well i've had this problem for about a month now. seemed to happen a couple days after apex pfc install, but it might just be a coincidence.

in all gears at WOT, boost would fluctuate between 10 - 12 psi and at 4500+ rpms, when the secondary kicks in, i would boost at a steady 8 psi.

i have searched but i cant seem to find someone with the same problem as me.

i checked intercooler hoses, all seem fine and snug

what other hoses do i need to check?

i have been told that i may have a bad gasket, other's have told me that i my cat may be too restrictive and is not letting out enough pressure, and i have also been told that my turbo may need a rebuild.

expert opinion is needed. anyone who had this same problem fixed, please tell me what you did.


thanks,
jed

 

anyone?

 

Your turbo does not need rebuilt.

Since you just installed a PFC, look into adjusting the precontrol and wastegate settings. If you increase the boost level on the wastegate and increase the precontrol you should see the primary and secondary level out. Sorry I don't know more but that should be a good first step.

Dave

 

thanks dgeesaman!



i'll look right into that.


any other advice would be greatly appreciated

thanks,
jed

 

would anyone happen know the stock boost settings on the pfc?

 

You'll want the boost at 0.70 kg/cm^2, which is 10 psi. I'm not positive of the solenoid duty cycles, I believe they are around 56% for the first turbo and 64% for the second.

 

thanks goodfella, but i still seems to get 8 psi when the secondary kicks in

 

It could be a problem with the vacuum hoses/solenoids/check valves. Are you still running your original setup (ie no silicone hoses)?

 

yeah i believe so. I got the car last october and i haven't replaced any vacuum hoses. When i first bought it, it had the 10-8-10 boost pattern. But after i installed the pfc, i began getting a 12-5-8 boost pattern. so i'll take a look at the check valves and solenoids once i go back to my local shop (rotary power).

but if anyone else has any other solutions, let me know.

 

NEW PROBLEM!!!

boost pattern 6 - 4 - 6!!!

wastegate solenoid may be the problem. At WOT you can hear spool, but it also sounds like air is escaping from the wastegate. is this correct? or is it some other problem?

 

Time to replace the vacuum hoses/solenoids/check valves which might be a good idea since the condition is getting worse! Though, I would rather have low boosting problems than accidental overboosting ... I don't think low boosting can cause any damage?

 

so far i know i am going to replace the following:

check valves
the 2 turbo control solenoids
charge control solenoid
charge relief solenoid
and most likely the vacuum hoses from the turbos

is there anything else that i should to consider changing? right now, i'm just trying to get my turbos to boost at the normal psi.

 

Are you sure it's the wastegate, and not a boost leak (torn coupler, etc.)?

 

pretty sure it's the wastegates. The "sssssshhhhhhh" sound is coming straight from the turbos. but then again, i may be wrong.

 

If you hear air escaping then you have a boost leak, Are you still running the stock rubber couplers or are they silicone. Either way pull them off and check them for splits/cracks.

 

If you can hear a waste gate leak your the first.

 

ok so what is the best way to analyze this problem?

check couplers
check the check valves
vacuum hoses
solenoids

is that a good order to pinpoint the problem?

 

When you check for splits in the couplers you must REALLY check careful. Many tears that are gaping holes are almost undetectable at normal pressures. A quick check would be to seal some plastic wrap around the couplers (if possible then drive the car under boost and check to see if its still intact. I used this technique to find leaks before, simple and quick to isolate the area of the problem.

 

thanks phdmdrx7!

looks like i have 2 tiny slits in the coupler coming from the y-pipe to the bottom ic hose. ordered a new coupler from samco. hope it helps. if that fails, then i have a set of check valves coming from dick dale sometime next week.

 

No need to be gentle with the couplings when looking for splits. If you can't turn it inside out you need to replace it.