I apologise if this has been covered a million times but I can't find anything and Search is down.

My MY00 is currently running with a Scoobysport downpipe. This is coming off soon so I can have the PPP done. What I want to do is refit the pipe afterwards partly for the extra oomph and early turbo spin up but mainly for the improved low revs/low gear/low speed "performance". Before I had the pipe fitted the car would judder when pulling away from stationary and always felt as though it was on the verge of stalling at lowish revs (maybe my right foot isn't heavy enough). The d/p cured this.

Anyway, I'm a bit concerned that if I refit my downpipe after the PPP then I risk problems with overboosting and detting. I guess a knocklink would cover the latter but what about the overboosting? Are there any products I can get that would protect me from it or are there any companies that can sort this potential problem out?

Thanks

 

See other active threads for more details (http://www.scoobynet.co.uk/bbs/thread.asp?threadid=70016) - you're unlikely to get 'overboost' with decat and PPP, but boost control will (possibly) be a bit slow.

This can lead (especially in cold weather) to a peak boost overshoot on WOT, followed by a severe undershoot as the ecu tries to catch up, followed by overshoot, etc., etc. - you can drive around it with a progressive right foot, or modify the restrictor, or change the restrictor for an adjustable needle valve (assuming you want to keep the factory boost solenoid).

Do it - the gains are worth the hassle

You don't mention what backbox you have - with the OE one fitted to mine, the boost issues were not so bad.

Richard

 

Cheers dowser; I don't suppose you know where I could get a modified restrictor from do you....?

I've currently got a WR Sport backbox but would stick with the PPP backbox when fitted.

 

Buy spare ones from your dealer and drill them out - that's what I did. I think John made his own initially, but now suggests using a needle valve instead (easier to adjust!).

Regards
Richard

 

hey Dowser , shouldn't the hole smaller in order for the actuator to read lower pressure?

 

Do it,
best value for money after PPP(and before MoTeC, GGR etc) got a magnex d/p std air filter prodrive exhaust but with HKS manifold got 272 bhp at dyno at 0.9 bar car absolutely no comparison with std PPP.

 

Stelios - sounds good; I assume you've had no overboosting problems?

 

SimonH, go for it...we have PPP, s/s down pipe, Prodrive exhaust, pipercross induction, Pace FMIC and HKS boost controller.

Did have overboost during v.cold weather, then fitted HKS which is now running at 1.25bar, no overboost so far.

Am going to use the "low" setting on the HKS as a "winter" setting if get overboost again.

Cheers, Moles Dad.

 

Cheers mole's dad!
Out of interest where did you source the HKS kit?