Losing Boost Pressure

[R338OY]

Hey all,

running a stock turbo on an RB25DET. Cat back exhaust at the moment. Never had any problems with boost until recently. I normally run 10-11psi with a manual boost controller.

Now my boost gauge tells me that when the turbo spools hard at 3-4000rpm the gauge's needle actually drops as pressure is lost, maybe a couple of pounds. If i hit it hard up to 6000rpm it's not as noticable.

I checked my intercooler and piping- all ok. Intake pod is ok. Boost controller ok. Boost gauge ok. The ONLY thing that made me think twice was my exhaust. The resonator and piping from it to the canon has rust holes. They leak exhaust gases.

Does this create a loss in pressure at the turbine housing?

Can this be the reason i'm losing boost pressure?

Thanks guys

[Simmo1985]

I got the same problem as this too (just posted in your squeaky clutch post coz I had that problem too haha).

Will be interesting to see what people suggest. Wouldn't think rust holes would be effecting boost.

[R338OY]

Lol our cars are crap

I thought it would have only a small relation to losing pressure.

I took off my side mount intercooler the other week and flushed it out, put it back on and had no problems. Had the man. boost controller for a month with no problems.

It's like loss of boost out of nowhere

[Simmo1985]

Hopefully it's something as simple as a lose or split hose somewhere..

Good old Skylines and there common problems... I had an 03 WRX for 8 months without a single problem before switching to my Skyline, had it three weeks and already had a few problems with it.. Although if I had to pick between the two I'd still choose the Skyline!

[trig]

Lol our cars are crap

I thought it would have only a small relation to losing pressure.

I took off my side mount intercooler the other week and flushed it out, put it back on and had no problems. Had the man. boost controller for a month with no problems.

It's like loss of boost out of nowhere

correct me if im wrong im only new to this

if you had a small leak, wouldnt your turbo just keep boosting by keeping your wastegate closed because your manifold pressure hasnt reached its desired point?

and i think 33's have something in the computer that floods thems when you try and go over 14-15 pound to save the turbo and engine if a hose blows off

do you have a noticable flatspot at wide open throttle??

im sure that would happen if you have a leak

but like i said, i could be way off

[SilverECR33]

Do you both also use a Manaul boost T ??.. just a suggestion.. You get what you pay for after all..