Been working on a friends 93WRX today, had exhaust leak so replaced downpipe and uppipe gaskets. Car is Power FC mapped and running an E-boost controller. Problem is I can't get 1 bar boost before 4k in any gear.

Spec is

Rebuilt standard engine
Standard 380's
HKS Filter
VF 22
Gruppe-s headers and uppipe
3" bore full decat system

I am thinking that the VF 22 could be the issue, whether it's faulty or just to big for the set up. I also think maybe size of up-pipe may also be a factor, it looks like the bore is approx 50mm.

Any ideas ?

PS. I have also checked spool with a dawes and had the same spool results

 

Any wise words ?

 

up pipe is too big!
turbo is quite big! what power are you looking to get?
the headers you have are not needed at this level, you would have been better off with ported std headers, such as the ones that Harvey Smith can supply, he will also be able to supply you a suitable size up pipe, these work really really well.
You will want bigger injectors (yours will max out quite soon and run lean) and a walbro fuel pump as well to get the best out of this little lot and idealy get another ECU (APEXI etc)so you can map it all to the car

 

I think the turbo and up pipe are the problem, I've been in a similar situation and switched to a VF34 and got much better results, 350bhp. The VF22 is great if you are looking for top end power or use alot of revs to keep it on boost, ie on a track/drag etc but it's at the expense of power low down. Sounds like you need 550cc injectors.

 

Yeah I know the turbo is too big for the job but the spool is 'really' bad, in first and second gear your lucky to see 0.8 bar even at high revs.

Car was purchased with this set up, I have suggested fitting standard headers and up pipe as power goal is not large (circa 320). It already has a walbro and has been Apexi mapped. So I know it will need 440's also and a remap. We were just trying to get it the best we could as it stands.

I would have thought is reasonable to get 1 bar by 3500rpm even on current spec but it's not anywhere near that.

Clive

 

Any more ideas ? Weak actuator ?

 

you could try disconnecting the actuator boost pipe and gently driving it and see what boost it goes to, obviously you will need a boost gauge to watch to do this? have you got the restrictor in the pipework to the actuator?

 

I have tried running car at just actuator pressure and got 0.6 bar which is what I expected. However would this tell me if the actuator is weak ? Will removing the actuator boost pipe tell me anymore ?

 

Top for anymore help

 

There was a mention of oil feed banjos on here some time ago, where a TD series had been changed for a VF but had kept the TD oil feed bolts. I think it allowed too much oil into the roller bearings on the VF which slowed spool. I know I had to change both the oil feed banjo's when I went from a VF22 to a TD05.

 

Thanks for that, think I have heard that one before also, I will get my mate to ask the former owner.

 

Apparently turbo was fitted with th VF oil feed, so that's another thing off the list

 

You could change the P20 exhaust housing for a P18, for better turbo spool but you will lose some top end power.

Banny

 

The Vf22 is renowned from suffering from pretty glacial turbo lag. It only gets into it's stride above 4000rpm.