Can anyone tell me what the optimum revs/ max power is on the 899? ive got a tacho, and at idle it reads about 400-500rpm, ad when the engine sounds loudest it is about 2800-3000rpm. Is my tacho right or not?

Adam

no, its only reading half what it should be.

guessing the 899, like the sporting has two coil packs instead of a normal dizzy

Yep.Arc's right. Idle on those beasts should be around 900-800 rpm mark and so 2800-3000 max rev is around 5600-6000rpm, thats about right, but i think that has a rev limiter at a higher speed.

This will be due to that whole halfed reading thing that Pete has experience of, PM him and bring the thread to his attention for him to deliberate on it.

I think it's the choice of tach thats crucial here.

Liam

cant u just get a tacho meant for a V6 engine and that'd work?

V6? no, that'd be even worse - it'd read 1/3 of the true revs. You need one that can do a 2 cylinder engine because of the twin coil ignition system. The rev limiter on an 899 is at about 6200 revs btw.

sorry to drag yet another old thread up, im using the 899cc ECU on my turbo sei its been remapped.

when remapped will this increase the max rev limit or will it still only allow my car to rev to 6200RPM?

i have a Mckritch 1.1 sporting ecu too i didnt want to get this rewritten as i was going to sell it but if it allows me to get that extra 1000 RPM then i might put this back in?

anyone able to answer this for me?

cheers

gaz

gazzaman2k said:

sorry to drag yet another old thread up, im using the 899cc ECU on my turbo sei its been remapped.

when remapped will this increase the max rev limit or will it still only allow my car to rev to 6200RPM?

gaz

Click to expand...

In the turbo it'll need remapping for a different ignition curve or expensive mahem will result. I'd think that if you can change the curve, you can tweak the rev limit. But I may be wrong...........................

But I thought you were going Megasquirt?

gazzaman2k said:

sorry to drag yet another old thread up, im using the 899cc ECU on my turbo sei its been remapped.

when remapped will this increase the max rev limit or will it still only allow my car to rev to 6200RPM?

Click to expand...

Gaz, I half answered this one when i test drove your Sei. I had my old Punto's ECU remapped to a 7800 limiter. I had to request this when remapping it though else they've left the limiter at 6500 rpm.

I think you really need a after-market ECU to sort out a turbo properly as recent discussion with the new owner of that engine has revealed, the fiat ECU will work but isn't really good enough when you start to go a long way down the tuning road.

POWL said:

I think you really need a after-market ECU to sort out a turbo properly as recent discussion with the new owner of that engine has revealed, the fiat ECU will work but isn't really good enough when you start to go a long way down the tuning road.

Click to expand...

VA's literature states "The Electronic Management System has been re-programmed to adjust the ignition timing to suit the requirements of the modified system and still run on 95 octane fuel."

Now, I'd not run on 95 octane except in an emergency, but the curve still needs modifying. Detonation will destroy an engine in less seconds than you have fingers on your right hand in a turbo car. Emma's car runs pretty much the VAD set up but with the addition of nice Mahle pistons and an oil cooler. The pistons are a good step towards reliability -- as the pics show, they have big, big, ring lands and thicker crowns than the Fiat ones. They're also a lot tougher.

Improving the material spec of the top end (and the exhaust valves are another area where improvement is likely to be warranted at some point) is one thing. An aftermarket ECU will enable more control of all the important issues (boost, ignition, fuelling) simultaneously and may add an extra layer (intake temperature, knock) of reliabiity.

Which is not to put you off, just to tell it like it is.

The VA system is a perfect example of why I believe the stock ECU works but really isn't the proper solution. VA's solution is to fool the ECU into seeing a certain state of things it can handle and compensate with secondary systems. IMHO this is the wrong way to go about things as when OOB conditions arise the main ECU doesn't actually have all the information to make a proper decision.

Yes, but that's really an issue of ECU technology as it was then.

Interestingly, gmc motorsport who are Rotrex supercharger agents in the UK are running what is a piggy back system very much like the one VAD used with the Rotrex. Seems that with slightly fewer variables the piggy back works fine.

With the much better pistons I'm hopeful that Emma's car will hold together well.