Anybody know what PSI this happens at? It would appear to around 16.5 psi, as this is when it cuts after fitting my Dawes Device.

I've adjusted the Dawes and now it only rarely cuts in 5th on WOT. Is it OK to leave it like this, as I rarley drive with WOT in 5th anyway. I assume that as it's not cutting in any of the other gears, it is not going outside of the permitted boost pressure and the map can cope with the boost level? i.e. the mixture is always rich enough?

Perhaps this is one for John Banks:- I've noticed that the turbo know spools up very quickly (97UK with 1.5mm Dwaes Bleed), can my standard map cope with say 3200 rpm 15.5 psi and 1/2 throttle? I think I'm getting paranoid, as the car just feels much better and responsive at low revs and I'm worried about running too lean.

Does any of this make sense?

Cheers,

Rob

 

Also interested to hear where fuel cut is on a UK MY97.

So BTTT

Cheers



Iain

 

I think you've got the fuel cut about right for a MY97. I would turn it down - any fuel cut under any circumstances is undesirable.

The fuelling on a MY99/00 copes fine with full boost over 1/2 throttle, and uses the airflow meter to control fuelling. With a 1.5mm bleed hole the part throttle boost is acceptable.

 

Thank you John

 

John,

How does the fuel cut work on a uk97? Does it just cut fuel when the manifold pressure exceeds 16.5 PSI OR does it have a curve which is some function of revs / timing / throttle opening etc?

If it's just always at 16.5 PSI, does this mean that at below fuel cut off, even in the worst case, the mixture is always rich enough?

Cheers,

Rob

 

The mixture is controlled by MAF and should be fine beyond the fuel cut. Fuel cut on later models is timer based - about 4 seconds over the threshold, but I have not tested it much!

 

Once again, thanks John