Boost Backing Off

[Cyo18r]

I have a r32 skyline gtst (rb20det) I have a few mods such as

Standed computer but it's had something done to it

Arc air box

3" exhuast

oil catch can

hks intercooler kit

hks blow off bale

turbosmart t boost controller

All othe things are standed.... I am running 12psi and soon as it hits full boost it stays at 12psi for not even a 1sec then slowly drops down to 10-9psi any one no why or got any iders....

Edited September 8, 2010 by Cyo18r

[R31Nismoid]

Get a better boost controller

Or a better actuator

[Cyo18r]

;( I wanna put eboost2 in it and a lil bit bigger turbo

I was thinking it mite have a leak some were or turbo to small or boost controller f**ked

[Hanaldo]

Yeh I get the same thing happening with my Greddy B-Spec II, the stock actuator can't hold that much boost.

[Cyo18r]

Also was a good turbo upgrade I want somthing like the standee but better I like how it comes on I want somthing that will come on boost down low rpm

[Hanaldo]

Sounds like you want a high-flow... Speak to Stao at Hypergear

[Cyo18r]

Ok were are they at.... I think I found the web site thanks mate...

[Cyo18r]

Anyone else got any iders

[Brezza]

sounds like its just your boost controller, i had a bleed valve and it did the same thing trailed off maybe 1-2psi

mind you i've got a GTR with -5's and stronger actuators, but the boost would peak at 19psi then trail off to 17psi

but now i got a e-boost street and it holds over 20psi fine all the way to redline.

[Cyo18r]

Ok thank for that

[Hanaldo]

What I've noticed with boost drop off when boost controllers are the problem, it tends to drop off towards redline. I would think that if the boost is dropping off immediately after hitting peak then it is because of the actuator.

In any case, the best way of sorting it out is to rule things out from the cheapest solution up. I'd start by talking to your tuner, they may be able to tell you straight away what the problem is.

[Cyo18r]

Yer it's kinda around 6500 7000 rpm

[Brezza]

Yer it's kinda around 6500 7000 rpm

i think that's just normal for a bleed valve

[Hanaldo]

I am running 12psi and soon as it hits full boost it stays at 12psi for not even a 1sec then slowly drops down to 10-9psi any one no why or got any iders....

Yer it's kinda around 6500 7000 rpm

Wait... What?

You're only hitting full boost at 6.5-7k? And your car revs higher than that for you to stay on throttle and notice that boost slowly drops?

[Cyo18r]

It hits full boost like 3500 rpm then when it's gets around 6500 rpm it's starts droping off from 12psi

[Hanaldo]

Gotchya

Yeh sounds like boost controller to me then, more common with bleed valves as Brezza said.