max psi with stock turbo

[1dollardog]

What is the max psi someone has gotten from a stock hot air turbo? Been tuning mine somewhat and have installed diy alky. I am getting no knock at 18 psi but that is all the psi I can seem to squeeze out of the turbo with the adjustable wastegate accuator. Is this about right? Seems to spool up kind of slow to me but tops out at 18 psi on a 20 psi boost guage. I also have a TT chip but its not burned for alky.

 

[tb3]

may want to have tt burn you the correct chip. with a non-alky tt chip i was running 17 psi during hotter months on just 93 octane with 0 knock. my car seems to like more fuel and timing in first/second gear. during winter when it gets below 45 degrees, i've ran up to 19 psi

 

[Boost231]

I've run 20psi on 93 octane with no knock on a cold night and good tune

 

[Jerryl]

What is the max psi someone has gotten from a stock hot air turbo? Been tuning mine somewhat and have installed diy alky. I am getting no knock at 18 psi but that is all the psi I can seem to squeeze out of the turbo with the adjustable wastegate accuator. Is this about right? Seems to spool up kind of slow to me but tops out at 18 psi on a 20 psi boost guage. I also have a TT chip but its not burned for alky.

I think you are asking;
How much boost can I get out of the stock turbo?
Depends on the set-up and tune.

If the set-up is rich, it will limit the boost.
Best way is a WB and EGT.

If you "run out of turbo" at 18 PSI with a good tune on a stock set-up, you are doing good! I suspect the chip is off. Get an alky chip from TT.

 

[1dollardog]

Thanks for the info.

 

[1984grandnat]

I "accidentally" made it to 26 psi with the stock turbo and alky once, but I can't recommend it...it seems that anything past 20 psi or so doesn't result in an increase in power output, it only makes the "knock gods" unhappy. :frown:

 

[Jerryl]

.....it seems that anything past 20 psi or so doesn't result in an increase in power output, it only makes the "knock gods" unhappy. :frown:

Very true . . .
It is always a balancing act between the variables especially on a HA.

If a TA33 is done in the real world at 23 PSI, I would think the stock is done waaaaay below that.
But, I have never seen a compressor map for a stock HA turbo to compare, and don't have personal experience at that boost level with the stock turbo.