Why aren't there any? Why did Honda drop the FI Itoh tested (and raced, if I remember) on the NSR500? What the obstacles? I thought the problem with the Bimota V-Due was meeting emission standards while remaining usable. GP bikes don't deal with emissions, right? What's holding them back?

Hi Papa,

The biggest problem was that throttle response was a little TOO good. Carburators employ a sort of simple mechanical fuzzy logic that softens the connection from the throttle to the tire. I have looked at one of the last Aprilia 500 twins that used fuel injection. It did make more top end horsepower.

I have a friend whose company produces two stroke racing engines. I have helped him with development in the past and now he wants to try to develop a FI system for a racing application. It would initially be four wheeled, so that should cut down on the highsides!

Rocky Stargel
Team Stargel

Fuel-injected karts? :cool:

Why can't they soften the delivery on FI bikes?

There is no great gain of using FI in a racing application engine if fuel mileage isn't an issue. At WOT, carburators do a pretty good job of metering fuel, sometimes better than injectors.

Remember, FI requires a fuel pump (weight) and more electrical load for the injectors and a bigger ECU. That nice, small fly wheel GP bikes have will turn into a diesel sized magneto!!!

The biggest gain with an FI on a 2 stroke is part throttle efficiency. And beleive it or not, the biggest gain in driveability there is brought on by the use of an Induction ignition system as opposed to a capacitive (because of longer spark duration).

The only cases where I saw an improvement in horsepower was when the injection was semi-direct (thru the intake port windows) where the cold charge seems to impede detonation and permitted leaner calibration.


OYTZ

Bimota tryed with the V2 500 twin.It was a disaster.Some many problems with the FI that made the preproduction bikes unrideable.Tons on money wasted and then Bimota decide to pull the plug.What a shame.:(

Yeah, tzrider, when you put it like that, it seems FI isn't worth bothering with on 2-strokes. More than power gains, I was thinking about it might be easier/quicker to "re-jet" and get it right for the track/weather conditions.

Need more power?.Get a bottle of NOS.Check this page out.Click on the 9 seconds pass link.Boost the volume.Now...that's power.
http://www.purplehazeracing.com/site/index.asp?DL=419&page=3030

Wasn't the Bimota V Due a direct injected (DI) two stroke? Kinda like a 2 stroke diesel used in some heavy duty trucks, now those are some wild sounding engines!!

I think a standard crankcase intake port fuel injected two stroke would be great, but the equipment to support it on a GP bike would probably add some weight.

http://www.bikelogic.com/Converts/Bimota_Vdue_Report_Final_Web.htm

Pretty good write-up about what was wrong with the V-Due

Basically incomplete engineering and testing......go figure

Thanks for the thread!

I used to want a V-Due so bad. What a shame.

l

Orbital direct injection for two strokes...? Did well in automotive applications.

What application in the automotive industry did it work well in ??

I'm only aware of one gasoline engined vehicle with direct injection that works well at all and it is the Audi R8 LMP car.

The advantage (supposedly) is not in power, but economy.

Originally posted by WERA74
Orbital direct injection for two strokes...? Wasn't Orbital involved in something (a Honda?) that raced Paris-Dakar some years back?

I dunno about Paris-Dakar but Orbital was installed in shitloads of scooter and one Sea-Doo engine (947 DI).

IIRC, Orbital had a fleet of 3 cylinder 2 stroke running for a company or city in Aussie land.

Google for the rest.