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Discussion Starter #1
my car won't hold any boost. with the wastegate having a 10lb spring and the boost controller off.. it only makes a max of 6 lbs. with the boost controller on.. it peaks at about 11.3 lbs. now with the boost controller off and the wastegate disconnected... it still only make 11.3 lbs.

we've already checked the boost pressure and its fine. compression tested and its fine. examined turbo, compressor, manifold, and exhaust for cracks and can't find anything significant enough to lose 4-5lbs of boost. he's in the process of checking cam timing.. but other than that.. we're out of ideas..

anybody ever had this issue? or have any idea what could be causing this?? after all the money i've dumped into this project, 11.3 lbs on a maxed out boost controller with a 10 lbs spring is NOT cutting it.
 

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sounds like you have a 6 lb spring. Or you wastegate is leaking. If it spools slowly to 6 then you might have a leak of some sort.
 

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Discussion Starter #3
we also noticed that the wastegate isn't opening till very high in the rpms....
 

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check your vacume lines put zip ties on ALL fittings. check your vacume lines to the boost controllers, maybe reversed.
 

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Discussion Starter #5
wastegate was taken apart and verified 10lb spring.
 

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Check your boost gauge. Try another one. BUt most importantly TIE- WRAP EVERY VACUME LINE AND RUBBER LINE!! Dont forget the one on the blow off valve!!!
 

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With no vaccum lines he boosts to 11 so thats not the problem, actually it could be I wont assume you checked that ;)
 

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What is your target boost?
 

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Your car is at Batlground right? I saw it when i went up there with Das to get my car dyno'd. Hope it works out for ya.
 

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Discussion Starter #10
ok.. they might have found the problem.. there is alot of black residue around the where the manifold connects to the block.. they are going to check for leaks in that area and if necessary, take off the manifold and resurface it. hope that solves it.. meanwhile, they are going to take off the turbo and send it in to make sure it hasn't gone bad even though there is no shaft play and no visible signs of issues with it.

as for my boost goals.. i'd like to be able to get into the 400's on pump.


and yeah, thats my IS at batlground... and thanks.. how's yours turning out? did you fix the compression issue yet?
 

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Make sure you tighten the manifold from the inside bolts first and work you way outside.
 

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Discussion Starter #13
nine.. i have another motor in my garage taken apart... if you need the short block to build with gte internals... im sure we could work something out... lmk
 

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Lexotic Concepts said:
nine.. i have another motor in my garage taken apart... if you need the short block to build with gte internals... im sure we could work something out... lmk

Yah I told him about your extra motor ;)
 

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Discussion Starter #15
thanks das... i really do hope this grime they found around the manifold is the cause... i just have no idea what else could cause a loss of 4-5 lbs of boost...
 

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manifold leaks are very obvious. They sound completely different.
 

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if one had a leak in the intercooler itself, could that cause such a high loss of boost? I'm not talking about where the piping hooks up to the IC, but the IC itself?
 

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rllinghardis300 said:
if one had a leak in the intercooler itself, could that cause such a high loss of boost? I'm not talking about where the piping hooks up to the IC, but the IC itself?
That can be pretty severe.
 

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rllinghardis300 said:
if one had a leak in the intercooler itself, could that cause such a high loss of boost? I'm not talking about where the piping hooks up to the IC, but the IC itself?

Yes, do you see any black crap on the I/C. Easy way is to pull it and put in a tank of water. mark the leak and get it fixed. But the leak would have to be pretty big. Look at the wastegate or couplers
 

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I think my wastegate spring sticks...sometimes I can boost to 12psi at partial throttle sometimes I can only boost to 5psi partial throttle.

check the free play on the wastegate and again check all your Couplers and vacuum lines.
 
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