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Discussion Starter · #1 ·
From which manufakturer i can buy pistons with this CR?

I see only 8,4, 8,5, 9:1
but i want to lower it more.

Greetings
Frank
 

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512RWHP... 503RWTQ... 7M
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Pardon the question, but, why? How much boost are you planning on running?
 

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Not your average auto mk3
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CP can probably make any compression you want (they made us a 9.5 for the 7m) btu my question is why 7:1? Even if you plan to run alot of boost, its still way too low in my opinion.
 

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Not so boring anymore
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more boost on pump gas maybe? im not sure.. but off boost power will be compromised..
 

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Discussion Starter · #5 ·
Yes because of Boost... Want to run 35PSI. And on this way i have not so many probs with the egt and i can run more ignition advance. Want that the engine is more effectiveness at high boosts.
That the engine needs more fuel without boost is ok it is only a funsupra.

Thanks for tips, and sorry that i am not so easy to understand. :D
 

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7:1 is also going to murder gas economy, and your 35 psi will make the power of ~25 psi on a 9:1 motor with slower spool and awful response.
 

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run a 8.5-9:1.. just use good fuel at high boost.. and meth if you want more on pump
 

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Mitsubishi Starions are 7:1 stock. So its not unheard of. Just my 2 cents.

Dennis
 

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survyor2 said:
Mitsubishi Starions are 7:1 stock. So its not unheard of. Just my 2 cents.

Dennis
They also had one of the worst OEM fuel system ever on a turbo car.
 

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Wreckless said:
They also had one of the worst OEM fuel system ever on a turbo car.
^TRUTH.

I had one...lol.
 

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Wreckless said:
They also had one of the worst OEM fuel system ever on a turbo car.
True...I STILL have one.
 

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me me me me me me!!!
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i know i'm highjacking the thread but how many are running 9:1 pistons. what is your experience with them, better driveability off boost, better mileage, better throttle response.

have you been able to run the same amount or almost the same amount of psi on pump as stock comp. ratio with more power and no detonation. assuming you have a good tune.
 

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Slow66 said:
CP can probably make any compression you want (they made us a 9.5 for the 7m) btu my question is why 7:1? Even if you plan to run alot of boost, its still way too low in my opinion.
no need to say anymore...Rewriting the book I see :nutkickhi
 

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survyor2 said:
True...I STILL have one.

yuppers we had guy at my old work that was starion junky i used to make fun of him alot
 

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475RWHP 449TQ and climing
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tunaman said:
i know i'm highjacking the thread but how many are running 9:1 pistons. what is your experience with them, better driveability off boost, better mileage, better throttle response.

have you been able to run the same amount or almost the same amount of psi on pump as stock comp. ratio with more power and no detonation. assuming you have a good tune.

Get a standalone and tune it, and you will be fine :bigthumb:
 

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Discussion Starter · #16 ·
I have a stand alone i drive AEM.

I think not that it is so bad to run 7:1

the F1 turbo engines run at 6,5:1 with 45PSI and use methanol and so on + waterinjektion.

I want to drive with good normal fuel because of i can get it everywhere. And use water injection.

Because of the worser fuel it can not be so wrong to run 7:1 at 35 PSI or why drive the F1 turbos 6,5:1?

And when i think i have too low HP because of the low cp i will run more boost. its easyer to run more boost as to change again the pistons.

i use the power each time i drive the supra and too up to max RPM in 5. gear because of no tempolimmits.
 

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VollNormal said:
I have a stand alone i drive AEM.

I think not that it is so bad to run 7:1

the F1 turbo engines run at 6,5:1 with 45PSI and use methanol and so on + waterinjektion.

I want to drive with good normal fuel because of i can get it everywhere. And use water injection.

Because of the worser fuel it can not be so wrong to run 7:1 at 35 PSI or why drive the F1 turbos 6,5:1?

And when i think i have too low HP because of the low cp i will run more boost. its easyer to run more boost as to change again the pistons.

i use the power each time i drive the supra and too up to max RPM in 5. gear because of no tempolimmits.
EIP Tuning in Maryland built a street driving conquest that used the stock 7:1 compression with Ross pistons, nos, big turbo, head work, etc. Ran a 10.6 in the 1/4. There are videos of it somewere on the net. The compression might have been even lower due to the copper headgasket.

Dennis
 
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