Boost Wont Increase

[ryan_o_grady]

Just need a hand with this situation.

Put a 25 turbo on my RB20.

I have put a hose from wastegate to the manifold and t'd in a GFB bleed valve.

The turbo is running sweet and at 5psi.

When i try to wind the bleed valve up it is having no affect.I have double checked and it is facing the right way (arrows to the wastegate) but yeah no increase.

Is this stuffed controller or will it have something to do with the setup for wastegate.

[BHDave]

Try it without the bleed valve for a start.

Also put your rb20 actuator on the r33 turbo for an extra couple of psi.

Your mods will also have an effect but i wouldn't expect the boost to be held that low by stock intercooler/exhaust.

[justin911]

dunno if this helps, but theres a restrictor inside one of those stock hoses that goes into the T.

[ryan_o_grady]

I have used all new hosing.

I wanted to keep the 25 actuator so that it could run low boost.

Yeps well ill try it without the bleed valve and see if it still holds boost.

[Paul Smith]

I have put a hose from wastegate to the manifold and t'd in a GFB bleed valve. [unquote] The hose goes from the wastegate to the turbo not the manifold.

[Wazz]

Paul Smith, try explain shit like that a bit more.. otherwise there may be someone stupid enough to try hook it up to the exhaust side of the turbo

[BHDave]

I have put a hose from wastegate to the manifold and t'd in a GFB bleed valve. [unquote] The hose goes from the wastegate to the turbo not the manifold.

RB25 trubo comp cover doesn't have a nipple to hook the boost signal up to like the rb20 turbo.

Either way the boost drop between the plenum and turbo wont be so excessive to cause the problem, if anything it'll be making the turbo work a touch harder.

[ryan_o_grady]

Yeah i know what im doing just had to compensate by the fact there is no nipple on the comp housing on the 25's.

Im assuming at this stage it is the Bleed valve just waiting to test another one.

[Al]

If all tests fail try replacing your spark plugs.

I had iridium plugs in mine, threw on a hi-flow turbo and the thing wouldn't boost over 10psi. After 2-3hrs of fault finding on the dyno, my mechanic decided to change the plugs to a V-grove type, (there was nothing visibly wrong with the iridium’s) the next run saw boost hit 22psi and making power. Dropped boost back down to 17psi and started tunning .

[ryan_o_grady]

Why would the plugs work before on 10-14psi with old turbo but not on a diff one as in my case??Also have iridiums.

[Al]

In all honesty i do not know . I was running about 12psi on the std turbo, then we bolted up the hi-flow turbo and would not go past 10psi, but made about 180rwkw (same as std turbo @12psi) As stated b4, we went through ALL other possibilities b4 we decided to try the plugs.

This may not be the case for yourself, just stating what i experienced, hence why i said; "If all tests fail, try replacing your spark plugs."

[TTT]

as a test, why not take the line off the wastegate and go for a drive slowly.

see if boost goes over the 5-6 psi you've been getting.

since nothing is there to open the wastegate, it should have unlimited boost so do it carefully and slowly.

at least this will test if your wastegate is stuck open or not.

[Al]

That's what we did on the dyno, while trying to figure out why it was not making more boost.

[ryan_o_grady]

Yeah I have tried that out.And yes it does boost above 5 psi hit about 15psi be4 backing off.

[R31 POWER]

lol ryan we both have boost probs.Yours does'nt go high enough and mine wont go low enough

[TTT]

well without knowing your tehnical abilities, I'll only comment that the boost controller you are using is brokend.

have you thought about the turbo tech ones?

there is one on the silvia NSW going for $25 or new for $35 I think..

see the thread in this section