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Time for change
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Discussion Starter #1
Just as the title describes.

I'm looking to see what NA-T owners on the TT headgasket on pump gas are achieving.
 

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Time for change
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6,868 Posts
Discussion Starter #3
Hehehe.. I know that, I'm looking for examples so I can start interpolating my own data to give me a base line.
 

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173 Posts
Don't have the graph with me. But with the ignition breaking up so bad it shut off the dyno at 5000rpms I made 424whp/515tq on a DaveH kit [email protected] PSI. (should be about 450whp now that the ignition is fixed)

TT headgasket and 525cc injectors
Lexus AFM (trying to switch to a VPC if I can find one)
SAFC-II tuned about 11.7-and dropping to 10.8 at redline.

Graph can be found in my gallery page on the link below in my sig.
 

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Time for change
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Discussion Starter #5
Oh, wow, thats actually pretty good!
What timing were you running that you got 16.5 PSI with no knock? 93 octane right?
 

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EFI Certified Tuner
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1,877 Posts
Don't have the graph with me. But with the ignition breaking up so bad it shut off the dyno at 5000rpms I made 424whp/515tq on a DaveH kit [email protected] PSI. (should be about 450whp now that the ignition is fixed)

TT headgasket and 525cc injectors
Lexus AFM (trying to switch to a VPC if I can find one)
SAFC-II tuned about 11.7-and dropping to 10.8 at redline.

Graph can be found in my gallery page on the link below in my sig.
matt, how did you fix the ignition break-up?
 

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Oh, wow, thats actually pretty good!
What timing were you running that you got 16.5 PSI with no knock? 93 octane right?
Stock base timing, 93 octane. I'm right at the edge of the timing and compression for my car. I've heard of people getting 14-18PSI depending on the turbo and the car itself on TT headgasket.

matt, how did you fix the ignition break-up?
HKS Twin Power and NGK 3330 copper plugs gapped @ 28. I think my iridiums were the problem, as soon as I put the HKS on I basically lost 2 cylinders spark. Changed out the plugs and everything has been running good since. The old plugs were NGK Iridiums at heat Range 6 and I think the colder 3330s are helping a lot as well.

Now I just need to figure out a rich spot when I initially floor the peddle, and my tuning is done. I think that is related to my fuel regulator but still investigating that. Stock FPR @110,000 miles may be worn and allowing a brief spike in the pressure on initial pressing.
 

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Turbo Lexus SC 300 '94, 427rwhp @ 15 psi, 60-1, vpc w/440 chip, 440 inj., gcc.,
npr intercooler, greddy exhaust, hks midpipe, stock auto tranny, tial wastegate, greddy blow of valve, TT head gasket.

We only stopped because we didn't want to blow the tranny on the dyno.
 

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Time for change
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6,868 Posts
Discussion Starter #9
Those are some pretty good numbers. I was hoping to be able to get around 450 WHP with my setup on pump.

SP kit- P72 .81 Ar, 5-speed, 3 inch no cat exhaust, Apexi exhaust.
4 Row Intercooler, All the fueling I'll ever need.
Boostwerx Intake manifold with 90MM TB
Cam gears set to stock GTE positions.
 

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Time for change
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6,868 Posts
Discussion Starter #11
It kinda counts. It seems though as you go higher in gasket size that it may not be helping very much.

Sure you probably could have made 425 WHP, but there are people on the TT head gasket making more power with less boost.

I think increasing the squish volume has a drastic effect on power output, while it may allow you to run more boost it would seem one would loose the ability to produce power beyond what would have been made at that compression level with the appropriate squish volume.

In other words, severe diminishing effect to using thicker head gaskets.
 
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