new 2012 models

[Skidad]

Obviously the DI outboard motors don't use an expansion chamber but what about the DI snowmobiles (which are a true DI not some half breed system). My guess is yes but without searching I really have no idea. Any sled freaks here care to comment...NH Rider where are you???

Just think of the possibilities without the need for a huge expansion chamber. Would be so nice

[GMP]

I do not think its needed and is a major advantage. From what I've read, one of the latest trends in DI tech is to inject some air with the fuel, I supppose to help disperse it, as there is not much time before the spark fires. Perhaps this would negate any loss of the air through the exhaust port from lack of a shock wave to keep it there. Just a thought. I'm no expert by any means and Im sure a few hours worth of research would bring you up to speed if they are interested.

[john01]

I hope they bring that little bike over here; I'd like to ride one.

[gg3]

Originally Posted by Skidad

Obviously the DI outboard motors don't use an expansion chamber but what about the DI snowmobiles (which are a true DI not some half breed system). My guess is yes but without searching I really have no idea. Any sled freaks here care to comment...NH Rider where are you???

Just think of the possibilities without the need for a huge expansion chamber. Would be so nice

Good point with outboards,don't get snowmobiles here though.
DI would halve the number of postings on this site!

[Skidad]

Originally Posted by gg3

DI would halve the number of postings on this site!

Nope (but that's a funny thought), It'll be a whole new can of worms to open

Following the Berg and KTM FI thread over on KTM Talk indicates to me it will be no different with DI once it arrives. KTM is picking their DI production parts suppliers this year BTW. This was from one of their top engineers and in a recent video on the 2012 bikes.

[Clay]

I'm not so sure that DI and EFI are the all they're cracked up to be for off road use. We use that stuff in a really unclean enviroment. The DI/EFI system in other vehicles very seldom gets put into mud and dust like off road motorcycles.

When I worked for Husaberg we had a lot of trouble with the EFI system. The bikes had a wierd cough/stall issue that wasn't fixed when I left. Mike Lafferty had a problem with his bike at the TX National Enduro that cost him the win. They told people that it was the fuel pump but Mike told me that they never did really figure out what happened. He quit racing that bike and only uses it for practice. Once carbs are jetted, there isn't much that can go wrong during a race. EFI can simply quit working with no warning. There were also lots of issues with tuning. A rider couldn't do it himself. He had to take it to a dealer and plug it into a computer program that was difficult to use.

One other wierd issue is that some of the bikes with EFI don't get scored at the National Enduros. The EFI interferes with the transponders. The NEPG is testing a new transponder that is supposed to fix this.

Clay

[nhrider]

Originally Posted by Skidad

Obviously the DI outboard motors don't use an expansion chamber but what about the DI snowmobiles (which are a true DI not some half breed system). My guess is yes but without searching I really have no idea. Any sled freaks here care to comment...NH Rider where are you???

Just think of the possibilities without the need for a huge expansion chamber. Would be so nice

The Ski-Doo ETEC's all have expansion chambers. It looks like the same size as a non-ETEC'S motor. They also have exhaust valves. The plugs are good for 10,000 miles. One pull and the sled starts every time. Runs and idles clean. Cleaner then the 4-strokes. No smell and no smoke.
The etec motor is still a simple motor. It is the computer that is doing all the work. Some say the computer could go...I don't think I have heard of one crapping out. I'm converting my fleet over to etecs in the next couple of years because the motor is really really good.

Check this video out
http://www.youtube.com/watch?v=8Og0J...e_gdata_player

Sent from iPad

[GMP]

Making computers do things, physical things, in addition to crunching numbers in mission critical process control applications is what I get paid to do. If something does go wrong, either from an operator error or a bug in my software, I have to make sure I completely understand why so it cannot happen again. For this reason, I have a handle on this. The ECUs used are extensively tested, and are not exclusive to one mfg. I had a Cannondale that I did a lot of my own custom mapping on, as well as a lot of electrical hardware re-engineering. That bike used the same ECU (Sagem, with an Optimum operating system) that was used in some Renault cars and the early Triumph Speed Triple. The bike got a bad rap for EFI reliability. I identified the problems fixed them, and it was solid as a rock thereafter. Some of this was electrical, some was thermal. Its all in the implementation and packaging, it has to be thought out very well and then life/torture tested. The Cannondale used off the shelf components like the fuel pump, and an external low pressure fuel filter that was easily inspected and changed. Never any injector clogging problems like the KTMs and Bergs. Due to the reverse motor, injectors right behind the radiator, airbox with temp sensor above the head, and header under the tank heating the fuel, there were some challenging thermal fuel and sensor heating problems to solve when the bike was ridden in a tight woods environment. Open air fast MX no problems. From what I see of the Bergs after a good look, with the high header and tight packaging, it doesn't surprise me that mystery problems pop up occasionally.

I think that 2stroke DI, while perhaps more complicated than EFI, would have an advantage over 4stroke EFI in that there is much less heat to deal with. Dirt is the easy part to deal with, heat is the devil.

[Clay]

I think that 2stroke DI, while perhaps more complicated than EFI, would have an advantage over 4stroke EFI in that there is much less heat to deal with. Dirt is the easy part to deal with, heat is the devil.


Glenn,
That makes sense. The HB problems got worse when the temps got higher. Do you think the heat issue on the 2Twould be less of a problem than on the 4T since the engine is not crammed so close to the tank?
Clay

[rgranger]

Originally Posted by gasgasman

Here's that hybrid.......

http://www.gasgasmotos.es/en/trial/3...-randonne.html

Is that a 4T refrigerator motor "4T monocil?ndrico, refrigeraci?n aire" or A/C motor