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Discussion Starter #1
I know they can sike to 23-24psi....but what's the highest boost that anyone has seen (no NOS) their stock turbos hold to redline...
 

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I can hold the boost I set until redline...

If I tune it to 18psi, It holds 18psi to redline

I have an auto and NO FMIC.....
 
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Discussion Starter #3
2bad4U said:
I can hold the boost I set until redline...

If I tune it to 18psi, It holds 18psi to redline

I have an auto and NO FMIC.....
that's all well and good, but plenty of people have said they can hold 18 psi to redline .... the question is, if you set it to 19 psi can you hold that to redline? how about 20? 21? 22? etc., etc.,

what is the highest ?
 
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Discussion Starter #4
billvp said:


that's all well and good, but plenty of people have said they can hold 18 psi to redline .... the question is, if you set it to 19 psi can you hold that to redline? how about 20? 21? 22? etc., etc.,

what is the highest ?
Exactly, what's the highest boost one has seen their stock turbos HOLD to redline ?? This is actually a very important question and pertains to all supras modded up to the BPU+ level...I'm surprised we're not seening any more input on this.:confused:
 
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Discussion Starter #6
aznsupra said:
my car holds 1.5 bar to redline, thats 3rd in my auto, never redlined in 4th, a lil too fast for comfort!!!
Wow !!! ...now that's the answer I was looking for...1.5 bar (22PSI) to redline is VERY strong for stock turbos. Toyota really went all-out as far as production-spec turbos go with turbos that can HOLD 22 PSI to redline !!!:eek: :eek:
 
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Discussion Starter #7
I doubt many stock twin can hold that much boost to redline due to stock wastegate. anything over 20 is usually a momentary thing, a boost spike. if you can hold 22psi to redline, congrats, there are always freak turbos out there.
what kind of boost controller are you running anyway?
 

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Maybe my car is a little different here.......but i run no boost controller....just run pulled hose...so wide open wastegate. Now i am talking from a dead stop.....racing the 1/4 mile......so dead stop 1st through end of 4th gear.....most boost i hit during that time on cold nite..is 1.4-1.5 And what i hold to redline in 4th is about 17. I have the greddy peak hold guage...so i know what most i am hitting is throughout the whole run..and once i get in 4th gear.i watch the boost guage....and by redline it bleeds down to about 16-18. Never anymore though. I have never in a 1/4 mile run held over 20 psi to redline.....And my 1/4 mile times speak for themselves. I run 11.48 @ 124.....and average 11.7s at traps at 122 + So all in all run consistant high -mid 11s at this boost level.....so i have a 6 speed so maybe autos hold more boost....but for all those that are holding 20+ to redline.i would think 1/4 mile and traps would be a little higher and more evident...if in all the theory of more boost = more power. All friends 6 speeds all have the same pattern as mine in the 1/4 mile as well. And i am full bpu++++ front mount, tuned afc, run race fuel etc etc. So i think realistically most hold 17-18 at most to redline in 1/4 mile run, at least in a 6 speed. Now on a 4th gear roll on i can easily hit over 2.0 bar..:) but that is a different story....lol Hope i helped answer your question.
Tony
 

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My 2 Supra's and my friends 3 Supra's all drop to about 17psi by redline. You could probably do things to get them to hold boost better, but the turbo's would probably go out soon if boosting 20psi all the way through the rpm range.

Later, Steve
 

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No matter what boost I make midrange, I'm down to ~17 psi by redline in 4th.
 

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Zerosoul said:
I doubt many stock twin can hold that much boost to redline due to stock wastegate. anything over 20 is usually a momentary thing, a boost spike. if you can hold 22psi to redline, congrats, there are always freak turbos out there.
what kind of boost controller are you running anyway?
The stock turbos are blowing hot air at that kind of boost. I've heard 19 lbs w/ front mount is about the most reliable air flow. I've had my boost gauge reading 1.5 bar at the track a lot. I don't believe it was delivering that power consistantly. That was with stock turbos,downpipe,cold air intake, exhaust, FMIC,boost control,VPC, GCC...the rest of the BPU+ garbage.
Zerosoul is right on the money....but being polite. Andi Baritchi was running unbelievably strong on stock twins. I would ask him...
 

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the ? did NOT mention the stock wastegate, just max boost on stock turbos (usually defeating wastegate altogether).

Zerosoul said:
I doubt many stock twin can hold that much boost to redline due to stock wastegate. anything over 20 is usually a momentary thing, a boost spike. if you can hold 22psi to redline, congrats, there are always freak turbos out there.
what kind of boost controller are you running anyway?
 

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I can hold about 19.5 psi to redline in 4th on pump gas/65 deg weather; I don't know what I could hold in 5th to redline, but the peak is 22 psi or slightly more. So I bet in cool weather with race gas healthy stock twins could hold over 21 psi in 5th or 6th at least. :cool:
 
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Discussion Starter #15
twinturboman said:
the ? did NOT mention the stock wastegate, just max boost on stock turbos (usually defeating wastegate altogether).

wastegate controls how much turbo boost. so eventhough your turbo wants to boost 25psi, your wastegate has to "allow" it.
 

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Zerosoul said:
I doubt many stock twin can hold that much boost to redline due to stock wastegate. anything over 20 is usually a momentary thing, a boost spike. if you can hold 22psi to redline, congrats, there are always freak turbos out there.
what kind of boost controller are you running anyway?
bleeder t's....i kno it holds 1.5...ive watched it many times...and thats after installing my fmic...it used to boost 1.4 in 3rd kinda strange that i actually got a pressure increase with my fmic. i have since put in a trust manual boost controller since i wanna save my turbos. i have it completely closed off. so its around 14-16 #'s

one more thing....at tx2k2, while running the 550, i got it up to o/d and it was at 1.6 and holding steady, but i stopped b4 redline so i couldnt tell ya if my turbos would hold that to redline.
 

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Put a spring on the waste gate and see what you get.

I think the waste gate still opens due to internal pressure, in other words the waste gate's spring is too weak to hold more then what you see now. I have played with external spring on the waste gate and seen mine hold 20psi and spike to 24psi. If you had a BC to control it you might have a better boost control.
set it too something like 18 or 19 and hold it to redline if yours does not already do that now.

IMO Note: On my car at least, spikes over 20psi in the summer would cause the car to ping. That seem to keep the timing down for the rest of the run. So not only too much boost cause you to loose power but a spike could hurt too.
 
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