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Discussion Starter #1
okay just wondering...doing the wastegate adjustment mod..with lets say two turns..would this hold 15 psi till redline??...someone says that's what it does for him...but than he also cobb stage 2..but he says the wastegate adjustment is what really does it...is this possible?? i thought the size of our turbo was what would not let it hold all that psi until redline..thanks
 

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Discussion Starter #3
seen the thread...says nothing about how it holds boost till redline..i wanted to know if that was possible..instead of trying 2 be cool with your 250 posts or whatever..since you did the mod..why cant you simply answer the question of how it holds boost at 6k rpm and higher??
 

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sorry i came off as trying to be cool or whatever, but if you wanted to know why dont you just ask in that thread instead of a new one? seems better to me. With me, ive had a little trouble with that as i havent seen 15 psi to redline. With one turn i held 13.5 or there abouts to redline on stock and no word yet with the Accessport stage 2 since i have to flash it again. But awhile ago i was messin around with it and with like 2 full turns 4th and 5th gear were pulsating, goin up to 16 or 17 and then droppin down to like 12 or 13 then back up. So im guessing it depends on your setup. Just try it, worse thatll happen is youll tighten it to much like i did once and under full throttle your wastegate will leak and make a loud ssshhhh noise.
 

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Discussion Starter #5
GotRice7169 said:
sorry i came off as trying to be cool or whatever, but if you wanted to know why dont you just ask in that thread instead of a new one? seems better to me. With me, ive had a little trouble with that as i havent seen 15 psi to redline. With one turn i held 13.5 or there abouts to redline on stock and no word yet with the Accessport stage 2 since i have to flash it again. But awhile ago i was messin around with it and with like 2 full turns 4th and 5th gear were pulsating, goin up to 16 or 17 and then droppin down to like 12 or 13 then back up. So im guessing it depends on your setup. Just try it, worse thatll happen is youll tighten it to much like i did once and under full throttle your wastegate will leak and make a loud ssshhhh noise.
yeah ...i might as well try...thanks
 

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I'm not sure what gotrice is seeing, but I've never seen a stock turbo'ed car hold 15psi to redline (as in 7k rpms). Mine drops to ~12 and I have up/down pipes. Someone on here (TypeC?) wired the wastegate shut and it still wouldn't hold that much boost to redline. Turbo simply isn't big enough.

Anyway, my car does not hold 15psi at redline with ~3 turns adjustment.

VV
 

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I have Cobb AP Stage 2 and 2.5 turns on the wastegate.. it does not hold max boost to redline, but does seem to build boost a little faster and hold a little longer. But not not to redline, though I don't flirt with the redline very often as it seems shifting at at 6300-6500rpm feels better.
 

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GotRice7169 said:
well like i said i never saw 15 to redline, only 13.5. But if you wired the wastegat shut wouldnt the boost just continue to rise?
it's not the wastegate that's keeping the stock blower from boosting to redline, it just doesn't have the capability to create and more pressure.

it's too small. you can't squeeze water from a rock! :)

wiring it shut will only overheat it and the intake charge.

dR
 

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No. A turbo will only flow so much cfm. With the wastegate closed, the turbo is spinning as fast as it can spin. Our stock turbo can't fill 2.0L at 7000rpm with 15 lbs of boost. Consider the turbo putting out a fixed amount of flow at it's "max velocity". When each piston draws in .5L of air per revolution, more revolutions mean more air at any given time. That's why you can hit 20psi in the midrange with the stock turbo, but only ~13 or so at redline.

VV

GotRice7169 said:
well like i said i never saw 15 to redline, only 13.5. But if you wired the wastegat shut wouldnt the boost just continue to rise?
 

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Ok i get it, becuase when you hit max velocity on the turbo the engine isnt moving at its max velocity so you hit your target boost but then the engine gets faster but the turbo wheel still spins the same and can only get in a certain amount of air before the intake valve closes because they are openeing and closing faster at redline than at 4k or so.
 

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Yep :)

VV

GotRice7169 said:
Ok i get it, becuase when you hit max velocity on the turbo the engine isnt moving at its max velocity so you hit your target boost but then the engine gets faster but the turbo wheel still spins the same and can only get in a certain amount of air before the intake valve closes because they are openeing and closing faster at redline than at 4k or so.
 

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interesting, my peak is 16.4, and rarely do does the car drop below 15.1psi up at 7k. The lowest ive read at 7 is 14.7 Still have the 3rd cat in place ;)
 

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Discussion Starter #15
MidnightFLAT4 said:
interesting, my peak is 16.4, and rarely do does the car drop below 15.1psi up at 7k. The lowest ive read at 7 is 14.7 Still have the 3rd cat in place ;)

everything makes sense than someone comes in and says something like this and i'm all confused again
 

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Every car is different, but his situation is the outlier among what has been posted on the forums.

What guage was this reported on? Stock intercooler?

VV

AwdTurboWrx said:
everything makes sense than someone comes in and says something like this and i'm all confused again
 

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MidnightFLAT4 said:
interesting, my peak is 16.4, and rarely do does the car drop below 15.1psi up at 7k. The lowest ive read at 7 is 14.7 Still have the 3rd cat in place ;)

Same result here.I get 16lbs peak and 15 lbs all the way to redline. Got bosal with 3rd cat gutted and wastegate 2 turns
 

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Discussion Starter #18
xdriven2004 said:
Same result here.I get 16lbs peak and 15 lbs all the way to redline. Got bosal with 3rd cat gutted and wastegate 2 turns
i already boost 16 psi with mbc...do you guys think i should still do the wastgate 2 turns??..also xdriven do you have any sort of ecu management?
 

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AWDturbowrx..I am using AP and using the stage 2 hwg map
Ride5000...I understand what you have stated ,but I get it in 1st (which I can understand because the rpm climbs so qiuck and the duration of the gear doesn't give it time enough to level out the pressure) I have seen it occur in all the gears except fifth I've never been at that rpm in that gear.Now granted this DOES NOT happen everytime I go to redline,just like I see 16.5 when I hit boost sometimes I will only see 14.7 but it does happen

could the others that getting full boost at redline elaborate on this also so see what gear the fullboost /redline is occuring at?
 
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