Hello, having an issue with the 7 in boost. Car runs healthy, 440-450mmhg at idle, but at WOT there is a loud escaping air noise, definitely a boost leak. The car doesn't get to more than 6psi each time. Any good place to start?

 

what series of car are you referring to?
..and you can build a boost leak tester..(search that).

You can basically get a Abs PIPE CAP and a tire valve drilled into it.Attach to the inlet.
Pump about 10 psi into the system and find the leak.
By the way a good air compressor is preferred.You will be there all day with a portable tire pump and besides they are too noisy.(been there done that!)

 

Fd rx7, and thanks, I'll have to look up how to make one of those!

 

Before you go to the trouble, check all of the soft couplers along the intake route. Particularly the coupler from your 'Y' pipe to the cross-over pipe. (shown at the top of the picture in this link: http://www.autosportracetech.com/RX-...erOverview.htm )
The stock one is rubber and often fails with age and heat. And since it's right over the turbos, it gets a lot of the latter.
A good quality silicone coupler is usually the ticket. If that doesn't solve the problem, information in the link under trouble-shooting should.
ALOT of good info in the 3rd Gen. FAQs.

 

Replaced both the couplers at the y-pipe, as well as the one on top, nearest the intercooler. No luck. Also, I've read that the y-pipe itself can crack from heat. It appears though, that the previous owner had already replaced the y-pipe with metal. I'll attach a picture. Am I correct?

 

No. That appears to be the stock 'Y' Pipe. The coupler that goes on top of that is the one most prone to failure.
In the rear leg of the 'Y' pipe there is a large thick 'O' ring but I've never had trouble with mine. What makes you think that 'Y' pipe has been replaced?
There's also a small thin 'O' ring in a groove on the throttle-body that seals the intake elbow to it.
Keep checking the intake tract.

 

Haha it may sound stupid, but it just looked like it was metal to me. The coupler that you're referring to has been replaced, and the issue remains. I still have the stock plastic/rubber piping through the rest of the track, so any of those could be cracked/split as well. Looking around to find a shop or friend in my area that can test boost leaks.

 

Have you checked your inlet pipes? Especially the primary turbo rubber hose? Maybe it has split/has a nice hole in it.

 

Checked the intake piping. Also tested for leaks on the piping after the turbos. Nothing. I'm now thinking bad bov, wastegate actuator, or double throttle. Am I thinking in the right direction?

 

I guess my tester didn't work very well because I'm pretty sure this is the answer to my problems. Nice sized rip right now the intercooler piping

 

I think you found the problem..lol!