Supercharging at 11:1 Compression
05-29-2006, 01:25 PM
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Supercharging at 11:1 Compression I feel like this might be a stupid question but would it be okay to supercharge a motor at that high of compression? (11:1) I know that typically superchargers like a lower compression but I'm thinking ahead for when I'm bored with my heads/cam to add a little more. 
Just wanted to get some guidence to see if I'm thinking crazy. Thanks
Just wanted to get some guidence to see if I'm thinking crazy. Thanks 
05-29-2006, 03:20 PM
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I'm in your shoes right now. Right now, my LT4 has a 11:1 compression ratio with 52cc heads. I also have my vortech s trim waiting to go in, I so want to just drop it in right now, but I keep reminding myself to do it the right way and save up for dished forged blower pistons or get my lt4 heads ported/polished. Whatever you decide to do, do it the safe way!
05-29-2006, 05:43 PM
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yea dont do it yet, its not worth the time or effort to just trash your engine, a friend of mine did that after I told him not to and it lasted like a couple weeks then one day he hit it hard on the freeway and BOOM there went his Z28 up in smoke
05-29-2006, 06:01 PM
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Don't do it. Number one it's just not worth it. At that compression you would be able to run like 3 psi of intercooled boost at the most.... that's worth about 50hp maybe..... you'd barely feel it..... If you ran more it'd detonate like a **** regardless of octane unless you know of a gas pump station that carries 120 octane unleaded..... maybe then you could run 5-6 psi.....
Nitrous at this point is your only choice. Other than running a headgasket that is thicker than a three ring binder.....
At 11:1 you could run a healthy dose of bottle with ZERO problems assuming you've got some nice forged pistons... even if you don't have forged pistons you should be able to run a safe 100-150 shot with your fueling sorted out...
Nitrous at this point is your only choice. Other than running a headgasket that is thicker than a three ring binder.....
At 11:1 you could run a healthy dose of bottle with ZERO problems assuming you've got some nice forged pistons... even if you don't have forged pistons you should be able to run a safe 100-150 shot with your fueling sorted out...
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05-29-2006, 06:53 PM
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I know of one shop that likes high compression with boost and limits timing to make it work well Mease Performance Engineering in souther NJ. The SYSTEM is all important, if you try to run conventional timing with 11:1 and any signifigant boost bad things will happen but that doesn't mean it is impossible to run boost and decent compression together. That guy is also fond of alky injection.
05-29-2006, 07:59 PM
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I was just responding normally based on his sig.... doesn't look like he wants to be running alky injection on what seems to be a daily driver.... yes it can be done but for so much less cash invested he can either build a low compression motor or use nitrous.... for normal guys without tuning knowledge he's not gonna want a supercharger with that much compression...
05-30-2006, 12:31 AM
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Just so you guys know, I did build this motor with forged pistons in mind of possiably wanting an extra power adder down the road. I've been questioning how good of an idea running a 150 shot would be on a motor which I have just invested THOUSANDS of dollars into. I know some of you will tell me that there is no gaurentee that it will hold up and something can go wrong, however I'm looking to get an idea on more of a technical stance of "how well will it work"?
05-30-2006, 01:25 PM
#12
Since you are thinking about something down the road it would probably be easier to sell your Heads/Cam setup when you are ready to supercharge and go with an aftermarket casting with a larger combustion chamber to drop the compression down so you can take full advantage of the power adder.
05-30-2006, 01:31 PM
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Run a thicker headgasket and if you blow the engine, then redo the whole engine just how you want it.... you were considering doing that anyway. Who knows, maybe the headgasket will drop your compression low enough to where you won't blow anything.
05-30-2006, 01:35 PM
#14
Running a thicker gasket is far from the best solution, and unless you run a much thicker gasket there won't be enough drop in compression to make a difference. Either way not a good idea.
05-31-2006, 09:25 PM
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if you've got forged pistons already and 11:1 compression then you have a motor already built for a 150 shot if not more....
You talked about the motor possibly blowing up well a supercharger can do just as much if not more damage.... hell driving it up to the redline can blow your motor apart if something goes wrong.... a properly setup nitrous kit on a motor with forged pistons should give you at least a few years of fun.... provided you're not going thru bottles like a 2 month old baby... Nitrous is like candy. you eat too much and you're bound to get cavities..... and a cavity in your motor is not what you want..... Eat that candy in selective amounts and you'll be fine.... And do your research. cannot say that enough. a safe nitrous system is a combination of parts designed not only around maximizing power but also minimizing possible screwups like fuel pressure drop, too hot on plugs, over-revving your motor, etc..... get the bells and whistles for a good kit. bottle warmer, fuel pressure safety switch, window switch, etc..... it goes like this....
RESEARCH, PLAN, RESEARCH, PLAN, PURCHASE, RESEARCH, PLAN, INSTALL, USE.......
in that order....
You talked about the motor possibly blowing up well a supercharger can do just as much if not more damage.... hell driving it up to the redline can blow your motor apart if something goes wrong.... a properly setup nitrous kit on a motor with forged pistons should give you at least a few years of fun.... provided you're not going thru bottles like a 2 month old baby...
Nitrous is like candy. you eat too much and you're bound to get cavities..... and a cavity in your motor is not what you want..... Eat that candy in selective amounts and you'll be fine.... And do your research. cannot say that enough. a safe nitrous system is a combination of parts designed not only around maximizing power but also minimizing possible screwups like fuel pressure drop, too hot on plugs, over-revving your motor, etc..... get the bells and whistles for a good kit. bottle warmer, fuel pressure safety switch, window switch, etc..... it goes like this....RESEARCH, PLAN, RESEARCH, PLAN, PURCHASE, RESEARCH, PLAN, INSTALL, USE.......
in that order....
05-31-2006, 09:52 PM
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Originally Posted by 96capricemgr
I know of one shop that likes high compression with boost and limits timing to make it work well Mease Performance Engineering in souther NJ. The SYSTEM is all important, if you try to run conventional timing with 11:1 and any signifigant boost bad things will happen but that doesn't mean it is impossible to run boost and decent compression together. That guy is also fond of alky injection.