lag, then boost drops off= teh suck
 

so i know alot of my problem is that i'm usin way too small of a turbo for my set up, but there's still one thing that i can't figure out. i've got a .42 .48 on my b16 runnin uber w/ 450's, bmc log mani, 2.5 mandrel dp w/ 2.5 all the way back, 2.5 mandrel charge pipe, and turbo xs mbc. the damn thing doens't hit full spool until almost 4500 rpms!!! then almost right after it fully spools, the psi starts to drop as well. i'm workin on that though. is all my lag comin from that mani, or what?

Re: lag, then boost drops off= teh suck
 

boost leaks.

Re: lag, then boost drops off= teh suck
 

all couplers were tightened w/ a socket, bov won't leak (hks ssq). i dk where else to look

Re: lag, then boost drops off= teh suck
 

could be exhaust leaks too.

also loose vacuum hoses. split in a coupler that you're not noticing.

Re: lag, then boost drops off= teh suck
 

I wish I could help but I have the same problem with a similar setup but I have a b18.mines spools at like 3500 and dies at 5500.I thought with the boost controller it would have held boost longer but thats not happening.I dont think its the header,I have the same one,same turbo but running 21/4 exhaust and piping.Ive checked for leaks but I find nothing.I wished I would have kept my t25 setup cause kicked in at 2500 and died at 5500.if u figure it out post what it was so that I could try the same thing

Re: lag, then boost drops off= teh suck
 

i had a problem similar to that a while back when my wastegate was opening too far. id spool up, hold it for a while, then it'd all blow out and id have to start spoolin up all over again. shimmed the gate a bit and it went away.

Re: lag, then boost drops off= teh suck
 

i'm runnin external

Re: lag, then boost drops off= teh suck
 

Did you always have this problem ?
Gasket between mani and turbo ?

Fook is right does sound like a leak.
You using a mbc btw ?

Re: lag, then boost drops off= teh suck
 

yeah, it's had this prob since i got it runnin w/ the turbo. yes, i'm usin a turbo xs "high performance" mbc, and yeah i have a gasket between the mani and turbo. i dk why my couplers would be leakin since their less than a month old from stealthmode, so i'm leanin twards exhaust leak. i'm gonna pull the mani off tomorrow and see what's up. anything else i should look for? cause this really sucks. my car's slow as balls

Re: lag, then boost drops off= teh suck
 

1.) Build a proper boost leak tester, pressure test your entire intake.