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Hi guys just wondering if anyone could help me with a current probem with my RB20.

My R32 has been a project car and it only came of the shop a few months ago and tuned 3 weeks ago. I spent $10,000 on the engine forging internals, getting the turbo rebuilt, the works. When I got it tuned it was running like a dream (415hp atw on 19psi) and suddenly 2 days ago I was on the way to work and went to hit boost then all of the sudden it wouldn't boost past 10psi and started gargling at 6000rpm (the GT35-40R doesn't come on hard till 5500rpm, car redlines at 8500rpm). At first I thought it might have been the pod filter seeing as it's located in the front bar and it's been wet lately, (so it might have been sucking in oily water which would have clogged the filter), but I replaced the pod filter and it hasn't changed. I'm going to clean the air flow meter the next chance i get. I've checked all the piping and it seems ok. I've checked the spark plugs and gaps, but they were fine. Does anyone have an idea what it could be?

Any help is greatly appreciated. :(

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It's a Turbosmart bleed valve, i'll check that thanks.

The problem gets worse as you go up in gears too . . . ?

I noticed on the way home 2nite that it's only boosting to 5psi now as well, a massive power loss and it means the problem is gradually getting worse. :P

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Hey again guys,

I desparately need some help on this I have checked all I can think of and my mechanic doesn't know what it could be either. I checked the bleed valve and i think it's fine but i'm not sure what I'm looking at. My car barely drives like a turbo anymore, I don't know what to do.

Absolutely any help at all would be really fantastic,

Thanks - Sean

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if it was mine, i would check the spark plugs first, see what condition they are in then change them with normal copper plugs if they arent already in there.

Then give it a compression test to make sure its all sweet.

what are the specs on the engine, what cams, pistons etc are your running? also what injectors, coils, ecu are you running?

I doubt a bleed valve would cause this problem, it can effect boost but not it missing after 6000rpm. I would be looking more electrical, ie spark.

Edited by R34GTFOUR
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its a leak or a blockage.

Check all intake piping for leaks.. particularly small leaks around the piping joins. Has the car started sounding different at all ? you would hear an exhaust manifold leak if you had one... Could be your BOV not staying shut as pressure builds up... could also be something stuck in the exhaust blocking it up.

btw 310 (approx) rwkw from an RB20... impressive.

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The spark plugs were changed with the tune 3 wks ago and they were copper plated, they wouldn't go that fast would they?

I'll get my mechanics compression tester tomorrow, thanks for that idea

As for the engine:

Turbo full rebuilt

Bored 40thou with CP forged pistons

Spool H-beam rods

Port and polished head

TOMIE adjustable cam gears

standard cams, valves etc (they were machined though)

SARD 550cc injectors

Splitfire coilpacks

Apexi Power FC ecu

That's all that I can think of right now

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its a leak or a blockage.

Check all intake piping for leaks.. particularly small leaks around the piping joins. Has the car started sounding different at all ? you would hear an exhaust manifold leak if you had one... Could be your BOV not staying shut as pressure builds up... could also be something stuck in the exhaust blocking it up.

btw 310 (approx) rwkw from an RB20... impressive.

Thanks heaps I'll check the piping in detail, maybe I need som enew clamps? There has been a weird sound as I accelerate bu it hasn't been very loud, so I didn't think anything of it. Could it also be a gasket? How would I go about checking the BOV?

Thanks for compliment, alot of planning, money and hard work has gone into it (hence why I am currently very distraught). Kind of wishin I didn't do i to the 20 now, should've just got the 26. But I wanted to do something different at the time.

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