Loss in boost pressure.

Howling Mad

Active Member
Aug 23, 2010
So I've been running around 23psi in my car. Yesterday it run awesome and pulled hard. Today I noticed that I was only pushing 19-20psi and it obviously doesn't pull as hard. The car runs fine and feels the same until I get to WOT. I haven't made any changes. Wondering what I should start checking first. Thanks guys.
Vacuum leaks ? Also temperature does play a factor if u ever notice at night when it's cooler the boost pressure will rise . What do u use for boost control ?
Fuel pressure seemed to rise consistently with boost but I will make sure. I'll check for vacuum leaks but would it run different at idle and part throttle if there were? I'm using a Lorenz Racing boost controller. Hopefully it's not a cracked header, they're new TA headers. Thanks for the replies.
Yeah fracked, cracked, whacked!!!! Danged I-phone.

Any pre-turbo exhaust leaks could be the culprit, not necessarily cracked headers.
Sometimes it can be inexplicable. I had my wastegate set on 20psi (stock adjustable) and it decided to go back to 16psi somehow. I gave it 3 turns and back to 20psi. It might be tired, dunno.
Sounds like a boost leak. I'd check all your turbo and header gaskets, along with the couplers. If good, then retighten em. Also, with a stethoscope at idle, I'd listen all around your downpipe, headers, and crossover. Any v band clamps? If so, those things are notorious for leaking over time. Best to replace those with welds where possible. How old's your downpipe, they can go bad too. The actuator's diaphragm could even be wearing out.

I actually had the same boost issue last winter. It ended up being a blown out turbo to header gasket. After replacing it, my boost went right back to normal.
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Everything on the turbo side of things only have 2000 miles on them. I'll start checking the intercooler piping couplers. I didn't notice an exhaust leak anywhere but that doesn't mean it's not there