Rb20det Dropping Boost. Need Some Advice.

[robots]

Hi!

My setup:

A31 with swapped RB20DET.

FMIC

bosch 040

3" turbo dump

rest stock rb20de exhaust with no cat

Boost gauge is connect to one of the vacuum hoses at the intake manifold.

No boost controller.

and a cheap pod filter

My intake pipe is somewhat inconsistent(factory rubber hose was cut with the motor, had to do some ghetto shit)

Engine Idles fine. It should mean that there are no leaks after AFM, or idle would be high or something.

Boost gauge is connect to one of the vacuum hoses at the intake manifold.

Now about the driving.

Full boost by 3000rpm. was 0.7 when first installed, later when I was fighting with this boost dropping problem I've moved an actuator forward. Now it boosts 0.8 at 3000. But still drops to 0.5 by 6000rpm. Start to drop at 5k+. Same as before.

I've tried to drop the exhaust to check if it would help.

Full boost by 3k, would drop to 0.6 after 6k. Opposed to 0.5 with exhaust on.

I tried to clean injectors, throttle body No change )))

Also the when turbo starts to spool its kinda very noisy. I watched some videos on youtube and with inside cabin cam, it doesn't make much noise inside.

My one on the other hand is so loud, that I can hear it very well inside. Its actually loud.

Now my ideas:

1)Leaking BOV ??? Can someone tell how would it affect my dropping boost or noisy intake?

2)Leaking gaskets ? Exhaust mani/turbo ?

3)Get actuator pressure readings from plenum, not from compressor housing ?

4)Leaking in intake/intercooler ?

It really starts to get me, I can't feel the stock power And the noise.

Any suggestions, comments, ideas are welcome!

Thanks!

P.S.

Maybe it has something to do with the leaking or stuff.

But driving like a granny, shifting before 2.2k rpm hardly gets me over 350km/tank (~53litres)

Smooth accel, deceleration, few short trips.

Edited June 24, 2007 by robots

[Jsikalias]

iv got the same problem but mine drops to 10psi from 14psi and i got a gcg high flow turbo with the standard wastegate so i think that might be my problem...

[Jsikalias]

there is a hole in my intercooler core just found the problem

[silver gts-t]

i dont see the problem, its standard turbo right? no boost controller?

so its spiking to 12psi, standard rb20 actuator is 10psi i think, then above 5k boost is dropping to 8psi..

thats what my stock rb20 used to do.

[robots]

A lot of people don't have those issues, they run stock boost up to redline no probs, even more. So something is fishy here Thanks for the reply by the way !

[cln]

im with stilver gtst; my stock turbo used to full boost by 3k then die in its ass. even with a ebc i doubt your stock turbo could hold all the way to redline

[Cubes]

My old rb20det with the stock turbo used to run hit 10.9psi and hold to redline.

BUT... that was with a full exhaust unlike yourself.

Your still running a stock rb20de exhaust. Mine with the stock exhaust from memory was 9psi.

[Stronzo]

hi,

i`ve got the same problem, rb25det neo, stock turbo, no cat and stock BCNR33 exhaust. Full boost (0.85) at 2500-3000 dropping to 0.6 after 5000rpm. I played with boost-controller, especially with "gain" function with no positive results. It still dies after 5000rpm.

btw my turbo is pretty noisy too -- so i have to ideas:

- it`s turbo dying

- stock exhaust = evil

[robots]

Stronzo) На нисме есть такая тема уже )) Почему там не отписывался ?))

[GTAAAH]

Mine on 12psi using a turbotech boost controller and 3" zorst used to hit 12 psi then drop to about 11, and before the controller used to go from 10 psi - 8.6/9psi i had heard it was pretty normal for the stock turbo to drop a bit, considering the size, if that helps