobby57 (May 1, 2014)

Sorry for coming across as Nasty . You are missing the point , and extremely misinformed , I could explain things further but you do not understand the simple parts so it's fruitless and a waste of time. I could easily design a FI system for a saw that works fantastic without anything more than a temp for input . It's all in the programming and fuel maps , I have absolutely no experience in building fuel maps so I could not begin to tell you how it's done . But I can tell you it's entirely possible . Will it be cost effective . More than likely no. I'm sure they guys at stihl built theirs the way they did for a reason your guess is as good as anyone's . Also it's entirely possible to build one system that will fit most saws with a different CPU to control it. If you want to take a couple months to understand what I was talking about with the Venturi being fixed for one cfm flow . And understand dynamics I got free time at night . Took me 6 years to learn the basics and I'm relatively uneducated compared to a few on my friends who could melt your brain with this crap . 


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## Knobby57 (May 1, 2014)

Also if the fuel pump is not driven somehow off the crank how are they going to build fuel pressure . I'm sure there is no battery , charging system , or electric fuel pump. So aside from magic or pixie dust I would assume it's driven off the crank 


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## Knobby57 (May 1, 2014)

Also you asked how if would be better . You did not specify the particular FI that is said to be on this saw. I take vids like these with a grain of salt. May just be marketing bs. But I and still holding too it's very very possible to make a FI system on a single cylinder 2 stoke work well better than a carb. Probably all a moot point as with increasing emission regulations sooner or later you will see 4 stroke chainsaws hitting the market 


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## Chris-PA (May 1, 2014)

Knobby57 said:


> Sorry for coming across as Nasty . You are missing the point , and extremely misinformed , I could explain things further but you do not understand the simple parts so it's fruitless and a waste of time. I could easily design a FI system for a saw that works fantastic without anything more than a temp for input . It's all in the programming and fuel maps , I have absolutely no experience in building fuel maps so I could not begin to tell you how it's done . But I can tell you it's entirely possible . Will it be cost effective . More than likely no. I'm sure they guys at stihl built theirs the way they did for a reason your guess is as good as anyone's . Also it's entirely possible to build one system that will fit most saws with a different CPU to control it. If you want to take a couple months to understand what I was talking about with the Venturi being fixed for one cfm flow . And understand dynamics I got free time at night . Took me 6 years to learn the basics and I'm relatively uneducated compared to a few on my friends who could melt your brain with this crap .


Sad that you can't stop being insulting even after apologizing for it. I understand venturis fairly well. 

The fuel map of an injection system is just the basic relationship of fuel output for a given set of inputs - whatever it's been programmed to do based on the inputs the system may have. Here they have case pressure, temperature, crank position and rpm - that will get them fairly close, which is good enough. Rpm and case pressure are probably the main inputs they're looking at - they can probably get a fairly good idea of the load and intake air volume from that.

This is just analogous to the behavior of a carb, where the fuel output is a function of various physical properties but primarily air velocity through a venturi and fuel flow through the jet. The jets and the venturis may be either fixed or variable, there are lots of designs out there. 

If you are focused on fuel maps you've missed the concept of how these system work, as the fuel map is irrelevant once the system is running in closed loop mode. Then the mixture is controlled by looking at the primary feedback system (i.e. lean-out test or some equivalent). Just as the native fuel delivery characteristics of the carb are irrelevant once the feedback system is actively controlling the mixture. 



Knobby57 said:


> Also if the fuel pump is not driven somehow off the crank how are they going to build fuel pressure . I'm sure there is no battery , charging system , or electric fuel pump. So aside from magic or pixie dust I would assume it's driven off the crank


It does not appear to be driven off the crank, probably a pulse pump driven off crankcase pressure pulses. Watch the video: 
Remember, it has to compete with a cheap piece of cast pot metal with a couple of holes drilled in it.


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## Knobby57 (May 1, 2014)

Also you asked how if would be better . You did not specify the particular FI that is said to be on this saw. I take vids like these with a grain of salt. May just be marketing bs. But I and still holding too it's very very possible to make a FI system on a single cylinder 2 stoke work well better than a carb. Probably all a moot point as with increasing emission regulations sooner or later you will see 4 stroke chainsaws hitting the market 


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## Knobby57 (May 1, 2014)

Chris-PA said:


> Sad that you can't stop being insulting even after apologizing for it. I understand venturis fairly well.
> 
> The fuel map of an injection system is just the basic relationship of fuel output for a given set of inputs - whatever it's been programmed to do based on the inputs the system may have. Here they have case pressure, temperature, crank position and rpm - that will get them fairly close, which is good enough. Rpm and case pressure are probably the main inputs they're looking at - they can probably get a fairly good idea of the load and intake air volume from that.
> 
> ...



There is no closed loop mode if you do not have external exhaust gas input . You can believe what you want but you are misinformed . You asked about if I general . Apples and oranges , you can't be throwing your oranges at my apple explanation. And by the way I am incredibly informed how a carb works and even more on how if works in various forms . There is more than one way to skin a cat . Don't be too closed minded to see it . If you don't want a answer don't ask a question . I've said it before a little bit of knowledge for some people is worse than being ignorant . I'm finished with this . Spew away all the misguided info you have. Most on here are pretty slick and will know to just ignore you miss informed incorrect posts 


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## Chris-PA (May 1, 2014)

Knobby57 said:


> _*There is no closed loop mode if you do not have external exhaust gas input .*_ You can believe what you want but you are misinformed . You asked about if I general . Apples and oranges , you can't be throwing your oranges at my apple explanation. And by the way I am incredibly informed how a carb works and even more on how if works in various forms . There is more than one way to skin a cat . Don't be too closed minded to see it . If you don't want a answer don't ask a question . I've said it before a little bit of knowledge for some people is worse than being ignorant . I'm finished with this . Spew away all the misguided info you have. Most on here are pretty slick and will know to just ignore you miss informed incorrect posts


And you keep calling me misinformed? Do some research on how AutoTune and M-tronic work - they are closed loop systems. This conversation was about Stihl's FI system, which is an existing design, not some dream system you made up.


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## PES+ (May 1, 2014)

Tell me why the titanium valve spring on my tool box is hanging from a magnet.....my god...brain death is awful...really


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## PES+ (May 1, 2014)

You really need to do stuff instead of surfing the internet....god


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## Knobby57 (May 1, 2014)

PES+ said:


> Tell me why the titanium valve spring on my tool box is hanging from a magnet.....my god...brain death is awful...really


Hahaha


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## Knobby57 (May 1, 2014)

Chris-PA said:


> And you keep calling me misinformed? Do some research on how AutoTune and M-tronic work - they are closed loop systems. This conversation was about Stihl's FI system, which is an existing design, not some dream system you made up.


 This reminds me of a great quote . " never argue with a idiot , they will bring you down to there level and beat you with experience " red green . You asked a generalized question . I gave you you a very informed answer . Do with it what you wish . It seams this is twice now I've got in a conversation like this on this site with the same results . The other changing the dynamic ( just to throw that word in again) of the question to there liking when thought needed by them to make a point . Like I said get some knowledge and come see me. No the first thing that pops up on a google search like the last disagreement I had on here. Bonjour !! I'm a French model!! 


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## Marshy (May 1, 2014)

So much fun here, unfortunately I dont have the time to finish reading page 5 and 6 but still wanted to make a few comments. I will come back and read the rest later.



PES+ said:


> You sir are an diot.......sigh


Lol the kettle calling the pot black. 



Chris-PA said:


> Specifically, how do you believe fuel injection accomplishes this all by itself? What different thing happens when you squirt fuel into the case vs. drawing air through a carb and letting it pick up the fuel that causes this higher power output (assuming both have a feedback system to maintain the correct fuel/air ratio)?


 
As a whole it is complicated and I can think of a few advantages FI creates but only have time for a couple. For one, fuel atomization from the FI is WAY superior than carbs. One of the advantage this creates is lower combustion charge temperature and a better flame front during combustion. This also corrolates to more efficient burn of the fuel and more power gained.


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## MustangMike (May 1, 2014)

KG, I won't disagree with you about carbon inside the engine, I simply don't know, but how did you get a Madone 6 so heavy???? I've got a Madone 7 60 cm frame and w/o pedals it is under 16 lbs. Heck even my 08 5 series was under 20 lbs. I have also never heard anyone say their metal bike provided a softer ride than carbon, and everyone I ride with has gone from metal to carbon. If the seat and tires are the same, metal simply does not have the ability to flex in one direction but not the other the way carbon does. Regarding durability, my 08 Madone saw 4,000 miles a year for 5 years w/o any frame problems (I bent an aluminum wheel on a squirrel), but ditto the carbon wheels, no problems.

Is your bike 100% aluminum, or does it use carbon joints? And fork?

However, I did go for Aluminum with the Mtn bike due to fear of impact.

It takes more force to damage carbon than metal, but once it goes it goes.


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## andydodgegeek (May 1, 2014)

This thread started kind of interesting but it sure is lame now. Happens a lot around here. It's just a chainsaw!!!


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## Chris-PA (May 1, 2014)

Knobby57 said:


> This reminds me of a great quote . " never argue with a idiot , they will bring you down to there level and beat you with experience " red green . You asked a generalized question . I gave you you a very informed answer . Do with it what you wish . It seams this is twice now I've got in a conversation like this on this site with the same results . The other changing the dynamic ( just to throw that word in again) of the question to there liking when thought needed by them to make a point . Like I said get some knowledge and come see me. No the first thing that pops up on a google search like the last disagreement I had on here. Bonjour !! I'm a French model!!


I have given you the process by which the presently produced chainsaws do closed loop fuel control several times during this thread - humorously, you appear to own some of these saws. Yet in your ignorance you state absolutely it is not possible, are repeatedly rude, call me an idiot and tell me to get some knowledge. Given your behavior I have no interest in interacting with you further.


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## Chris-PA (May 1, 2014)

Marshy said:


> As a whole it is complicated and I can think of a few advantages FI creates but only have time for a couple. For one, fuel atomization from the FI is WAY superior than carbs. One of the advantage this creates is lower combustion charge temperature and a better flame front during combustion. This also corrolates to more efficient burn of the fuel and more power gained.


That will be highly dependent on injector design and also fuel pressure (don't know what it is but it might not be that optimum given other design constraints). Carbs can atomize fuel very well, although these are pretty crude in terms of venturi design. They probably won't perform like carbs having booster venturis with multiple annular discharge ports, etc. Keep in mind though that the fuel is going into the case, which has lots of surface area and opportunity for fuel to condense out, even if it was well atomized.


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## Mike from Maine (May 1, 2014)

How many cessna's use fuel injection? It's got to better then a gravity fed carb.


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## KG441c (May 1, 2014)

MustangMike said:


> KG, I won't disagree with you about carbon inside the engine, I simply don't know, but how did you get a Madone 6 so heavy???? I've got a Madone 7 60 cm frame and w/o pedals it is under 16 lbs. Heck even my 08 5 series was under 20 lbs. I have also never heard anyone say their metal bike provided a softer ride than carbon, and everyone I ride with has gone from metal to carbon. If the seat and tires are the same, metal simply does not have the ability to flex in one direction but not the other the way carbon does. Regarding durability, my 08 Madone saw 4,000 miles a year for 5 years w/o any frame problems (I bent an aluminum wheel on a squirrel), but ditto the carbon wheels, no problems.
> 
> Is your bike 100% aluminum, or does it use carbon joints? And fork?
> 
> ...


My Madone was a heavy unresponsive rough ride with the basic Bontrager components and actually had 2 of them in 58cm. I read a review on Cannondale Caad 10, ( google the reviews), and decided to buy the all aluminum frame and build myself. Wish I had a pic. For u but recently sold it and quit riding. Cannondale Caad 10 frame, fsa force carbon handlebars,brakes,seatpost, cranks. All Dura ace 10 speed shifters,front derailluer,rear derailluer,cassette, chain, pedals and forget the seat but it was grams. Mavic Kysrium sl wheels and Michelin PRO road Race 3 tires at 150psi front and back. That all added up to 16.8lbs on scale at bike shop and a total cost of 3900$!!! Lol! Just my personal preference but both my Madones were stiffer rougher ride but the Cannondale was a more supple faster responsive ride. When I hit the pedals on that Cannondale ride it was all foward motion and smiles. It was all aluminum with top carbon components and by far the best ride I ever had. Got out of riding because the Rednecks in my part of the country saw u as a target! !! Lol! Cannondale just fit me better Mike and it was custom built with top components. Not sure what the Madone woulda weighed with the components I built the Cannondale with but u gotta admit as u r a biker that the Cannondale with thoso components at 16.8 lbs was pretty impressive. Dont knock what they have done with aluminum until u ride a Caad 10 if u still ride but happy riding and be careful!!


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## CR888 (May 1, 2014)

Theres more info on push bikes in this thread than a carbon fuel injected saw. Pity my bike has a motor.


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## MustangMike (May 1, 2014)

Thanks KG. I know what you mean about Road Rage, a lot of jerks here too, so we usually ride in a group. It helps, but I have had things thrown at me a few times and gotten into other disputes. Sorry you had to give it up, it is great exercise. Your bike sounds like it was real nice, especially for the price. One of my best friends also prefers an aluminum cannondale, but not because of handling or ride quality, he just thinks it is a little stiffer and more aero. Luckily, both those issues have been addressed with the new Madone 7, and I'm running the Bontrager A3 clinchers with the R4 tires.

I already had the carbon wheels, and I went with Ultegra (still and 11 speed cog), etc, and with a discount from the shop got a Madone 7 for under $4,500. If you don't select the top stuff, the price falls fast! (For those who don't know, fully decked they go for $11,700). The frame alone is supposed to go for more than I paid. if you ever get back into it, you will have to give one a try. 

Ironically, I had given up the biking back in 1975 after a close encounter with a car (not my fault, but I would have lost). Back then it was a Steel Frame 10 sp Schwinn. I was doing about 40 downhill and a lady pulled across the lane and stopped. Locked up both wheels, and was able to swerve around her at the last minute (I wasn't going to stop in time). I got back into it about 8 years ago, more enjoyable than running, especially with a group.


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## KG441c (May 1, 2014)

MustangMike said:


> Thanks KG. I know what you mean about Road Rage, a lot of jerks here too, so we usually ride in a group. It helps, but I have had things thrown at me a few times and gotten into other disputes. Sorry you had to give it up, it is great exercise. Your bike sounds like it was real nice, especially for the price. One of my best friends also prefers an aluminum cannondale, but not because of handling or ride quality, he just thinks it is a little stiffer and more aero. Luckily, both those issues have been addressed with the new Madone 7, and I'm running the Bontrager A3 clinchers with the R4 tires.
> 
> I already had the carbon wheels, and I went with Ultegra (still and 11 speed cog), etc, and with a discount from the shop got a Madone 7 for under $4,500. If you don't select the top stuff, the price falls fast! (For those who don't know, fully decked they go for $11,700). The frame alone is supposed to go for more than I paid. if you ever get back into it, you will have to give one a try.
> 
> Ironically, I had given up the biking back in 1975 after a close encounter with a car (not my fault, but I would have lost). Back then it was a Steel Frame 10 sp Schwinn. I was doing about 40 downhill and a lady pulled across the lane and stopped. Locked up both wheels, and was able to swerve around her at the last minute (I wasn't going to stop in time). I got back into it about 8 years ago, more enjoyable than running, especially with a group.


Sounds like a sweet ride. Thinking of mountain biking just for safety now but my heart is still on the road!! May get another oneday. I also had a close call in a group ride in Shreveport, La.
When riding in a draft line an idiot passed us in a car in a curve and met a oncoming car which he just pushed half the draft line
Over a large dropoff in the ditch!! Several people were hurt!! Anyway back to concept saws!! Lol! Cf on that saw is strictly for weight savings and nothing magical or special and should serve its purpose well! The efi concept on the otherhand is
exciting and something to look foward to but Mustang that darn
Saw may approach the price of a Madone!!! Lol!!


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## workshop (May 1, 2014)

A saw made of carbon fiber and fuel injected? I don't care what brand it is, I want one!


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## Marshy (May 1, 2014)

Chris-PA said:


> That will be highly dependent on injector design and also fuel pressure (don't know what it is but it might not be that optimum given other design constraints). Carbs can atomize fuel very well, although these are pretty crude in terms of venturi design. They probably won't perform like carbs having booster venturis with multiple annular discharge ports, etc. Keep in mind though that the fuel is going into the case, which has lots of surface area and opportunity for fuel to condense out, even if it was well atomized.


I partially agree with you. In particular, I'd fully expect the injector to out perform a carb on many levels otherwise what's the sense of having one? Yes fuel pressure will impact the atomization as will the injectors design but it still should atomize a lot better than carbs. Also, the fuel charge is still being delivered in the crank case because the lower half of the engine still needs lubrication. If you went direct injection you would need a way to lube the lower half increasing the complexity further with a separate lube system (this is how new direct injected snowmobiles do it). Plus direct injection is required to be at a much higher pressure than port injection.
In regards to carbs, they work on bernoulli's principle and are sophisticated highly engineered venturi by nature. They do a damn fine job but will never out perform FI IMO. By takin out the big bulky carb and replacing it with a throttle body the port runner design can be refined with superior geometry to provide optimized flow and create a boost bottle effect.


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## Chris-PA (May 1, 2014)

Marshy said:


> I partially agree with you. In particular, I'd fully expect the injector to out perform a carb on many levels otherwise what's the sense of having one? Yes fuel pressure will impact the atomization as will the injectors design but it still should atomize a lot better than carbs. Also, the fuel charge is still being delivered in the crank case because the lower half of the engine still needs lubrication. If you went direct injection you would need a way to lube the lower half increasing the complexity further with a separate lube system (this is how new direct injected snowmobiles do it). Plus direct injection is required to be at a much higher pressure than port injection.
> In regards to carbs, they work on bernoulli's principle and are sophisticated highly engineered venturi by nature. They do a damn fine job but will never out perform FI IMO. By takin out the big bulky carb and replacing it with a throttle body the port runner design can be refined with superior geometry to provide optimized flow and create a boot bottle effect.


Direct cylinder injection would be great, but that's not what this system is. I doubt it would be practical to create the pressure needed on a hand held device, plus the lubrication issue of course. It's just got one injector into the case. 

As to the question of what's the sense of having injection - that was my point (on a chainsaw anyway)! And even though Stihl designed one, they don't use it but for one cut off saw, so perhaps they haven't been able to answer that either.


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## bert the turtle (May 1, 2014)

I don't know enough to get into the fuel injection vs carb debate, but do you think the saw of the future will be able to tolerate E15 gas? That would be a winner, right?


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## woodchipper95 (May 1, 2014)

Id just like to have the bar, probably all I could afford!


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## woodchipper95 (May 1, 2014)

bert the turtle said:


> I don't know enough to get into the fuel injection vs carb debate, but do you think the saw of the future will be able to tolerate E15 gas? That would be a winner, right?



I would think most can now as long as its not in any form of phase separation. Water doesn't burn, by no means do I think E10 is good for a saw let alone E15 which is what most gas really is anyways. Even though the pump says E10.


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## Marshy (May 2, 2014)

Chris-PA said:


> Direct cylinder injection would be great, but that's not what this system is. I doubt it would be practical to create the pressure needed on a hand held device, plus the lubrication issue of course. It's just got one injector into the case.
> 
> As to the question of what's the sense of having injection - that was my point (on a chainsaw anyway)! And even though Stihl designed one, they don't use it but for one cut off saw, so perhaps they haven't been able to answer that either.


 
I recognise its not direct injection, my comment in regards to DI was more directed towards the others comments about why wouldn't they use it. I agree its just not practical for chainsaw appication.

Regarding your question about FI on a chainsaw, I believe I already offered some insight as to the advantages it brings. I think Stihl already fully understands those advantages also and will incorporate it into their production in due time in order to stay competative and complient with stricter emmission requirements. I dont see a way around it, its just a matter of time before they have no choice but to move in that direction; its happened with snowmobiles and watercraft already. Dont expect FI to hit the market anytime real soon but I think its in the works for production in the next 5 years. It will take a little time to refine it and make it affordable to the public, after all it's brand new technology, name one other "new technology" that hit the market the following year it was introduced to the public that was affordable and didnt have issues...


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## Chris-PA (May 2, 2014)

Marshy said:


> I recognise its not direct injection, my comment in regards to DI was more directed towards the others comments about why wouldn't they use it. I agree its just not practical for chainsaw appication.
> 
> Regarding your question about FI on a chainsaw, I believe I already offered some insight as to the advantages it brings. I think Stihl already fully understands those advantages also and will incorporate it into their production in due time in order to stay competative and complient with stricter emmission requirements. I dont see a way around it, its just a matter of time before they have no choice but to move in that direction; its happened with snowmobiles and watercraft already. Dont expect FI to hit the market anytime real soon but I think its in the works for production in the next 5 years. It will take a little time to refine it and make it affordable to the public, after all it's brand new technology, name one other "new technology" that hit the market the following year it was introduced to the public that was affordable and didnt have issues...


Time will tell - I'm actually quite familiar with FI and what it's advantages are (and it certainly does have many in some situations), but I don't think that in this case there are enough to justify the cost/complexity tradeoff. We shouldn't just assume that because it makes sense in other applications it will here too.


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## Marshy (May 2, 2014)

Chris-PA said:


> Time will tell - I'm actually quite familiar with FI and what it's advantages are (and it certainly does have many in some situations), but I don't think that in this case there are enough to justify the cost/complexity tradeoff. We shouldn't just assume that because it makes sense in other applications it will here too.


 
But we dont know the cost yet so how can you make the conclusion its not worth the extra cost? The tradeoffs are going to be at the cost of repair/troubleshooting if issues arise. The average Joe is not going to be able to work on these. and it might take some special tools. Otherwise, I dont see how the tradeoffs out weight the advantages IMO...


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## Chris-PA (May 2, 2014)

.


Marshy said:


> But we dont know the cost yet so how can you make the conclusion its not worth the extra cost? The tradeoffs are going to be at the cost of repair/troubleshooting if issues arise. The average Joe is not going to be able to work on these. and it might take some special tools. Otherwise, I dont see how the tradeoffs out weight the advantages IMO...


Naturally I am guessing on the costs, but a carb is extremely cheap to make. The MT/AT variants probably only cost a little more, as they only add a switch, connector and a stepper/solenoid valve, but get rid of the screws and the machining for them. The MT/AT electronics are incorporated into the ignition module and cannot cost much, as they only need a cheap microcontroller for that algorithm. 

The FI system has a lot more parts, must require more power (look at the separate generator). The control module is pretty big with more connectors. I can't imagine it doesn't cost more. But again, time will tell if it is prohibitive.


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## dl5205 (May 6, 2014)

7sleeper said:


> The data was presented by _*keksfriedhof *_
> 
> Benzinmotorsäge STIHL Carbon Concept
> Machbarkeitsstudie
> ...



It wouldn't let me on the German forum today without registering, and I haven't noticed it discussed here.

Does this saw appear to be a "factory big-bore" 441?

If so, it would appear they shed over a pound and a half, while gaining ~10cc. Pretty cool.


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## one.man.band (May 6, 2014)

7sleeper said:


> The data was presented by _*keksfriedhof *_
> 
> Benzinmotorsäge STIHL Carbon Concept
> Machbarkeitsstudie
> ...



usually power to weight is expressed as kW/kg.

not sure if it was a typo..... but did they come up with some kind of new statistic........ kg/kW? weight to power?

the power to weight is actually 5.4kW/6.0kg = 0.9

0.9 is very impressive nevertheless.

-omb


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## one.man.band (May 6, 2014)

JeremiahJohnson said:


> *Page 1*
> PRESS RELEASE
> 04/29/2014.
> *I can not believe - not impossible, STIHL chainsaw Carbon Concept*
> ...



error is in the above press release:

"- With the world's best power-to-weight ratio of 1.11kg per kW (without guide bar and chain)"

this is why it's a big deal:

thier way example: 3000 pound car with 500 HP motor = 3000/500 = 6

the way everyone else does it: 3000 pound car with 500 HP motor = 500/3000 = 0.17

oh well.

i'd like an 3000 pound car with 18000 HP as well. 18000/3000 = 6

hahaha.

-omb


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## nmurph (May 6, 2014)

I calculated a power-to-weight ratio of 2.23lbs/hp (and that's assuming their spec'd weight is more accurate than the weights they use in their product materials). A 7900 has a ptw ratio of 2.32lbs/hp using actual weights verified by multiple AS members.


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## one.man.band (May 6, 2014)

nmurph said:


> I calculated a power-to-weight ratio of 2.23lbs/hp (and that's assuming their spec'd weight is more accurate than the weights they use in their product materials). A 7900 has a ptw ratio of 2.32lbs/hp using actual weights verified by multiple AS members.



don't have actual #'s from members posts, but used weights from kwf testing site for about 30(?) saws.

most power-to-weights are just kW/kg (or HP/lbs.). if stihl lists them as kg/kW (or lbs./HP), do other manufacturers use the same convention?

for the 'standard' way of kW/kg (or HP/lbs.), the larger the number, the better. for kg/kW (or lbs./HP), the opposite is true.

7900 is impressive, in kW/kg. few which i have data for, which are better: Solo 681; Stihl MS461; MS650; MS880. no husqs.... have data for them, but out of this range.

if you want to talk torque, in Nm/kg. Solo 675, 681; Dolmar 6100, 6400, 7300, 7900; Stihl 441, 461, 650, 880. 

the only Husq close to these numbers is the 390XP. the 576, is lower, but out of the range of these listed.

as mentioned, don't have all saw #'s. but most of the current ones listed somewhere else.

regards
-omb


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## VinceGU05 (Aug 23, 2014)

I got to touch and dream about this today [emoji16]





Personally signed too! 



 

It felt as light as a 16" bar. [emoji15][emoji15]


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## Stihl 041S (Aug 23, 2014)

Really really want!!!


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## one.man.band (Aug 23, 2014)

how long is that bar vince?

the best power-to-weight ratio saw currently in production is the new MS661.

0.74 kW/kg

would be quite a combination with that bar.

-omb


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## VinceGU05 (Aug 23, 2014)

In all the excitement I didn't ask or check. But I would say around the 25" mark.


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## BBP (Aug 23, 2014)

I did a little research. According to a stihl article I found, that bar is 63cm & weighs 780 grams. That's 25" @ 1.72 lbs.


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## KiwiBro (Sep 11, 2014)

BBP said:


> I did a little research. According to a stihl article I found, that bar is 63cm & weighs 780 grams. That's 25" @ 1.72 lbs.


Steel and carbon fibre have seriously different thermal expansions. How do they account for that? Pliable adhesive bond? Rails made of titanium?


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## gunnusmc03 (Sep 11, 2014)

KiwiBro said:


> Steel and carbon fibre have seriously different thermal expansions. How do they account for that? Pliable adhesive bond? Rails made of titanium?


I think this bar is more a long the lines of an collectors item.


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## jeepyfz450 (Sep 12, 2014)

KiwiBro said:


> Steel and carbon fibre have seriously different thermal expansions. How do they account for that? Pliable adhesive bond? Rails made of titanium?


Dildonium...... unbreakable!


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## KiwiBro (Sep 20, 2014)

jeepyfz450 said:


> Dildonium...... unbreakable!


Often licked, seldom beaten.


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## KiwiBro (Sep 20, 2014)

gunnusmc03 said:


> I think this bar is more a long the lines of an collectors item.


Who would ever want to collect chainsaw gear that's unusable or they seldom ever use. 

No..wait...scratch that...guilty your honour. Sign me up for two of them carbon fibre bars. They'll look great on the big old PM Canadiens rusting away in the basement.


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## hartbilt (Nov 20, 2014)

Had to bump....a $40k firewood saw?...Mr. Stihl uses one of the 6 built to cut firewood at his home in the Fatherland...one bad motorsagen..











Wouldnt be surprised to see a fuel injected saw model by next year as the TS500i is already in production, carbon bars maybe a production piece soon as well.


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## XSKIER (Nov 21, 2014)

Nice.


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