Opposite of boost creep? 10psi@4000rpm and 6psi@7000?

[Verticaljump1]

I was having spool problems, so I swapped wastegates and now my car on stock exhaust and manifold spools to 10-11psi at 4000rpm or less, the problem is, in first gear it spools to 10psi by 4000 but the boost drops to about 6 psi by 7000rpm, is this a symptom of boost leak? I'm pretty sure my whole intake piping route is sealed but this makes me wonder. I run a screen over the turbo for now (testing), so could it be that the turbo doesn't suck in enough air in the higher rpms and boost simultaneously drops. it drops about 1.3-1.5psi per 1000rpm gain after 4000, i.e., 4000~10psi, 5000~8.5psi, 6000~7.0psi. In 2nd gear, the boost spools to 10psi by 4000rpm and then levels off to about 8 all the way to 7500, I have no idea what could be wrong. I just swapped wastegates so I don't think it has anything to do with the exhaust side of things, or does it? Any help you guys provide would be great cuz this is irritating . I've got 2.5" uicp set for blow thru and a small 16g turbo, other than that the car is stock. Thanks guys, have a good one~Brandon.

 

[vtracer20]

well if ur loosing boost at higher rpms then deff do a boost leak test...mine kinda does the same but i still havn't done the boost leak test...no time or warm weather

 

[Verticaljump1]

It's gotta be something that has to do with the intake side of thigns, because I even unhooked the wastegate hose and floored it, no boost past 10psi and it dropped. I've got a supra smic that I'm installing pretty soon here so if the intercooler has a leak I can fix it that way, and I know it's not coming from the uicp because mine's is a hard pipe with a tightly secured gm maf. My only guesses could be the lower intercooler pipe (stock), non-sealed bov flange, intercooler, or TB elbow leak (from tb elbow-tb). What do you guys think? Sorry for asking this as a common question but I thought it might've been the exhaust side so I didn't know for sure. The car seemed to hold boost fine earlier, so I think it might be the compressor outlet elbow-licp connection because I recently had to remove it and retighten it, and the clamp is on a little crooked, other than that i have no clue. Thanks~Brandon.

 

[zross1]

It's gotta be something that has to do with the intake side of thigns, because I even unhooked the wastegate hose and floored it, no boost past 10psi and it dropped. I've got a supra smic that I'm installing pretty soon here so if the intercooler has a leak I can fix it that way, and I know it's not coming from the uicp because mine's is a hard pipe with a tightly secured gm maf. My only guesses could be the lower intercooler pipe (stock), non-sealed bov flange, intercooler, or TB elbow leak (from tb elbow-tb). What do you guys think? Sorry for asking this as a common question but I thought it might've been the exhaust side so I didn't know for sure. The car seemed to hold boost fine earlier, so I think it might be the compressor outlet elbow-licp connection because I recently had to remove it and retighten it, and the clamp is on a little crooked, other than that i have no clue. Thanks~Brandon.

It's a boost leak. There have been many times that I thought all my intake/intercooler piping was secure, but after a boost leak test, I found out it wasn't the case. It's a simple test to do and easy to make a tester. Just do it and I'm sure you'll find a leak or two. And since you said you have a "non sealed bov flange" you might want to start there. Good luck.