Posts
3051
Joined
8/20/2009
Location
Perth
AU
Edited Date/Time
6/24/2013 1:15pm
This is from the latest Australasian Dirt Bike...
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ARE INJECTED TWO-STROKES A MYTH?
JOACHIM SAUER, KIM PRODUCT MANAGER
"We have been working a lot in recent years in order to get the injection system ready for our two-strokes. I went out into the market last year and visited lots of dealers and spoke to hundreds of riders and I asked them if they would like a two-stroke injected bike. Everyone said, 'Great! When will it be ready?'
"I then said, 'Would you still love it if the price was close to the 450/500 EXC?' Also, instead of just a carburettor and ignition, you would have to deal with pumps and all the complexities of such a system, which also adds 2kg of weight. It would make the whole thing so difficult to deal with you would not be able to change the piston at home anymore.
"From the beginning, I could see their enthusiasm get less and less, and at the end, out of 100 people I asked, there was not even five people who would like such a system. So we decided we won't introduce it until the rules (homologation) force us to introduce it. This will probably happen with model year 2017. But if we had to do it next year, we would be ready. But we want to keep it back and do some more testing.
"I've been doing lots of tests [on the injected two-stroke] and the major benefit is that it has a very clean engine and a safe carburettor setting. If I'm on the rich side at sea level and I go up into the mountains, it will be too rich up, so this will be history [with injection]. I did not have smoke or that hesitation in front of an uphill when I did some trailriding, and I need quick response. Sometimes it feels as though the bike is not ready to get up, so the fuel injection has a major benefit in terms of engine behaviour and running. You can make different maps that make the bike completely different".
And for those two-stroke fanatics, Joachim admitted the two-stroke would not lose that powerband hit.
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Seems like the injected two-stroke is not quite the panacea that many think it will be.
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ARE INJECTED TWO-STROKES A MYTH?
JOACHIM SAUER, KIM PRODUCT MANAGER
"We have been working a lot in recent years in order to get the injection system ready for our two-strokes. I went out into the market last year and visited lots of dealers and spoke to hundreds of riders and I asked them if they would like a two-stroke injected bike. Everyone said, 'Great! When will it be ready?'
"I then said, 'Would you still love it if the price was close to the 450/500 EXC?' Also, instead of just a carburettor and ignition, you would have to deal with pumps and all the complexities of such a system, which also adds 2kg of weight. It would make the whole thing so difficult to deal with you would not be able to change the piston at home anymore.
"From the beginning, I could see their enthusiasm get less and less, and at the end, out of 100 people I asked, there was not even five people who would like such a system. So we decided we won't introduce it until the rules (homologation) force us to introduce it. This will probably happen with model year 2017. But if we had to do it next year, we would be ready. But we want to keep it back and do some more testing.
"I've been doing lots of tests [on the injected two-stroke] and the major benefit is that it has a very clean engine and a safe carburettor setting. If I'm on the rich side at sea level and I go up into the mountains, it will be too rich up, so this will be history [with injection]. I did not have smoke or that hesitation in front of an uphill when I did some trailriding, and I need quick response. Sometimes it feels as though the bike is not ready to get up, so the fuel injection has a major benefit in terms of engine behaviour and running. You can make different maps that make the bike completely different".
And for those two-stroke fanatics, Joachim admitted the two-stroke would not lose that powerband hit.
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Seems like the injected two-stroke is not quite the panacea that many think it will be.
thats what you tell the ignorant to scare them away from something you dont want to introduce yet. just tell them it'll be more expensive and leave it at that, but dont exaggerate it to make working on an injected 2 stroke seem like a nightmare
I don't understand why they think people won't be keen to buy FI 2 strokes. All the major OEMs have the tech (Honda had FI on the 2 stroke NSR500) just no one wants to do it. If KTM sold an FI 2 stroke range you can bet Yamaha would either lose all their sales and stop selling 2 strokes, or get their shit together and stop selling their 2000/2006 YZs as 2014 models.
What all this boils down to is that the EXP-2 has about the same real-world performance as the 780, but with substantially better fuel economy and lower emissions.
(the NXR780 was their Rallye-Thumper-Twin at that time)
The Shop
Even still, a piston change would not require much more work, only real difference would be the presence of said pump, and an injector in the head...
How about if I just mix some metaphors? You can lead a horse to water, but you can't cure stupid.
He explicitly states that if they had to roll it out next year they were ready.
Ski-Doo e-tec sled owners feel free to chime in with your experience.
I was working with a few hard-core sled guys over the winter to try to adapt a fuel-injection system onto a YZ250 2-stroke. Ended up going back to same old carb because of the added complexity ($$$$) and problems with adapting off the shelf multi cylinder systems to work on a single. Technology will continue and I am sure it WILL be an option....in the future.
Stiil working on it, but the YZ250 is a really solid engine to start with. The only real benefit we see so far is not having to re-jet for elevation, which is definitely NOT a good enough reason to justify all the extra complexity and expense.
Bombardier is doing incredible stuff with 2-strokes! The pic below is an 800cc twin putting out 163hp!!
www.ski-doo.com
there have been injected 2-stroke performance engines for over 20 years. Arctic Cat and Polaris both had battery-less efi in production by 1993. there is absolutely no fundamental difference between the 2-stroke architecture in a snowmobile and the ones found in dirtbikes.
The only advantage EFI has is a self adjusting mixture, and the only advantage DI offers over "intake" injection is emissions. both systems can generate perfect mixtures for all intensive purposes, and therefor "clean" mixtures, but neither system can make more peak power than a "slide" carb.
I think, like other people of mild or greater intellect (...and the KTM engineers), the benefits (not having to know how to tune a motorcycle properly) don't outweigh the cost and complexity increases. I would like injection as well, but I don't want to pay for it, and I don't want clean fuel screens and injectors, and I don't want to send my "little black box" away when I just could have reached into my bin of jets. Most importantly...I'm dreading the proposition of $10,000+ 2-stroke dirt bikes. Hell, I was concerned when KTM put e-start on it's smokers. ...and now I have 2 2013's, both with e-starts removed. What the hell did that cost me? I have no idea, but it was all waste, I can tell ya that much because there hasn't been a time yet where they didn't start with one stab.
On snowmobiles, it is a different story. Sleds go through huge swings in atmospheric conditions and the carbs are buried in a mine-shaft somewhere in the center of the sled. You take into account multi-cylinder configurations, cold starting, increasing demands from the EPA, and the fact that snowmobiles are already comparatively expensive, it makes much more sense to incur the extra cost and complexity of fuel injection. ...and by the way, Ski-Doo didn't have to invest much to implement their direct injection. Those technologies were afforded to them by BRP subsidiaries Johnson/Evinrude and Orbital Corp, who spent hundreds of millions developing that system.
You should all listen to the engineers on this one, especially since they say they are trying to save cost and complexity...because they never try to do that. Thats the bean counter's job, and that's how you know the engineers are serious about this one.
Pit Row
My guess is that for the most part the technology is sound and ready for sales.
Rotax is an Austrian company and I would be surprised that there is not some sort of tecgnology sharing being done.
fortunately, anyone who wants the Orbital DI technology is welcome to it. They publicly announced their willingness to work with any manufacturer out there in a bid to "help" lower polution. They have licensed their DI tech to many, many manufacturers all over the globe. (Appearantly their board of directors are full of suedo-eviro-types with aspirations of selling oil under the guise of saving trees. ...brilliant!)
there are no specific clauses by the EPA that specify the differences between engine architectural types, they only do that with fuel types... you are reffering C.A.R.B., which only exists in California.
what you dont realize, is that emissions are based on an average per manufacture, an overall "carbon foot-print" of the entire model range. If you have a bunch that are under the limit, then you have room for some that are over. Thats why manufacturers label and sell machines as "competition only," so that those models are not included into their "average" emissions quota.
it is true, that by doing this, these models are exepmt from certain status', but that decision is solely up to the manufacturer.
who cares about trail bikes and red-sticker this and green sticker that. lets just hope California falls off into the ocean. and then the rest of us can get on with riding our dirty "competition" only machines wherever the hell we want. like we always did.
If this kind of system ever makes it to mx/offroad bikes, i would be looking at buying a 2 stroke again for sure !
something else that people outside of snowmobiling might no know is the amount of 2 stroke smell you and your gear acquires during a day of riding. The exhaust is always in front of you. The E-tecs are so amazingly clean they don't even leave behind any of the typically visible "blue" smoke that other smokers do, and there is almost no oil/smoke odors as well.
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