Forced Induction Custom FI Setup Questions

lag, then boost drops off= teh suck

Thread Tools
 
Search this Thread
 
Old 05-29-2005, 05:35 PM
  #1  
1.5 BAR
Thread Starter
 
darksol2005's Avatar
 
Join Date: Nov 2004
Posts: 1,065
Default 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?
darksol2005 is offline  
Old 05-29-2005, 05:39 PM
  #2  
3.0 BAR
 
FooK's Avatar
 
Join Date: Apr 2004
Posts: 9,800
Default Re: lag, then boost drops off= teh suck

boost leaks.
FooK is offline  
Old 05-29-2005, 05:47 PM
  #3  
1.5 BAR
Thread Starter
 
darksol2005's Avatar
 
Join Date: Nov 2004
Posts: 1,065
Default 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
darksol2005 is offline  
Old 05-29-2005, 06:33 PM
  #4  
3.0 BAR
 
FooK's Avatar
 
Join Date: Apr 2004
Posts: 9,800
Default Re: lag, then boost drops off= teh suck

Originally Posted by darksol2005
all couplers were tightened w/ a socket, bov won't leak (hks ssq). i dk where else to look
could be exhaust leaks too.

also loose vacuum hoses. split in a coupler that you're not noticing.
FooK is offline  
Old 05-29-2005, 08:31 PM
  #5  
0.5 BAR
 
silverac's Avatar
 
Join Date: Sep 2004
Posts: 191
Default 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
silverac is offline  
Old 05-29-2005, 10:01 PM
  #6  
3.0 BAR
 
FooK's Avatar
 
Join Date: Apr 2004
Posts: 9,800
Default Re: lag, then boost drops off= teh suck

Originally Posted by silverac
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
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.
FooK is offline  
Old 05-30-2005, 12:04 AM
  #7  
1.5 BAR
Thread Starter
 
darksol2005's Avatar
 
Join Date: Nov 2004
Posts: 1,065
Default Re: lag, then boost drops off= teh suck

i'm runnin external
darksol2005 is offline  
Old 05-30-2005, 12:23 AM
  #8  
3.0 BAR
 
D16Y8-Z6's Avatar
 
Join Date: Feb 2004
Posts: 1,558
Default Re: lag, then boost drops off= teh suck

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

**** is right does sound like a leak.
You using a mbc btw ?
D16Y8-Z6 is offline  
Old 05-30-2005, 12:27 AM
  #9  
1.5 BAR
Thread Starter
 
darksol2005's Avatar
 
Join Date: Nov 2004
Posts: 1,065
Default 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 *****
darksol2005 is offline  
Old 05-30-2005, 03:23 AM
  #10  
1.0 BAR
 
Koby's Avatar
 
Join Date: Sep 2004
Posts: 306
Default Re: lag, then boost drops off= teh suck

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


Quick Reply: lag, then boost drops off= teh suck



All times are GMT -5. The time now is 02:19 PM.