Effective Compression Question
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From: West Palm Beach Florida
Effective Compression Question What up guys? I was wonder if anyone knew what the best effective compression ratio you can run on 93 octane... i.e. I want to run 9.5:1 with 10psi of boost which gives me an effective of 16.6:1... Is this too much, too little? Thanks
Mike
Mike
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From: WWW.SPEEDINC.COM
Originally Posted by MadMike93TA
What up guys? I was wonder if anyone knew what the best effective compression ratio you can run on 93 octane... i.e. I want to run 9.5:1 with 10psi of boost which gives me an effective of 16.6:1... Is this too much, too little? Thanks
Mike
Mike
There are ALOT of variables that determine how much boost/power you can make on pump gas.
You need to analyze -everything- when deciding how much power your going to try and make with a certain fuel.
Thread Starter
Teching In
Joined: Aug 2004
Posts: 46
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From: West Palm Beach Florida
Originally Posted by INTMD8
Effective compression ratio calulators are worthless IMHO.
There are ALOT of variables that determine how much boost/power you can make on pump gas.
You need to analyze -everything- when deciding how much power your going to try and make with a certain fuel.
There are ALOT of variables that determine how much boost/power you can make on pump gas.
You need to analyze -everything- when deciding how much power your going to try and make with a certain fuel.
Ok... Then I have several questions if you all don't mind...
1.Less restrictive or more restrictive exhaust system with good back pressure?
2.How many degrees of Retard per pound of boost?
3.What Air/Fuel Ratio on 93oct
4.If I wanted to add a 50 shot of NOS on top of the boost, does it have to be a wet shot or dry shot on an LT4 with a MAP sensor? no MAF
Thanks
Mike
FormerVendor
Joined: Dec 2001
Posts: 2,444
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From: WWW.SPEEDINC.COM
Originally Posted by MadMike93TA
Ok... Then I have several questions if you all don't mind...
1.Less restrictive or more restrictive exhaust system with good back pressure?
2.How many degrees of Retard per pound of boost?
3.What Air/Fuel Ratio on 93oct
4.If I wanted to add a 50 shot of NOS on top of the boost, does it have to be a wet shot or dry shot on an LT4 with a MAP sensor? no MAF
Thanks
Mike
1.Less restrictive or more restrictive exhaust system with good back pressure?
2.How many degrees of Retard per pound of boost?
3.What Air/Fuel Ratio on 93oct
4.If I wanted to add a 50 shot of NOS on top of the boost, does it have to be a wet shot or dry shot on an LT4 with a MAP sensor? no MAF
Thanks
Mike
1- less exhaust restriction is always better
2- boost vs timing is not a linear relationship. If you pull "X" amount of timing per psi boost, your timing curve will be less than ideal. You want the least amount of timing at peak torque, which can be accomplished through tuning the ecu.
3- Depends
4- You can use either. Are you running SD on a stock PCM, or aftermarket?
A few (of many) things to consider when building a combination, after your goals have been established-
compression ratio
cubic inches, and how they are attained
target HP level vs target boost level (helps when choosing a compressor)
combustion chamber shape (cyl head and piston)
camshaft
quench distance
cooling system
exhaust backpressure
compressor/intercooler efficiency (intake air temp)
engine load (vehicle weight, gearing, transmission, intended use and duration of WOT)
Only "combinations", that are put together and designed as a "combination" as a whole, rather than looking at each part of the car as a separate entity will truly be efficient.
-Everything- has to be considered, attention to detail is what separates average from outstanding.
Rather than asking how much effective compression you can run on 93 octane, I would suggest starting with a horsepower goal, and design the combination to meet your goal, also considering fuel type, driveability, etc.
Originally Posted by MadMike93TA
What up guys? I was wonder if anyone knew what the best effective compression ratio you can run on 93 octane... i.e. I want to run 9.5:1 with 10psi of boost which gives me an effective of 16.6:1... Is this too much, too little? Thanks
Mike
Mike
