I just finished installing the APS TT on my 06 last night. Took it for a spin and was only getting 2 psi max on my autometer boost gauge and my zeitronix display. Basically, the car drove just like stock. I'm positive it's not a boost leak because I didn't hear any unusual sounds indicating a leak. I think my actuators are messed up and not holding boost.

Any ideas?

 

Check boost selonoid wiring.

 

Shouldn't the turbos boost to at least the boost rating of the actuator springs regardless of the solenoid? I disconnected the vacuum line from the solenoid to the actuators and I still didn't get any more than 2 psi.

 

you got a leak

 

Wouldn't a boost leak of that size be very audible?

 

it wouldn't have to be. especially if it was under the car or in front.

 

Double check all charge pipe couplings...

 

also check your wastegate

 

I hope you guys are right and it's only a leak. I'll check all the couplings tonight.

 

I would bet you don't have your solenoid properly wired. It is definitely a possibility that you have a leak, so also check for that.

if you are running cats and/or stock exhaust, spring pressure would be very low. that said, 2 lbs seems abnormally low.

 

reason why is best to let a pro take care if this kinda stuff

 

I'm not sure how he could have the solenoids wired wrong to cause this problem. If he had it wired wrong and they were always opened, he would get whatever boost the wastegate spring was set to, and if he had them wired wrong and they were never open, he'd get as much boost as the turbo could give, since the wastegate would NEVER open. Anything else would be something in between those extremes.

So unless the springs are set for 2psi boost, which seems very unlikely, this isn't it, right?

-E

 

I think he doesn't have the boost solenoid wired properly. Maybe set to ground instead of power, maybe something else entirely. With a restrictive exhaust and cats, spring pressure might only be a measily couple pounds.

 

Check the intercooler couplers, they can be hard to get just right because they are so short. One could have popped off.

 

I had the same problem after I got my stillen radiator installed and it turned out that one of the couplers got loose.

Check all the couplers

 

That's exactly what I think as well. I disconnected the vacuum line to the boost solenoid so whether it's wired correct or not wouldn't matter. Boost would be dependent on the wastegate springs without the solenoid.

 

I have APS test pipes and HKS dual exhaust. I definitely have enough flow for more than 2 lbs of boost.

 

no it doesn't have to be.

 

I checked all the couplers and they're all connected and tight so no obvious leaks. I visually inspected the wastegate actuators and they look fine. I pulled on the actuator arms and they're tight so the springs aren't broken. I checked the blow off valve and the valve is shut tight so no leak there. I'm not sure what else to check at this point.

 

Man... Do you slowly get up to 2psi of boost at high rpms WOT, or does it go up to 2PSI really early and then just stay there across the board? I'd imagine that if you get the 2psi really easily and then it never climbs higher, it would have to be a leak on the intake side somewhere... and if it takes forever to climb up to 2psi, it would have to be a problem in the exhaust side somewhere... I have to lean towards wastegate issues, but dunno!

-E