2 Strokes Down Under

We'll this has raised an eyebrow to say the least. Great to hear someone is keeping the dream alive.
http://www.iomtt.com/News/2016/February ... or-TT.aspx

Be very interesting to see how it goes.

Eskil reckons they have the fuel injection and emissions all sorted? Hmmm. That was a conundrum that sent the likes of Bimota broke. I hope he's onto it!

A lot has happened since bimota went broke.
Most outboard manufacturers have managed to get the strokers producing better emissions than the 4strokes.
Using better lubrication and direct injection.

It seemed like the end of the 2 stroke era was a little premature. There was clearly a lot of development going on and a breakthrough was inevitable but I guess it was too little, too late. They'd been on notice since the LC era.....

Yep.. it was much cheaper for them just to make the 4-strokes better.
H*nda did a very good job of shitting on the 2stroke so they were seen as dirty and basically beyond help.

yet honda built things like the CRM AR models with lots of tech in them too. Personally i dont see much of a market for this suter thing, its a nice diversion tho of course. I reckon plenty of us might like one, but wont be able to afford one, Jay Leno and a few of his cronies will buy em perhaps, but when those guys run out what will they do?

Keep sipping their margaritas on the beach with all the money they made?

LOL!

From what i've read there talking close to 200hp and around 140kg. All in a modern frame, suspension and tech. Should be a rocket and with the right pilot a real competitor.
Number 2 on my bucket list is to go to the isle of man, would be great to see a 2 stroke mixing it with the big boys there. (number 1 on the bucket list is to race a tz350 at phillip island). i'll keep working, planning and dreaming.

Well, as predicted, taking an untried/tested machine to the IoM, was not going to be pretty.
The Suter injection system didn't work too well in race conditions, & times were way slower
than what Bruce Anstey got on the old-school carbied 'classic' YZR 500 last year.

At least the rider was not too bad, from crashing it.. try again/better results, next time?

James W. wrote:Well, as predicted, taking an untried/tested machine to the IoM, was not going to be pretty.
The Suter injection system didn't work too well in race conditions, & times were way slower
than what Bruce Anstey got on the old-school carbied 'classic' YZR 500 last year.

At least the rider was not too bad, from crashing it.. try again/better results, next time?

Only if they put some carbys on it. My spies said it took an eternity to get going again after a slow corner, was great at WOT. Something only a carby can cure EFI just can't cope with long period WOT then getting back on the pipe.

Long periods of overrun was what I found hardest to tune when mine was injected.
Mind you... I didn't get a lot of time to play around with it before I stole the ECU for the Mustang.

But WOT was definitely wayyy better than my carbs, but part of that was probably 40mm throttle bodies with custom manifolds that were nowhere near as tight as the 90 degree 500 manifolds vs the stock manifolds and 28mm carbs.

hybrid wrote:Long periods of overrun was what I found hardest to tune when mine was injected.
Mind you... I didn't get a lot of time to play around with it before I stole the ECU for the Mustang.

Okay brains trust, whats the theory there. Sounds similar to what Sutor were suffering. Is the cut off from injection too lean, too complete?

Part of the issue is that 2strokes don't have a nice vacuum signal that you can tune from.
Mine was tuned using a mix of throttle position and RPM, as opposed to manifold pressure vs RPM. I don't know what Suter is using, but I would assume they have access to much better technology than I had. Reality is though, that their issue is the same. You need an accurate way to measure the air going in so you can add just the right amount of fuel.
Air flow sensors are easier to tune than pressure sensors, but they are generally pretty big and you have to find somewhere to fit them. The return pulse on a 2stroke may also play havoc with a flow sensor, but I'm not sure on that one.

My take on it is this:
The trick to tuning in this area is that you need enough fuel so that you have instant response when you get back on the gas, but not enough that you foul the plugs up. Mine was bogging down from too much fuel. I still think I should have been able to tune this out if I had the time and inclination.
I had other issues (ECU related) that made it very difficult for me to tune properly (it's hard enough on a bike anyway just to data log and tune) and didn't realise at the time. I have since had the same issues on the car and fixed them. At the time I was blaming the fuel pump and all sorts of other things, not realising that the ECU was giving up.

OzzyElsie wrote: Okay brains trust, whats the theory there. Sounds similar to what Sutor were suffering. Is the cut off from injection too lean, too complete?

Theory is simple, the ECU can't cope, you cannot write enough correction maps for what is going on at this point. There is not enough time to match the correction map to input parameters.