91 octane highest compression ratio?
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What is the highest compression ratio that you can safely run on 91 octane gas because that is the highest i can get my hands on out here in colorado?
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I run 11.2 with 28 degrees of timing with cali 91. I would stick around 11.5 or lower, and go with a thinner head gasket to reduce quench. You will need to tune it to cancel any knock. Detonation killed my last 11.8-1 346ci.
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Yeah I would say 11.5:1 is the most you could get away with on 91 with max timing, that's what my heads/cam setup was and it ran fine on CA 91 octane. A lower lsa cam and colder plugs will help too will help bleed off some compression too. Good luck.
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Colorado is like 1000 miles above sea level right
Your mass flow efficiency will be less than Cali so I would guess that you could get away with more compression than an equivalent car in CA. Isnt this one of the reasons you have 91 in CO?
I say go with a supercharger! That would be huge where you live.
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Your mass flow efficiency will be less than Cali so I would guess that you could get away with more compression than an equivalent car in CA. Isnt this one of the reasons you have 91 in CO?
I say go with a supercharger! That would be huge where you live.
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Originally Posted by SSpeedracer
Colorado is like 1000 miles above sea level right
![EEK !!](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_eek2.gif)
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Eric D.
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