terrible boost leak. need help
 

Hey guys, I have a terrible boost leak. And by terrible, I mean usually I'm boosting 8 lbs, but now I boost no more than 1.5 lbs, and that's in either third or fourth gear. Here is my set-up:

D15B7
arp head studs
stainless steal headgasket
RX-7 460cc injectors
hf manifold
big 16g
1g dsm bov
starion front mount
all necessary piping and oil lines.
tuned with an afc.

Here's a picture of the set-up if that helps any:
http://photos-a.ak.facebook.com/phot...98428_6258.jpg

I checked all the couplers three or four times. There are no cracks and everything is on snug. I checked the wastegate and it's working fine. When the car is off, the turbo spins very freely when spun by your hand. Checked the bov and all vacuum lines, still nothing. I'm beginning to think that maybe it's the intercooler. Any help or tips would be greatly appreciated. Thanks in advance.

-projecthatch92

Re: terrible boost leak. need help
 

exhaust leak?

Re: terrible boost leak. need help
 

take that dirty filter off the turbo and se eif that helps any, use a piece of screen with a clamp on it

Re: terrible boost leak. need help
 

no exhaust leak. i checked that too and i don't hear anything.

and with the filter, it's normally a really dark blue color. you think that just runnin with a screen might help?

Re: terrible boost leak. need help
 

Here's a more upclose picture if it helps any:

Attachment 23297

Re: terrible boost leak. need help
 

it's worth a shot, my first set up years back i thought i would be crafty and use a piece of a shirt as a filter and it wouldnt build any boost, took it off and put soem screen on it and i was boosting liek a champ.

Re: terrible boost leak. need help
 

Might seem like a pain in the ass but check all the couplers. Probably a tear. Or you can make a boost leak pump and spray soapy water on all the couplers. It will bubble where theres a hole. That would be the first thing I'd check. After the obvious thorough visual inspection.

Re: terrible boost leak. need help
 

i had a problem with about the same setup the gasket between the turbo and the adapter plate broke and i could barely hear that exhaust leak and it prevent my turbo from building boost

Re: terrible boost leak. need help
 

Same here. ------- hf mani + adapter plate + 14b = cracked the mani, blew the turbo @16psi spike.. Who knows how long the mani was cracked. Anyhow.. Use this as a excuse to take everything off and upgrade son.

Re: terrible boost leak. need help
 

Yeah, i already checked all the couplers multiple times and nothing. no cracks and everything is fit on there pretty snug.

i also do hate the hf manifold, i hate how low the manifold makes the turbo sit. i'm at school so i don't really have many tools, time, or the garage needed to check everything out. i'm going to upgrade to a log manifold of some sort in the near future though for sure.

i'll check what happens when i put a screen on the compressor housing. that might be a possibility. any other ideas out there?

Re: terrible boost leak. need help
 

do you guys at all think it could be the intercooler? possibly a leak somewhere in the intercooler?

Re: terrible boost leak. need help
 

maybe. fill the bathtub up with water and plug the ends and put the intercooler under water and see if you see any bubbles

Re: terrible boost leak. need help
 

good idea. i'm also beginning to think that it might be the wastegate. maybe the wastegate flap is either chipped or cracked, the only thing that i could think of that would only allow 1 lb of boost

Re: terrible boost leak. need help
 

try the soap and water test and take couplings off spray hairspray on them put them back on that fixed my boost leak

Re: terrible boost leak. need help
 

so the boost leak isn't as bad as i thought. i hit 6.5 lbs yesterday in 2nd gear at 5400 rpms, but that's the fastest i really drove it. i'm going to go out and cruise around today, see how much boost i can make. maybe the wastegate got stuck open, and then it repaired itself? we'll see what happens after today

Re: terrible boost leak. need help
 

is your wastegate closed shut really tight? You should be making full boost around 3k.

Re: terrible boost leak. need help
 

yea i know, that's what i need to check once i get the turbo off

Re: terrible boost leak. need help
 

that happened to me before, but it was stuck open because the flapper got stuck on the o2 housing when i bolted it up. felt hella dumb lol.

Re: terrible boost leak. need help
 

so i am officially confused, since today i hit 7.5 lbs, but couldnt hit that boost level at all after that

Re: terrible boost leak. need help
 

maybe the waste gate is getting stuck. If u boost that high and not at all after that then its probably not a constant leak (like a hole or somehting like that) so it would go to the component responsible for regulating the pressure. WG.

Re: terrible boost leak. need help
 

Take you car for a Boost Leak test, i found a few Boost leaks i didnt even know i had....

Re: terrible boost leak. need help
 

+1 Checking for rips/cracks isn't good enough. You need to pressurize the system from the turbo on. Build one of these and use it often.
http://vfaq.com/mods/ICtester.html


The other thing I can think of is the wastegate flapper sticking. I know its hard to see since you have the arm and actuator on the back side. There is a sleeve around where the flapper arm enters the hotside. I've had the sleeve work its way out part way. It causes the flapper to move with it, and uncover the wastegate port seading to a large internal exhaust leak that you can't hear. Very slow spool, and much lower boost than normal. It can move far enough to make the WG stick open or closed also. If you can get a mirror back there, see if that sleeve is close to flush with the hotside or not. It should be close.

Good luck.

Re: terrible boost leak. need help
 

Thats what i ment!

Re: terrible boost leak. need help
 

awesome, thanks for all your help guys. i'll check the wastegate hopefully this weekend!