2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

weird boost

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Old Dec 27, 2003 | 12:08 PM
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From: MO
weird boost

when im boosting when the gauge hits 0 it goes from 0 to 8 in like 2 seconds.. way too fast, almost like its not boosting, and then when it get to 8 itll start building up to 10 like normal.. but from 0 to 8 doesnt feel normal and it goes very fast.. i dunno if this has anything to do with it.. and i dunno what half of this stuff is..

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Old Dec 27, 2003 | 01:08 PM
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From: Hood River oregon
That, my friend, is the Home Depot BOV mod. And probably has nothing to do with the rate at which you build boost.

So you dont like the fact that you build boost so fast?
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Old Dec 27, 2003 | 08:44 PM
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From: MO
it doesnt feel like i am building the boost though.. it just kinda goes there without the HP on the butt dyno.. until 8 psi.. it skips to 8 psi really fast.. and then slows down to 10.. almost too fast. i dont get it. and whats the black thing with the vaccuum line going in it for?
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Old Dec 27, 2003 | 08:55 PM
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HAHAHAHAHAHAHAHAHAHAHHAHAHAHAHAH black thing? hahahaahahahahaha
sorry....
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Old Dec 27, 2003 | 09:53 PM
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From: mmsports.org
teehee... i recognize that
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Old Dec 27, 2003 | 10:10 PM
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From: Bellevue
u shittin me?
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Old Dec 27, 2003 | 10:18 PM
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From: MO
anyone have an answer besides "hahahaha"? on maybe why my boost is doing that.. and being helpful instead of jerkoffs.. please people.. grow up. im here to learn about my car not to listen to childish bs. pfft.
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Old Dec 27, 2003 | 10:24 PM
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From: Bellevue
I believe that is your BOV = Blow Off Valve
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Old Dec 27, 2003 | 10:42 PM
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From: MO
i know crap about BOV's.. why is a vacuum line running to it.. and thats not even really my first question.. no one has any idea about why im boosting like that? it happened after i redid that whole BOV hose.. maybe its coincidence.. but no ideas?
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Old Dec 27, 2003 | 10:49 PM
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From: Bellevue
do u have ur stock boost gauge or an aftermarket one? maybe ur doing a little bit of combustion in ur turbo IE: gas igniting inside the chamber making it spin up real fast...some racers do this to defeat lag...and maybe ur car is running a little rich with some gas escaping and igniting? just a guess. the vacuum i think(not to sure since i dont have a turbo) hooks up the the Intake manifold and toggles to release the boost when the tottle is closed... idk really just some guesses
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Old Dec 27, 2003 | 10:59 PM
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From: MO
"Autometer Phantom Gauges (A/F, Boost)" in my sig.. gas igniting in the turbo? interesting. i did just rewire my fuel pump but im not running that rich. that makes sense about the vacuum hose though.
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Old Dec 27, 2003 | 11:04 PM
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From: Bellevue
yea some of the racers do it to get rid of turbo lag. My friend works at Sublime racing in nebraska and he said they sometimes do this to the cars but it really kills the turbos after awhile...this might or might not be your case...like i said i dont have a turbo so i dont know...sorry if it didnt help
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Old Dec 27, 2003 | 11:46 PM
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From: MO
is the BOV directional? if so what would happen if it was on the wrong way?
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Old Dec 27, 2003 | 11:51 PM
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From: MO
problem with the wastegate maybe?
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Old Dec 28, 2003 | 01:00 AM
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Okay okay...

Imloggedin,

The Vacuum hose to your BOV is SUPPOSED to be there. Thats part of the mechanism.

All the rest of the previous BS in this post is an attempt to get your goat. And it appears to be working.
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Old Dec 28, 2003 | 03:07 AM
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From: Iowa
yeah and uh......damn...the moment's past...
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Old Dec 28, 2003 | 05:53 AM
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From: FORT WORTH, TEXAS,USA
Can you take another picture, but this time just a little further away so I can see just where everything is going?
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Old Dec 28, 2003 | 08:35 AM
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From: MO
yah ill do it today
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Old Dec 28, 2003 | 12:22 PM
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Originally posted by J-Rat
Okay okay...

Imloggedin,

The Vacuum hose to your BOV is SUPPOSED to be there. Thats part of the mechanism.

All the rest of the previous BS in this post is an attempt to get your goat. And it appears to be working.
WTF? I was just trying to throw some suggestions...so dont be callin my ****, BS! Plus i dont want his goat...i want his cow! I didnt say that my suggestions were right and if you would have read that i said " i know nothing cuz i dont have a turbo" therefore cant really call that BS
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Old Dec 28, 2003 | 12:36 PM
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For a home built BOV - that's actually not bad.
The previous owner may have put in an FCD also.

I'm not sure of your location, but turbo's get real happy in cold, sea level air.

What you describe sounds pretty normal at low elevation & near freezing temps.
Boost will come up early, but power will still be low until the torque rolls in at ~3K.
Then - O yea!!

Last edited by SureShot; Dec 28, 2003 at 12:42 PM.
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Old Dec 28, 2003 | 01:43 PM
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From: MO
im in missouri.. and yah the guy i bought it from is pretty good... i just dont know what some of this stuff is thats interesting though.. its been really cold out, im not sure why it would spool up without the feeling of it till a certain PSI though.. ive been thinkin about it all night and dont understand. if you have pressure you have pressure. another weird thing is.. u can be going 20 mph and when u put your foot on the gas and SLOWLY get fast.. as soon as the needle hits 0 PSI, it jumps right up to 5 then hesitates a split second and jumps right up to 7-8.. even though you are still accelerating slowly.. after 7 it picks up like a turbo does.. within 0-7 its a little boost but not like it used to.
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Old Dec 28, 2003 | 01:43 PM
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Originally posted by harjms
WTF? I was just trying to throw some suggestions...so dont be callin my ****, BS! Plus i dont want his goat...i want his cow! I didnt say that my suggestions were right and if you would have read that i said " i know nothing cuz i dont have a turbo" therefore cant really call that BS

.....
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Old Dec 28, 2003 | 03:26 PM
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hmm... You have an 87 t2
stock boost should be at 5.5psi.
I would still say that you have boost creep.
The stock wastegate opens at 5.5psi. You are reading slower boost past 8psi probably due to error in gauge reading be it the response time of your equipment or driver reading error (not an insult... we aren't robots) Once the wastegate opens you have boost creep and that's why it slowly builds up from the said 8 psi to 10 psi. What you should do to have a linear boost pattern/build up is to get a boost controller... at least a mechanical ball and spring type Boost controller and not a bleed valve mechanical boost controller.

But since you already have boost creep... you have to be careful.. you also need to port your wastegate out to prevent from overboosting in higher gears.
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Old Dec 28, 2003 | 03:28 PM
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I just reread your sig... If I'm not mistaken I'm pretty sure you have a bleed type BC. If you do have a ball and spring... it's probably set at 8 psi and you need to reset it to 10psi.
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