Loosing Boost Pressure On Stock Boost

[--{TRYDIS}--]

hi peeps just installed a boost gauge on my '93 R32 Gtst M-Spec and i noticed that when i flat stick it it hits 10psi but then starts dropping (not keeping constant pressure) any ideas why this might be happening? thanks mowie

edit: sorry typo error

Edited October 26, 2006 by --{TRYDIS}--

[sinistaGTR]

what boost controller

[--{TRYDIS}--]

im not runnin a boost controller just on stock boost i fitted an aftermarket boost gauge and it shows that im not keepin constant boost presure

[R3sp3ct]

Did you install the gauge yourself? And does it feel like the car has a prob or are you just reading what the gauge says?

I'd say your install is incorrect.

[--{TRYDIS}--]

well here's the thing it does feel like im loosing boost cos i get up in the rev range fast but dont hold for too long like it hits 10psi then drops to like 5 psi

[bj_dove]

Stock turbo i'm assuming?

The turbo is getting past it's efficiency range and dropping boost.

Get an electronic boost controller to get it to close the wastgate up at higher revs to try and retain boost.

Your gauge install is fine, and its the correct reading!

Cheers, Bart.

[--{TRYDIS}--]

cheers for the advice mate ill give it ago im now lookin for an apexi avcr

[r32matt]

Stock turbo i'm assuming?

The turbo is getting past it's efficiency range and dropping boost.

Get an electronic boost controller to get it to close the wastgate up at higher revs to try and retain boost.

Your gauge install is fine, and its the correct reading!

Cheers, Bart.

How could the stock turbo be going past its efficiency range when it comes out factory as 10psi? It should hold 10psi fine unless there is a vacuum leak or something. I would of thought something like 14psi would be past its efficiency range...

[Oblivion]

mine does it too...my guess, is that it is just old age, some do it, some dont...mine does it. try to block off you BOV. it helped mine a bit. mine went up then only dropped off a little after that. just means that you'll have to get a new turbo, no harm there. It shouldnt be a problem, just means not as much pull top end.

[Rolls]

Mine goes to 11psi then down to 10-9 at redline. It should hold it, maybe boost leak?

[bj_dove]

You'll probably find that out of the factory the boost wont hold to redline without the aid of some sort of boost controller closing the wastegate, as the manufacturer would aim more at driveability and midrange than top end, i say the boost drop is totally normal.

[R33S2]

Broken manifold studs? I lost boost, it was a cracked manifold and broken studs.

[NicsR33]

not sure if its related but my BOV was leaking and dropped factory boost from 7psi to 4psi. after this was changed and a boost controller was added it seemed to be ok.

[dbo]

As already mentioned i'd be checking your BOV and also Manifold studs/gasket, aswell as any holes in your exhaust. Friend of mine with a 4 door 32 was dropping boost, very similar problem to yours, and it turned out he had rooted manifold studs and a hole in his exhaust.