Boost Creep Help

Hi everyone.
Hope someone can help me with this one! I have a Profec b spec 2 boost controller and no matter what i try i can not stop the boost from creeping up.I have disconected the wastegate actuator to see if it hepls but it still creeps! Any ideas would be great.
Thanks
Gerrit

Has it only started to creep since you fitted the ProfecB?? Try lowering the gain.

no the boost has been doing this from the begining, the car was rebuilt so everything is new still running standard ecu and injectors other than that everything alse has been done.

Is your actuator adjustable??

no the actuator is not ajustable, but i have tried disconecting it to see if it would stop when the flap is fully open but it goes to about 0.1 bar at 4000rpm and then climbs to 0.95 bar at 7000rpm

Hay S14200sx

Sorry for asking but what turbo are you using?
Do you know the size of the exhuast housing?

Becuase if you jammed the wastegate open and you are still over boosting it sounds like the gasses might be building up to much presure before the turbo or that the exhuast wheel is just allowing them to flow through with less resistance then just going through the wastgate.

What size is that turbo?

It is a GT2871R with .64 housing internally gated

I had that same issue and had to get the wastegate port made bigger on my turbo.

Thanks Gary57
From what i have read on the net it seem there are 2 options one is to port the gate and if that does not work to use an external WG.Did the porting sort your problem out completely?

Its Strange that it would do that with a GT2871R with .64 housing.

But I would agree, Try Porting it
Or External WG

Off topic : Damn nice turbo you have there

Thanks

Yes 100%, if I opened the gate with the actuator off I could still boost over 1 bar. The port was 28mm and I got it made to 32mm.

Ok thanks.I will port it and hope it works, otherwise it will be the more expensive route of trying to fit an external WG.

Ok we ported the wastegate and there is still boost creep,instead of going up to 1 bar with the actuator disconected it now goes up to 0.8.So the lesson is don't use a GT2871R .64 on a modified engine, the exhaust side is far to small to handle all the air its getting from the engine and the compressor.

Damn sorry to hear about your problem, what you going to fit on now??

cant you just go get a bigger exh housing or an ext wastegate!???!

I don't have many options left i suppose i can try and get a .86 exhaust housing but i am not convinced that this will make much of a difference, i will have to live with it for now until i can get a GT3076 with external wg and a new manifold.

and what might you be doing with the old turbo then???

I will drive the car like this for a while still but if you or anybody are really interested we can talk.I would like to sell everything together as one unit ,that would be the turbo with the manifold and turbo outlet.The exhaust housing and turbo outlet are both ceramic couted and the turbo has probably done 4000km.