1978transam

hey guys, had my scoob about 2 weeks now, had to get back to a turbo car!
its a 94 wrx import.
induction kit.
big exhaust...dunno make.
blitz dv
think thats the only mods.
just wondering tho, according to my boost gauge, its only hitting about 9psi.
is this low? previous cars i had ran between 15 and 22 psi. whats the standard boost?
ive cleaned the 3P sol out with carb cleaner and made no difference.


now dont kill me!....... i connected a bleed valve to the lower port of the BS (taken off a previous car....dont worry, it was only on the scoob for a hr!) to see if it made any difference.
turned right down, in 3rd gear, it boosted to 6 psi. i then turned it + 4 clicks at a time.......and noted the boost reading, untill it got fully open and still only hit 9psi.
bleed valve is now safely back in the box in the garage......ill get me coat!.

just after some advise on what boost should be, and any posible causes if it is low boost.
thanx.
matt.

1978transam

sorry, should add ive used 2 gauges with the same results.

witchamptonscoobie

iTrader: (3)

mine is totally standard and is running 0.7bar which is 10psi nearabouts and mines a 98wrx import wagon

Glowplug

iTrader: (8)

Saloon or wagon? As said, you are about right for a wagon.

That said, it should of gone round with the MBC fitted between the BCS and the wastegate.

Have you done a fault code check with the 2 black wires?

Does the BCS click away freely, either in test mode or under light throttle?

Can you hear any 'air' coming from the DV??

1978transam

It's a saloon. No fault codes. Pulses ok on green connection test. No air coming from dv... it had a different dv when I got it, but changed for mine from my old 200sx. I don't know if I put the bleed value in the right place tho. I took the bottom pipe off the bs with the pill in it as this wasn't connected to anything anyway and seemed the logical safe place to try it. Was looking to increase boost 1, maybe 2psi, to 11 psi or whatever it should be!

Glowplug

iTrader: (8)

That is why the MBC had no effect, it should be fitted between the turbo and the actuator, the very bottom hose is just a bleed and should be connected to the airbox resonator as below.


What DV did you remove, you try replacing it and see if that makes a difference. If all is good on test and fault code, my first suspect would be VTA DV.

1978transam

the res box intake pipe was cut by the previous numpty....i mean owner, just below the pill, so cant connect back up anyway. the original dv was a pink forge one. i replaced it with my blitz blue one from my sx as its smaller and looks alittle tidier. they both had no affect on boost levels.
ill have a play with the mbc tom when i get home from work. which pipe should i fit it inline to? turbo outlet or actuator conection?

Glowplug

iTrader: (8)

If you remove the top and middle pipe from the BCS and fit the MBC in place of the BCS that will do it.

Only do this as a test though. The reason for the low boost still need to be found and rectified, not masked.

edit: ensure you block the hole on the resonator box to prevent the intake of unmetered/unfiltered air.

1978transam

Excellent. Do you know what the boost psi should be? And thanx for your help so far. It's greatly appreciated.

Glowplug

iTrader: (8)

If it is the OE ECU then 11.47psi. Would be worth checking the ECU.

1978transam

Just to check the engine code thing. I connected the black wires, and and the cel continually flashes. Is that normal? Have a vid if it helps.

Glowplug

iTrader: (8)

If it is a 'steady' on off on off on off... then that is an all clear. If it is flashes and pauses of differing lengths then that is a code, ie 4 long then 5 short will be code 45.

See this.

1978transam

Cheers. All clear then.