only 12 psi, even with WG Disconnected????

[Go n 4 10s]

Ok I have searched the forums countless times and have had no luck. I am not looking for a boost leak, already checked for that and no luck. I have a 90 FWD laser It was bone stock for the longest time till i saved up and went all out. this is the mods i did:
20g turbo,
CX racing 3.5 thick front mount with 2 1/2" charge pipes
Type S BOV
GM MAF
MAF Translator
Walbro 190 re-wired
FIC 650cc injectors
3" thermal turbo back
Stainless o2 housing with External wastegate dump.
Tubular equal length Exh manifold
new ecu with raised Capacitors.

Now the question... the 20g started to leak oil, so I sent it back and it was covered under warranty, while it was off I put the stock 14b back on and re-tuned the car. My problem is it will only go to 12 psi in 2nd and up gears and only about 8 in 1st? Like I said it has no boost leaks what so ever. My tunning expert where i live said its B/C the stock 14b Cannot flow enough to fill the FMIC and charge pipes AKA Its to big for my little stock turbo? the front mount size is: 28" long (CORE) 8" high by 3.5" thick does this make sence? or another problem?

 

[delta448]

I'm thinking either the wastegate hole is cracking, or the flapper arm bushing is working its way out of the housing and causing the flapper to not completely cover the hole. Both are very common 14b issues, especially with some miles/abuse on them.

That intercooler is large, but it shouldn't limit your max boost at 12psi unless your engine is cammed and breathing VERY well. I use a CXRacing core that is similar in size and I was (unintentionally) able to push upwards of 24psi when my WGA vac line was accidently damaged.

 

[jjgrizz73]

Or it can possibly be a faulty actuator. Causing it to keep the wastegate cracked open. If you have a spare laying around toss it on and try it.

 

[Go n 4 10s]

I tried to put the one from the 20g on but no luck......When the car is at idle and first cold I can feel a little bit of air coming out of the dump tube, like its open But the actuator is closed all the way.......... So im guessing cracks???? but its weird B/C when the car was stock it would go to 14-16 psi all day long

 

[jjgrizz73]

How can you tell the actuator is closed all the way? If its bent or the spring is not working properly, it will hold the flapper open and trying to push it down will not work. Unbolt the actuator from the turbo and hold the flapper down with either your hand or using the actuator to pull it closed and feel for air.
Unless you are positive try it, because its easier to fix than taking off the turbo and replacing the housing.

 

[Go n 4 10s]

will try tomorrow...thanx again