Okay, last question for today I promise!

Finally got around to installing a boost gauge in my car, several months after buying it. I can already tell the boost pattern is ALL screwed up, but let me start with the first thing...

In my DSM, when you're accelerating at partial throttle, keeping the pedal in the same position at a point where boost begins to build, the car accelerates and boost keeps building higher and higher.

In my FD, I accelerate with the pedal at the sweet spot and it boosts, say up to 5psi, and keeps accelerating. As the car continues to accelerate, the boost falls off, back to 0 and below, even as the RPM goes up and up. This is very counter to what I've seen before, and to me it screams boost leak..

Is this normal behavior for an FD that's bone stock with DP and catback, stock cat. It feels wrong, once you're accelerating under boost, it should make more boost up to the wastegate limit.. But what do I know with all those wacky solenoids and stuff..

FWIW when it goes to transition to 10psi, the boost also falls off briefly. I definately do not see an 8-10-8 pattern, and I'm really not sure what it's doing yet. Going to have to find a quiet road and test it out later on.

 

Go find out what your boost pattern is. Very hard to diagnose problems without it.

 

There is an order of importance (and simplicity) in figuring out boost problems.

Definitely the boost leak is number 1. Check all the couplers.

Second is vacuum and pressure. Pull off the hose to the vacuum chamber and pressure chamber after driving and boosting - each should vent whoosh of air. Or, just buy a set of the viton check valves and install them.

Start with these.