R33 Boost Pressure Problem

[simongilbert]

Hi ppl,

I am ripping my hair out at this point. After having spent hours trying to figure this problem out and a few hours of research on google I am still at a loss. I am not the full bottle on turbos and am really in need of some help as I would like to save a mate some money.

Here is the problem.......

We have stock boost pressure e.g. We are still managing to boost to 7.5-8psi which as I beleive is the stock boost. But the second stage is totally missing. We had previously had the car up around 19psi and even clocked the 20 mark once or twice. REgularly it is running at 15 psi but it can easily take the 19-20's.

Here is what happened and also what I have already covered. I will also include what the vehical has as it is fairly modded. I can get more specific with the brands and anything else you guys may need eg. photos ect. Whatever you need to help me solve this.

The Scenario:

My mate stopped in for fuel (using 98) everything was working fine. Started the car and instantly noticed a difference in the motors sound. But just a lack of boost and also the air filter started making a heavy sucking sound as if it was blocked.

What the car has:

Aftermarket frontmount intercooler

High Flow Pod Filter

High Flow Cat with 2.5 exhaust and high flow muffler

HKS Electronic Controlled boost valve with three stage setting HIGH LOW and MANUAL (Manual setting is what cranks this bad boy to over 19psi)

Nice set of fat 17's with new rubber

Manual with heavy duty clutch

Imported from Japan with only 48k on the clock.

High flow fuel pump for extra boost

Decent branded BOV (Forgot to check Brand) Its a flutter valve too.

Motor in good shape (Not blowing smoke or using oil)

What I have done so far:

Cleaned Air Filter

Romoved all intake pipes

Checked blades on turbo-all good

Checked turbo movement-all good

Checked wastegate actuator-seemed slightly hard to move to me but I don't actually know how hard they have to work to move.

I replaced a few hoses that werent in to great shape

Checked wastegate movement-all good

Boost valve seems to be operating as normal-could be wrong

Thats about all I have done. So any help with some more test I could do or maybe if someone has had the same or similar problem that would be great. My mates car is a weapon and its a shame to see such a nice car going to waste. I am a commodore lover and even I want to fix this thing cause its such a great car to drive in. Probably the only turbo I would every buy oh unless it was a VL Calais ;P

Cheers ppl,

Simon.

Edited August 19, 2007 by simongilbert

[tek_01]

i didnt see a mention of what turbo your running. Your not running 20psi on the standard turbo are you???

[The Mafia]

i didnt see a mention of what turbo your running. Your not running 20psi on the standard turbo are you???

Me too.

I hope to GOD you aren't running that on a stock turbo.

Anything above 13psi will destroy it.

[simongilbert]

Um fairly certain it isn't a stock turbo. I think it has stainless steel blades. definitely not ceramic blades. All blades are still intact and turbo spools up just fine. It was regularly running 15 psi. And if we wnated some fun we would bost it up to 19. It lost traction in fourth......nice car. Anyway I can get some more specific specs for you. I wil see my mate to day and will get all the goods. The whole car has been worked by some asian bloke in sydney. MY mate flew there to buy it. I am not sure but I think that the motor may have had work done also. Thanks for your replies. Will get back to you.

Edited August 20, 2007 by simongilbert

[abu]

Um fairly certain it isn't a stock turbo. I think it has stainless steel blades. definitely not ceramic blades. All blades are still intact and turbo spools up just fine. It was regularly running 15 psi. And if we wnated some fun we would bost it up to 19. It lost traction in fourth......nice car. Anyway I can get some more specific specs for you. I wil see my mate to day and will get all the goods. The whole car has been worked by some asian bloke in sydney. MY mate flew there to buy it. I am not sure but I think that the motor may have had work done also. Thanks for your replies. Will get back to you.

LOL if its stock turbo hahaha

Metal blades would indicate a high flow. Best to check it before you blow it.

Thanks,

Abu

[The Mafia]

also, lol at anything above 11psi on the stock ECU

[simongilbert]

How would I be able to tell if it is high flow. HaHa....before we blow it.......if we havent already. But I think turbo is stil in perfect condition. At the moment due to our lack f boost its not going to be at all possible to blow.

[simongilbert]

Turbo: HKS GT2540 46T Max 30.1 PSI Limited by Compressor Wheel Speed

Bov: Blitz Flutter

Intercooler: T-Trust (Its a bigone)

Boost Control: HKS EVC

Exhaust: Definitely High Flow still not sure of brands

Boost Gauge: Factory Cluster Gauge and T-Sport Gauge with Max 30PSI

Engine: RB25DET

Year: 1996

Fuel: High Flow/Fast Flow Bosch

ECU: HKS2540 46T Installed by Garage Saurus

Injectors: Can't really tell but do look aftermarket.

So lads here is some more information for you. Thanks in advance......a carton is on its way for whoever solves this problem!!

Edited August 20, 2007 by simongilbert

[toffy]

ahh, the ecu wont be a hks 2540,odds are it would be a power fc if it was built in aus. first places i would look by the description you've written would be the inlet pipe from the filter to the turbo, in between the filter and theafm (might have something in there, ive seen wierder things), from there id go buy a cheapie bleed valve just to make sure your boost controller hasnt packed it in and from there id be looking at your manifold gaskets? let us know how you go with it