Compression Ratio Survey

[FBSideoiler427]

What is the highest compression ratio you SII afficianados have employed successfully in your motors and the highest boost achieved reliably?

Ill post this in the general tech forum also.

 

[Alky V6]

11.27 to one. 22 psi boost reliably.

28, it blowed up. That equates to a dynamic CR of aroud 32 to one. Yipes!

 

[FBSideoiler427]

11.27 to one. 22 psi boost reliably.....

Holy gargantuan cylinder pressure, Batman!

Talk to me, bandit!

Whats your combo? I'm all ears.

 

[John Wilde]

9 to 10 to 1 in not un heard of, especially with big single turbos.

 

[Big88]

Cr

I have 9.95 cr and just ran 28.8 psi. it ran like a scalded cat!

 

[turbodragster]

45

149runs 9.2 45lbs. of boost no problem 150 runs 9.2 45lbs. of boost bent rods

 

[Reggie West]

11.27 to one. 22 psi boost reliably.

28, it blowed up. That equates to a dynamic CR of aroud 32 to one. Yipes!

Thats on alcohol (dont remember which one ).

 

[Alky V6]

Thats on alcohol (dont remember which one ).

Methanol. Don't let anyone tell you methanol is only 110 octane.

 

[Reggie West]

Methanol.

Just dont want him to try that on C-16 race gas.

Ouch.

 

[turbodragster]

it was on gas b ut it was real good gas and i got an awsome intercooler air temp 45degrees

 

[Alky V6]

it was on gas b ut it was real good gas and i got an awsome intercooler air temp 45degrees

I've heard of racing gas with octane numbers in the high 120s. Is it true? Or is it a fairy tale? The stuff developed for the turbo import crowd? You would have to have something 124 octane or higher to do what your doing.

 

[turbodragster]

well you right there is a special gas it is an import fuel but its rated at 120++++++ and its $23 per gallon so allot of people do not use it but it does work

 

[turbodragster]

we are going to find out what the limit is its all about how far your willing to push it. we have been 6.51 @ 207 and we are going to try to get more we just went from 70mm p-trims to 70mm GTS tubines and from an ar68 to ar 81 so we will have to see we finally got the car tuned to spool with gts wheels we got 25lbs on the two step and have 40lbs on the waste gates should do somthing

 

[Alky V6]

Sounds like fun. Let us know how it goes.

 

[Otto J]

we are going to find out what the limit is its all about how far your willing to push it. we have been 6.51 @ 207 and we are going to try to get more we just went from 70mm p-trims to 70mm GTS tubines and from an ar68 to ar 81 so we will have to see we finally got the car tuned to spool with gts wheels we got 25lbs on the two step and have 40lbs on the waste gates should do somthing

Any chance youll be draggin it to bowling Green?
This i would like to see

 

[turbodragster]

i don't think im going to be able to make it to bowlinggreen but we have to see i got allot of testing to do so i will have to see