can't lower the boost.

[TURBOPOWERED68]

i was trying to make some tuning adjustments on my car but i couldn't get the boost bellow 22# at WOT at the top of 3rd.
the waste gate is old as heck and never had this problem before.
i am going to try and work the waste gate diaphragm with a vacuum pump to see if works or not.
BUT
even though the diaphragm is in question the spring should have NOT held that much boost especially considering how loose i had it (one more half turn and the waste gate would have been held open).

what do you guys think???
waste gate hole is too small???
waste gate binding some how??

 

[daves87gn]

i was trying to make some tuning adjustments on my car but i couldn't get the boost bellow 22# at WOT at the top of 3rd.
the waste gate is old as heck and never had this problem before.
i am going to try and work the waste gate diaphragm with a vacuum pump to see if works or not.
BUT
even though the diaphragm is in question the spring should have NOT held that much boost especially considering how loose i had it (one more half turn and the waste gate would have been held open).

what do you guys think???
waste gate hole is too small???
waste gate binding some how??

what changed between then and now? new turbo, fixed cracked or leaking header?

 

[HUMBLE-U2]

sounds like a stuck wastegate puck. pull the wg clip off and see if you can move the wastegate vavle open and closed if not thats it.most times the boost will get far higher than 22lbs than very bad things start to happen oh my! if you have recently added a billet wheel turbo the wg hole will need to be ported. you can port while on the car. much easier on a work bench good luck.

 

[TURBOPOWERED68]

what changed between then and now? new turbo, fixed cracked or leaking header?

Fixed 3 cracks on the headers (2 whir big)
same turbo
bigger exhaust valves and bowl work
and roller 206/206 cam
also went from cheap summit turbo mufflers to Racebullets.

sounds like a stuck wastegate puck. pull the wg clip off and see if you can move the wastegate vavle open and closed if not thats it.most times the boost will get far higher than 22lbs than very bad things start to happen oh my! if you have recently added a billet wheel turbo the wg hole will need to be ported. you can port while on the car. much easier on a work bench good luck.

the puck moves freely
and i could pull the actuator and the only thing i feel is the spring resistance.



the other thing that got my attention was that i shortened the actuator rod by 2 FULL turns and the boost didn't change at all???
also in the PL file it shows the boost low and climbing.

 

[TurboBuRick]

Loosen the wg rod so you barely have to pull it to get it on the arm. Run the boost line directly to the wg. If it still over boosts, you need to port the hole.

HTH

 

[TURBOPOWERED68]

Loosen the wg rod so you barely have to pull it to get it on the arm. Run the boost line directly to the wg. If it still over boosts, you need to port the hole.

HTH

i think i am at that point already i'll double check today if i can escape the boss (wife):biggrin:

thanks for the reply guys.