Daft problems Adjusting boost

Matt

Member
Ok I've now got my gtir running pretty well but I'm trying to adjust the boost. I'm aiming for about 13psi peak as I just want sensible power from it while I run the stock ecu & injectors (I've removed the apexi & big injectors for now)
Ok with the factory boost controller fitted the car try's to boost at nearly 20psi , how can this be on the standard ecu, could it have mapped of something or is it broken?

Next I fitted a manual boost controller that's the same design as the Dawes. With it on no matter how I adjust it I can't get more than 10 psi (I got no instructions with it which way round should it go?) there's 2 outlets the air in I had plumbed into the inlet & air out going to the actuator, is this right?

Next if I run nothing just the pipe straight from the inlet to the actuator I can get more than 7psi

I know I'm being daft what am I missing

Thanks
Matt
 

Matt

Member
With regards to the manual boost controller i think I've been screwing the wrong way for more boost so I'll try that next time I'm working on it but would stick like to know why the stock controller is boosting so high

Thanks
 

Matt

Member
Oh now I'm really confused, it looks factory fitted & pretty old. Maby it's something else It looks like a typical turbo actuator/solenoid with 2 outlets, it T's into the vacuum pipe that goes to the actuator, so one pipe goes to that & the other goes to the intake air pipe

Thanks
 

Fast Guy

Moderators
Staff member
Ooh, you might be on about the boost solenoid in the engine bay, on the front right of the engine/gearbox area. I'm thinking in car adjustment when you say boost controller.
Check it hasn't got a small hole drilled in it. I believe a 1mm hole could give you 1 bar if drilled in the right place. It's a few years since I've seen it talked about so both those figures could be slightly out.
 

Fast Guy

Moderators
Staff member
7psi will be right for that configuration, with the boost solenoid plumbed in and working properly you get another 2psi I think.
20psi is too much on that set up, it's suggest it's plumbed wrong or there's a hole/air leak somewhere.

Dawes device - you might be adjusting it the wrong way, only one way to find out. If it's still the same check it's not fitted the wrong way round. Many years since I had mine on, so can't remember which way it goes.

Edit I think I may be wrong - doesn't the boost solenoid cut 2psi or so when the det sensor kicks in?
 
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splmum

Active Member
Just a point, do you have the hose with the 'restrictor' still in place.
Without it you will be getting 7psi, with it you will get 10.6psi (Standard boost), with the hole drilled in the boost solenoid you will be getting c.14.5psi.
If no hole drilled, standard boost, if dawes fitted this can go to 18-20psi.
Without restrictor hose you will get 7psi and with dawes fitted possible 'anything'.
All this presuming the vacuum plumbing is correct, and with bodgy lines this all goes out the door, in other words it could be anything and unstable.
 
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