I would like to increase the overboost cut on a MY00 PPP, just by one psi or so, Anyone know if this can this be done? And if so - how? I don't want to lose it altogether, just raise is a tad!

 

I would not go higher without either better cooling or a turbo.on track with PPP ECU and a Dawes MBC,intake peak temps. started getting a bit too high over 17psi. 16.5psi never went over 47c but after 7laps I had to pit at 18psi as we were over 50c.

 

I'm not taking the car on the track, just the road. So I don't want to run higher held boost, I would just like to raise the overboost cut-out a bit - so that with a decat downpipe I don't hit it on peak boost on very cold days.
Can this be done?

 

Pie,

Have you tried changing the restrictor for a larger one? This has been successfully used by several people to cure overboost with full decat systems on both PPP and STD cars.

 

Won't a different sized restrictor reduce held boost, as well as peak boost?

 

1. If you are using the PPP to control boost there are two issues. The actual fuel cut itself really is a secondary one. The primary problem is that when the ECU sees held boost over 17 or so PSI it adjusts the duty cycle to reduce it. I *THINK* a fuel cut lifter from say 16.5 to 20 PSI would abolish this and then it would hold whatever your restrictor size dictated, but I am working on this at present.

2. If you are using another device to run 18 PSI on the road it is not unreasonable I don't think to move fuel cut up to say 20 PSI. Whilst setting the EBC up in my car I had a few surprise fuel cuts whilst overtaking things - a tractor once, truck another. Just keep your toe in at 3/4 throttle and it is fine, but you do use up some of the safety reserve you had - luckily I always leave LOADS for overtaking and always overestimate the space I require.

You can raise your fuel cut with an HKS FCD or try some of the DIY projects if you are handy with a soldering iron.

 

Jon,

I agree about 20psi limit, and I like the sound of your fuel-cut lifter! Keep us posted on developments.
Cheers,

Pie.