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How much HP gain from raising compression?

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Old Mar 21, 2006 | 03:07 PM
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Default How much HP gain from raising compression?

Say I have a Forged H/C motor running stock compression.

How much would I gain if I were to pull the heads, mill them down and bump compression to 11.5-12:1.

Next question, Say I've got a 200 shot of N20. Would that be too much for that high of a compression?

Car already has ARP Head bolts and Cometic Gaskets.
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Old Mar 21, 2006 | 03:24 PM
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Originally Posted by jaypee1217
Say I have a Forged H/C motor running stock compression.

How much would I gain if I were to pull the heads, mill them down and bump compression to 11.5-12:1.

Next question, Say I've got a 200 shot of N20. Would that be too much for that high of a compression?

Car already has ARP Head bolts and Cometic Gaskets.

Approximately 2% for half a point… You really need to find out what your DCR is and what it will be to find out if it will run on 93 octane...

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Old Mar 21, 2006 | 03:31 PM
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Dynamic is the better of the 2. Good job SideStep.
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Old Mar 21, 2006 | 03:33 PM
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Dcr???
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Old Mar 21, 2006 | 03:34 PM
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Dynamic Compression Ratio
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Old Mar 21, 2006 | 03:37 PM
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hmm...found a calculater but dont know all the #'s to put in... any help is appreciated guys. just trying to get some insight.
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Old Mar 21, 2006 | 03:39 PM
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what is the link to the calc?
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Old Mar 21, 2006 | 03:40 PM
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http://www.rbracing-rsr.com/comprAdvHD.htm
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Old Mar 21, 2006 | 03:42 PM
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i've got Crower 6.125 Length Rods, Diamond Piston w/ a 2cc valve relief, stock 346 crank.

5.3L heads that are already milled .15. I cant remember what the intake runner size is:dunno:
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Old Mar 21, 2006 | 03:44 PM
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Who put together your heads?
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Old Mar 21, 2006 | 03:45 PM
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https://ls1tech.com/forums/advanced-engineering-tech/467109-how-figure-optimum-dcr.html
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Old Mar 21, 2006 | 03:46 PM
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Originally Posted by orangeapeel
Who put together your heads?
They're TEA Heads. Stage 1.5 5.3L, 2.02 int/1.55exh
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Old Mar 21, 2006 | 03:50 PM
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well the valve relief will take a tad bit away from what you had to start with.
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Old Mar 21, 2006 | 03:51 PM
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Nitrous enjoys the higher compression.
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Old Mar 21, 2006 | 03:51 PM
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Originally Posted by orangeapeel
well the valve relief will take a tad bit away from what you had to start with.
yeah, the shop that built the short block for me said they ran it through a calculator, and i'm at 10.85:1 right now.
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Old Mar 21, 2006 | 03:56 PM
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That is what I am at as well in my Z28 with forged parts and diamonds with -2cc's.
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Old Mar 21, 2006 | 03:57 PM
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Whatever your cam is and how much you are wanting to shave off the heads will need to be determined with PTVC. And the reliefs will help you ouot in that arena as well.
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Old Mar 21, 2006 | 04:01 PM
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i've got the MS3 in the car right now.
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Old Mar 21, 2006 | 04:05 PM
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Ok, so you have a big cam that will enjoy having the hose on it. Im not sure what would be a safe bet for a 200 shot on those heads wihtout physically checking. you probably can take a tad more material off, but it might be more trouble than it is worth. Just get a tornado and stuff it in the bellow and call it a day.
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Old Mar 21, 2006 | 04:08 PM
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Originally Posted by orangeapeel
Ok, so you have a big cam that will enjoy having the hose on it. Im not sure what would be a safe bet for a 200 shot on those heads wihtout physically checking. you probably can take a tad more material off, but it might be more trouble than it is worth. Just get a tornado and stuff it in the bellow and call it a day.
oh snap, i'm all over that tornado.
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