Fuel injection use on a 2-stroke???

[BuddyP]

Sorry, this is a little off topic as far as PT is concerned, but am looking for some feedback and thoughts from some of you fuel injection/Direct injection guru's.

First a little background. I drag race snowmobiles during winter. These are full mod sleds... nothing like what you see in showrooms other than the plastic is the same. And like all forms of competition everyone is looking to get that little extra. Aside from turbo's and NOS I'm wondering if a fuel injection system could be mocked up for this application. There are stock sled that come with fuel injection but this setup I'm referring to would be on a 3 cylinder 2-stroke (approx. 1200cc) running at give or take 9000-9200 RPM. To have a full adjustable fuel setup would be great. Currently we run around 52mm or larger carbs on motors this size for adequte fuel/air flow.

Any thoughts?

[Fuelie Fan]

If stock sleds have EFI, haven't you answered your own question?

[BuddyP]

No I haven't, current EFI is setup for 2 cylinders 2-strokes with semi direct injection at closer to 8000 RPM. Also I have no way of programming the stock ECU's to accomodate more fuel at higher RPM. Stock sled motors vs race sled motors are as different as black and white.

[EFI69Cam]

A friend of mine EFI'd his Yamaha 3 cyl awhile back. He used a Accel DFI. If you are interested in details, l can find out for you.

[Fuelie Fan]

My point is this: the only challenge of a 2 stroke, in my mind, was the fuel system. If the OEs have solved that, why not copy it? Otherwise, an engine is an engine as far as the electronics, you just have to set it up correctly. You'd probably have to fab a custom crank wheel if your particular engine was not fitted with efi. I would recommend getting an ecu that handles throttle body injection. They typically inject on every crank event, which would work well with a 2-stroke. You'd probably also have to do alpha-N calibration since i don't think 2 strokes pull a lot of vacuum. These are all easily done in most aftermarket efi systems. Your rpm range should not be a problem.

Do your bikes use seperate oil injection or mixed fuel? What do the factory bikes use?

[amx2334]

Outboard boat motors have been efi for years.Maybe there is something from some of the drag boat guys?

[MonzaRacer]

Microsquirt and Megasquirt

[newby]

Microsquirt and Megasquirt

definately second that.

if he gets MS running on his sled you know the snow blower and log splitter are next... or maybe reverse that.

[pdq67]

He, He!!

Right, the hand-held 215" BOP aluminum V-8 powered chainsaw!

pdq67

[70bird]

I don't know much about snowmobiles, but I remember being in an Arctic cat dealer in around 1995. The top dog in their line-up at that time was the Thunder cat. 900cc (I think) 3 cylinder with EFI.
The dealer told me it would do 160 mph!