Some of you may have seen my other thread but this is a slightly different question...I recently installed a Stewart Warner boost gauge and initially I think it was reading what I would have expected - boost spiked to 20psi and then falls off to about 15 by redline. I've had to uninstall and reinstall the gauge a few times and now it only spikes to about 17psi and falls all the way to 13psi by redline...is this really normal, or might I have a leak somewhere? I've got zip ties around all connections as tight as I could get them, and the car still seems to pull as hard as usual. I suppose I can't be 100% sure that it ever was reading 15-20psi, but I believe it was...ideas? If all the lines and connections look good, how can I check for a boost leak?

 

are you sure its 13 not 11 ? 11 is waste gate pressure and could mean leak. Make sure its 13 and not 11. I mean even with it being 13 its obviously not holding the correct preasure so I dunno you add anything lately? recheck you boost gauge hook ups. Tug on the hose's ALSO CHECK FOR HOLES you never know you might have snaged it on something and its releasing air. But in general it should spike around 20 and stay at 17ish.

And for book leak tester i have a special pressure hose made that fits on the turbo inlet and you pump it up and it has a gauge that shows preasure built up and when the presure it released.

 

A leak would have nothing to do with it going back to wastegate pressure.


Also, altitude is a factor with how much boost is produced and held.

 

Search for boost leak test and go to town with some dishsoap and water. I am sure you will find something

 

Well i dunno last time i had a problem with a leak it was only hitting 11psi which is wastegate presure so i assumed this is what would happen.