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I know that when you run a TT set up the likelyhood of engine Knock increases significantly due to the air being pumped into the cylinders under pressure by the turbocharger, and then being further compressed by the piston . From what I've gathered the Knocking happens because as you compress air, the temperature of the air increases and The temperature may increase enough to ignite the fuel before the spark plug fires.

I ran my Blown C5 at 12PSI boost with minimal to no knock , would this be a safe amount of pressure to run my Viper on 91 Oct ( Providing we didn't pull to much timing out )??

Thanks !

:cheers:


Jeff
 

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Jerome said:
Loaded question.

Too many variables to answer this. Need lots of specifics to give a realistic answer. All the rest would be just speculation.
Exactly. I mean we are talking timing, fueling, air temps, air flow (as opposed to boost pressure), etc.
 

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Yellow Fever said:
I know that when you run a TT set up the likelyhood of engine Knock increases significantly due to the air being pumped into the cylinders under pressure by the turbocharger, and then being further compressed by the piston . From what I've gathered the Knocking happens because as you compress air, the temperature of the air increases and The temperature may increase enough to ignite the fuel before the spark plug fires.

I ran my Blown C5 at 12PSI boost with minimal to no knock , would this be a safe amount of pressure to run my Viper on 91 Oct ( Providing we didn't pull to much timing out )??

Thanks !

:cheers:


Jeff
Jeff, knock happens when the air/fuel mixture ignites BEFORE it is supposed to while the piston is on the way up. When this happens, the piston gets a ghetto ass whipping on the way up instead of a hammer on the head for the way down on the powerstroke. This may not be the most scientific way to explain it, but it is the way I understand it.......I think a lot depends on the compression ratio{are you getting the motor rebuilt?} and the type of tuning you will have. I know Heffner will be using the AEM with knock sensors. I am no tuning expert, but I am sure he will figure it out. Just make sure you get a fresh tank of 91 octane in the car before you send it to Heffner.
 

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Paolo Castellano said:
Yellow Fever said:
I know that when you run a TT set up the likelyhood of engine Knock increases significantly due to the air being pumped into the cylinders under pressure by the turbocharger, and then being further compressed by the piston . From what I've gathered the Knocking happens because as you compress air, the temperature of the air increases and The temperature may increase enough to ignite the fuel before the spark plug fires.

I ran my Blown C5 at 12PSI boost with minimal to no knock , would this be a safe amount of pressure to run my Viper on 91 Oct ( Providing we didn't pull to much timing out )??

Thanks !

:cheers:

Thats a real good and simple explaination!! I was never sure if this happend on the up stroke or not. I have read with 8:1 comp and forged internals you can run up to 15 lbs, but its a trial and error type thing.


Jeff
Jeff, knock happens when the air/fuel mixture ignites BEFORE it is supposed to while the piston is on the way up. When this happens, the piston gets a ghetto ass whipping on the way up instead of a hammer on the head for the way down on the powerstroke. This may not be the most scientific way to explain it, but it is the way I understand it.......I think a lot depends on the compression ratio{are you getting the motor rebuilt?} and the type of tuning you will have. I know Heffner will be using the AEM with knock sensors. I am no tuning expert, but I am sure he will figure it out. Just make sure you get a fresh tank of 91 octane in the car before you send it to Heffner.
 

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The answer will be different for every tuner and every combination - and all the different answers will probably be right.

Does that help?

:lolcry:

The limits of the past are not the limits now, but your tuner must be your guide as only in tuning will you know the truth...

and the truth shall set you free

/images/graemlins/biggrin
 

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Im sure you can run 11-13 lbs safely. You may have to pull out a degree or two more than the 93 cars, but your HP loss would only be 50-75rwhp...which is a lot, but not when youre talking 950ish HP.
 
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