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max boost on stock head gasket

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#21 ·
sr20damn said:
unless you guys have seen these things happen yourself dont say anything about it. i have a t25 AND a stock headgasket on blacktop s13 and run 20 psi as my high boost setting, it has even spiked to 21 before and the turbo is still running good
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well that's not helping you much because it's out of it's efficiency range at that point. you can do it, but there's no point in it except to say "i'm running 20psi"
 
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#22 ·
sr20damn said:
unless you guys have seen these things happen yourself dont say anything about it. i have a t25 AND a stock headgasket on blacktop s13 and run 20 psi as my high boost setting, it has even spiked to 21 before and the turbo is still running good
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Good for you

I know of many people who have boosted their T25 @ 20psi too but as Uno pointed out...

uno said:
well that's not helping you much because it's out of it's efficiency range at that point. you can do it, but there's no point in it except to say "i'm running 20psi"
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So pat yourself on the back... you run 20psi :thumbsup
 
#23 ·
you guys are so quick to try and make someone feel stupid........im not running 20 psi just to say it, i can feel a power difference as opposed to 14 psi. and i also plan on upgrading turbos so thats why im boosting it so much. if the turbo goes then it goes. but for jedi to say that they crap out at 14 is ridiculous and it sounds like he got that from the internet and has no personal experience
 
#24 ·
sr20damn said:
you guys are so quick to try and make someone feel stupid........im not running 20 psi just to say it, i can feel a power difference as opposed to 14 psi. and i also plan on upgrading turbos so thats why im boosting it so much. if the turbo goes then it goes. but for jedi to say that they crap out at 14 is ridiculous and it sounds like he got that from the internet and has no personal experience
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I would say you are lucky. At that level it's just a matter of time. Think of how much you'll have to spend if the motor blows instead of the turbo.

My turbo blew (and luckily not my motor) so I'm upgrading it along with the clutch, head gasket and changing to ARP head studs. I'm also getting the motor dyno and street tuned.

Why spend a grip now? Because I don't want to spend even more because of a blown motor down the road.
 
#25 ·
ok you probably do notice some difference. i'll give you that. but probably no more than running it at 16 or 17. If you can, dyno 17 and 21 psi and i bet they make the same power. Not trying to make you feel stupid. Just trying to let you know in case you weren't informed. Sorry if i came across the wrong way. My friend has a stock turbo srt-4 and it's efficiency stops at 18psi. He makes the same power within 1 hp at 22psi and at 18psi. but his a/f ratios suck at 22psi so once again, no harm meant. Get the new turbo on there.
 
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#26 ·
sr20damn said:
you guys are so quick to try and make someone feel stupid........im not running 20 psi just to say it, i can feel a power difference as opposed to 14 psi
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Its the way you are saying/wording it then perhaps...

But I highly doubt your butt dyno is accature enough to measure the actually power difference from 14 - 20 psi. I say you dyno @ 20psi, then drop to 17psi then 14psi and tell us what the "actual difference is" not to mention a/f ratio


General Rule of Thumb is 1psi = 10hp (on setup it may vary)

stock SR is around 170whp @ 7psi.
7psi = approx 70hp... 170 + 70 = 240whp say.

Well you are running 13psi more "instead of my example of 7psi" so appox 130hp + the 170 = 300whp ? You'll be lucky (Depending on your setup) to hit 230whp @ 14psi and the turbo wont be "efficient" past about the 230/240whp which could be made @ 14psi depending on setup

Hense my answer... "it craps out @ 14psi"
 
#27 ·
I've been running 15-17 PSI on stock head gasket for about 7 months now with no problems. On a Garrett 60-1/T3 Turbo. At ~370whp. But, I am planning on switching to a cometic with ARP studs when I get the money. I would be safe and just install a new head gasket.
 
Discussion starter · #28 ·
okay what everyne is saying is that you shouldn't go past 15 psi on stock head gasket on t25 but i have a gt28r and around 300hp to wheels so could i push 20 on stock or juatbuy a cometic
 
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#29 ·
S14Silvia said:
I would say you are lucky. At that level it's just a matter of time. Think of how much you'll have to spend if the motor blows instead of the turbo.

My turbo blew (and luckily not my motor) so I'm upgrading it along with the clutch, head gasket and changing to ARP head studs. I'm also getting the motor dyno and street tuned.

Why spend a grip now? Because I don't want to spend even more because of a blown motor down the road.
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an sr is not gonna blow from a t25 at 20 psi........these are not b16's. but when i upgrade turbo i will also do pistons headgasket and headstuds
 
#30 ·
sr20damn said:
an sr is not gonna blow from a t25 at 20 psi........these are not b16's. but when i upgrade turbo i will also do pistons headgasket and headstuds
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My turbo was a t28. At 20psi on a stock t25/t28 SOMETHING will blow. Either the turbo will blow, the motor will blow or you will blow your mechanic for his services rendered after you get the bill
 
#31 ·
sr20damn said:
you guys are so quick to try and make someone feel stupid........im not running 20 psi just to say it, i can feel a power difference as opposed to 14 psi. and i also plan on upgrading turbos so thats why im boosting it so much. if the turbo goes then it goes. but for jedi to say that they crap out at 14 is ridiculous and it sounds like he got that from the internet and has no personal experience
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You can try to run that much boost if you like, just make sure you have enough fuel and a nice big intercooler to combat all the heat soak that comes from a turbo working that hard.
 
#33 ·
ok, i do have to mention though that I personally would never try anything close to 20psi without proper tuning and at least a metal head gasket and maybe forged pistons.
20psi usually requires some supporting modifications to run reliably and the stock t25g isnt al all good at that boost. Anything abouve 15psi is just pushing hot air around. It will fall back down to 10psi by redline anyway :(
 
#35 ·
I just got my sr dyno tuned today gt28r at 17psi 275hp at the wheels
so ill see how long my stock head gasket lasts. lol Also is there any write up on how to change the headgasket on the sr. After reading this post makes me wanna change it right away. thanks
 
#37 ·
ive been running on 18psi with 2871R .64 for the past 2 months. I have no knock and a steady 11.5 AFR. As long as it doesnt run lean or knocking occurs, I couldnt see the stocker going out. MA Motorsports runs a stock heagasket on there KA-T drift car that sees 25psi from a T3/T4.
 
#38 ·
There is no magical measurement of boost that stock headgaskets fail at. They fail due to too much detonation or something like that. I would think that they fail at a certain hp level rather than psi level. 14psi on your a t25 is less than the 270hp at 14psi on my gt2871r... just like 18psi on a gt2871r is diffrenent than 18psi on a gt35r.

You need to relate hp to headgasket failure.

Also I think someone needs to search. This subject has been beaten to death on any forum.
 
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