Turbo Problems

[gtst93]

Hi guys I have a R34 with a Trust TD05 18g turbo kit on it.

The problem is that it isn’t holding boost above 12psi. when we try to put the boost up to 17psi the boost curve spikes at 17 then drops to 12 then up to 14 then back down to 12 and stays their. One of the guys form Trust Japan was over visiting Australia and he said to put a cat in and I will fix it. I did this Tuesday and is still the same but making less power.

Has any one else had any experiences with this or has any ideas?

thanks

[nuffsaid]

Is it the computer or parts of the car trying to protect itself from overboost?

I know satanic's R34 has a similar problem, the car has all these safety mechanisms which will rich, retard etc etc to stop the car from overboosting.

[gtst93]

i have a power fc and boost controller.

[BHDave]

type of boost controller?

[gtst93]

hks electronic

Edited March 3, 2006 by gtst93

[paulr33]

what exhast setup do you have?

try a dyno run with the exhaust dropped

it sounds like its a restriction and causing too much backpressure

[BHDave]

Does it by any chance have overboost protection similar to blitz units where the duty cycle is dropped by a preset amount when x psi is reached?

from you description of the response your gain is set very high as well which could also be contributing.

[gtst93]

what exhast setup do you have?

try a dyno run with the exhaust dropped

it sounds like its a restriction and causing too much backpressure

3inch dump into high Flow cat then splits into 2x2inch pipes into a little muffler then out the back.

it had no cat first and was doing the same thing and i got told to put one in because it didn't have enough back pressure.

it is a pain in the a$$

Does it by any chance have overboost protection similar to blitz units where the duty cycle is dropped by a preset amount when x psi is reached?

from you description of the response your gain is set very high as well which could also be contributing.

could not say my tuner sets it up.

their is also a r33 with the same turbo and same problem and he is using a blitz dsbc spec r

[AFRO]

sorry to bring up an old thread,,

but i've got the same issue,, though i've still got the stock turbo,, but have pfc,, and manual boost controller,, i set it to 12psi,, and it drops down to 8psi by the time it gets to redline,,, have a 3" turbo back exhaust and k&n panel filter,,,

(also, as a check, i tried it once at 14psi and boost dropped down to 10psi at redline)

thought it was the boost controller,, but its seems to work fine on another car,,

how would i check the wastegate actuator to see if its working ok??