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Old 04-05-2012, 03:00 PM   #1
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Default barely building boost with ebay turbo

As the title says, i'm barely building any boost (no matter what i do with the MBC) with my 92 that has an ebay turbo with an internal wastegate. I've searched high and low for boost leaks and cant find any, although there is a slight hiss near the intake manifold. i can't remember if that hiss was always there or if it started around the same time as the boost drop. also it doesnt seem like a boost leak to me since it hits the same 18 in/hg of vacuum as before. i also haven't been able to spot any exhaust leaks before the turbo. i even changed the manifold to turbo gasket just to be safe, to no avail. there is no smoke from the tailpipe so i wonder... is my ebay turbo finally blown but the oil seals are ok? or is that not even possible?

EDIT: forgot to mention that the wastegate has two nipples on it. the upper one I can't blow into, the other blows right out by the rod with hardly any resistance. i can switch the vacuum line with my MBC on it from one to the other and it makes no difference whatsoever.
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Old 04-05-2012, 04:09 PM   #2
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what turbo is it?

for the wastegate, you use the top nipple, leave the bottom open.
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Old 04-05-2012, 04:13 PM   #3
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Do you have a leaking BOV or recirc valve?
Stationary checks wont work as you can not build boost without driving the car. (Or using anti-lag.)
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Old 04-05-2012, 04:23 PM   #4
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Quote:
Originally Posted by Braineack View Post
what turbo is it?

for the wastegate, you use the top nipple, leave the bottom open.
its a t04e turbo. a/r 60

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Do you have a leaking BOV or recirc valve?
Stationary checks wont work as you can not build boost without driving the car. (Or using anti-lag.)
i've tried tightening the BOV already, no luck :(

wouldnt vacuum reading be different though? i guess i'll have to build a boost leak tester... I was trying to avoid that.
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Old 04-05-2012, 04:27 PM   #5
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well it's not going to build boost on a 1.6L untill like 4.5K or above.
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Old 04-05-2012, 04:30 PM   #6
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well it's not going to build boost on a 1.6L untill like 4.5K or above.
it hit full boost well before 5.5 before, now i barely hit 1-2 psi in first at redline and maybe 3 psi in second at redline.
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Old 04-05-2012, 04:30 PM   #7
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its a t04e turbo. a/r 60



i've tried tightening the BOV already, no luck :(

wouldnt vacuum reading be different though? i guess i'll have to build a boost leak tester... I was trying to avoid that.
Is your vacuum measurement after the throttle? If yes, it will not be affected. MAF Idle would be affected though.
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Old 04-05-2012, 04:31 PM   #8
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bad coupler? bad turbo gasket?


what's full boost?
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Old 04-05-2012, 04:34 PM   #9
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Is your vacuum measurement after the throttle? If yes, it will not be affected. MAF Idle would be affected though.
ahh good point!

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bad coupler? bad turbo gasket?

what's full boost?
i've checked all the couplers, none have any tears/holes, and all of the pipes are in their couplers fully. and i tried changing the manifold to turbo gasket just to be safe even though it didnt seem to be leaking.

full boost is about 7 psi.
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Old 04-05-2012, 04:38 PM   #10
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Disconnect the MBC and run just WG.
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Old 04-05-2012, 04:41 PM   #11
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disconnect the mbc and run just wg.
lol wut?
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Old 04-05-2012, 04:44 PM   #12
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Disconnect the MBC and run just WG.
probably should have, but I haven't tried this yet. i'll give it a shot after work on the way to lowes to get stuff for a boost leak tester. best case scenario is i dont end up having to make one.
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Old 04-05-2012, 04:46 PM   #13
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What is the waste gate set as? Why are you using a MBC?
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Old 04-05-2012, 04:52 PM   #14
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What is the waste gate set as? Why are you using a MBC?
wastegate is 7 psi, i had bumped it up to 9 at one point but realized it was probably a bad idea and turned it down. it would have made more sense to just remove the MBC i know, but i wanted to have the option to turn it back up.
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Old 04-05-2012, 04:55 PM   #15
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While you're still chasing ---- bypass it completely... Less parts, less stuff to narrow down.
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Old 04-05-2012, 05:08 PM   #16
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While you're still chasing ---- bypass it completely... Less parts, less stuff to narrow down.
i'll give it a shot. it wont make it any worse, that's for sure.
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Old 04-05-2012, 05:18 PM   #17
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Are you sure that the waste gate is closed?

Did you have to clock the turbo to fit your car?

Have you moved the wastegate actuator?
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Old 04-05-2012, 05:21 PM   #18
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So there are no unusual hissing noises when you try to build boost in higher gears? When my CHRA failed, there was no oil smoke, just a light metallic noise and no boost...but that's with a dual bb turbo, not a chinkacharger.
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Old 04-05-2012, 05:21 PM   #19
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Are you sure that the waste gate is closed?

Did you have to clock the turbo to fit your car?

Have you moved the wastegate actuator?
i havn't pulled the downpipe off to check, but I have moved the flapper with the rod disconnected and it moves freely. also i can pull the rod and it has plenty of resistance.

EDIT: now that i think about it, the rod was pulled out a little bit with the flapper as closed as it would go. i figured that was supposed to be like that for more tension on the flapper making sure it was closed. was i right with my assumption or is my wastegate most likely not closing all the way?
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Old 04-05-2012, 05:22 PM   #20
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So there are no unusual hissing noises when you try to build boost in higher gears? When my CHRA failed, there was no oil smoke, just a light metallic noise and no boost...but that's with a dual bb turbo, not a chinkacharger.
not that i can hear.
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