boosting question

[racer 13x]

i tried using the search but could not come up with an answer to this so here my question: how can i get my boost to stay below 7 psi? i tried both my dawes bc and greddy profec 2 from my probe and no matter what my car spikes to about 12 psi at about 1500 rpms even while sittin in the garage just revving it up. Any ideas? thanks

btw its a 89 mustang with 88 turbo coupe everything just about

 

[WHTLTHR79RS]

My son just popped a head gasket on his fresh SVO motor because we had NO pressure signal at the WG actuator. "T" in a line to operate your guage just at the connection to the WG and varify that your WG is getting a pressure signal. Then find a hand pump that is used to pressure check a radiator, and apply 10 lbs to the WG actuator and varify that the rod and valve move. that will be a start.

Neil

 

[Red_LX]

#1, check your timing and cam timing because you shouldn't be getting boost in neutral.

#2, the stock actuator won't go below 10 or 12 PSI, I can't remember the amount. Wastegate actuators have a preset limit that you can't go below. You have to find a lower rated one if you want the boost lower.

By the way, why are you limiting it to 7 psi? Don't tell me you put a turbo on an n/a engine.

 

[hotcobra03]

I owened an 88 coupe and had brought fords book to work on it.mine did something similar .ran great at 30psi my gauge would pin buzzer buzn just with touching.i changed solenoid also they had 2 different turbos found out when replacing.if thier is still a tag on it look at it A or B .auto was made to run 10psi and stick 15psi .any more info is no problem

 

[65ShelbyClone]

Like they said already, verify that the wastegate actuator is functioning and check the ignition and cam timing. Retarded ignition will make boost come on much faster and likewise cause EGTs to skyrocket.

I owened an 88 coupe and had brought fords book to work on it.mine did something similar .ran great at 30psi my gauge would pin buzzer buzn just with touching.i changed solenoid also they had 2 different turbos found out when replacing.if thier is still a tag on it look at it A or B .auto was made to run 10psi and stick 15psi .any more info is no problem

You should read "fords book" a few more times before telling people that Turbo Coupes run great with the stock turbo making 30psi.

 

[racer 13x]

well needless to say i blew the headgasket now and reason i want low boost is because im going ice race this car, dont need too much power really for it. would it be right to say that maybe the head gasket was bad the whole time causing the problem? and now im thinking i may pick up another t-bird tonight or tomorrow for parts it complete runs and drives near perfect body but oh well parts car now

 

[Red_LX]

Yeah, kill another nice turbo coupe for a mustang....