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compression vs boost

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Old Jan 7, 2012 | 04:19 PM
  #1  
sn95_331_GT_ yellow's Avatar
sn95_331_GT_ yellow
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Default compression vs boost

ive been doing a little bit of research on the matter and am just wondering what you guys think about running boost on a PI swap motor...

now, before everyone says its impossible remember this:

Corvettes run boost all the time and those engines are in the 10.5:1 range. they also at the SMALLEST have a 3.890" bore, we have a 3.552". the smaller the bore the less prone it is to detonation...

case in point, my friends 10:1 Integra ran for 2 years on 20lbs, no problems... with a stock LS longblock...

im only planning on running ~10lbs or so and yes, ill be getting forged rods and pistons as well as bigger injectors and one of the new 340lph pumps...

just been toying around with this idea, higher CR = a lot less lag so maybe this is something i can do, maybe not?

reason i ask is said Integra now has a built motor that is right around 550whp and i cant let him beat me...

plus i just love how turbo V8's sound :
Old Jan 7, 2012 | 04:53 PM
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I'm pretty sure lizzyfan ran his car like that. Don't get crazy with timing or boost and you should be fine
Old Jan 7, 2012 | 05:19 PM
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sn95, mach 1's are 10 to 1 comppression and they run boost. i plan on running 10 to 1when i build a short block so i dont have to spin my blower as hard and hit the same rwhp.
Old Jan 7, 2012 | 05:25 PM
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As posted, just don't go crazy with it. A safe tune is where it's at. The other thing to think about it 'boost' is only a measure of restriction. if you have a good flowing set of heads and proper cams you'll see lower boost but higher hp/tq than a stock car with the same pulley size.
Old Jan 7, 2012 | 05:41 PM
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^+1 to lilroush. I wouldnt get carried away with a particular "psi number". The better flowing setup you have the less boost you'll see, but make more power. As previously stated, just dont get TOO greedy with boost and get a safe tune
Old Jan 7, 2012 | 05:47 PM
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Jazzer The Cat
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My new motor will be 100% forged, have 11:1 and can safely run a couple lb's. It is clearly on the upper edge compression one wants to have, but my plan is to stay N/A. I only want the "option" to reach a few more horsies and can do so, if I choose.

Jazzer
Old Jan 7, 2012 | 06:30 PM
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sn95_331_GT_ yellow's Avatar
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Awesome that's what I guys, thanks a lot for the input, on3performance and 3.55's here I come!!!!!
Old Jan 7, 2012 | 11:21 PM
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Yeah can be done with a good tune like everyone has said also can look into meth or e85 and make it even safer
Old Jan 7, 2012 | 11:38 PM
  #9  
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sn95_331_GT_ yellow
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Yeah i'm gonna look into e85, when I was living in mass before I got divorced we had it EVERYWHERE, I about around here in CT, but there is a station right in town that sells cam2 lol. Go figure...
Old Jan 8, 2012 | 07:11 AM
  #10  
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When you forge the internals, get dished pistons. It will lower your compression ratio to allow for higher boost. I know -23cc dished pistons, will make your compression ratios about 8.9:1 which is close to the ratios that the 03/04 Cobras run at.



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