Raising compression

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Sep 4, 2023 | 02:30 PM

Garbageman 134

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Raising compression

I have random thoughts about random things all the time and this popped into my head recently. The factory compression ratio is 10.5:1. Is it possible to have the heads milled down in order to bump up compression for a little more horsepower?

Would be nice to install the ProCharger kit but then you have to run 93 octane all the time

Sep 4, 2023 | 02:37 PM

Ltngdrvr

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Quote:

Originally Posted by Garbageman 134

Well, you could, but milling the heads creates all sorts of other things that then have to be compensated for, so to do that right would cost a fortune, not be worth the small gain. Plus raising the compression ratio would cause the same fuel requirement as the supercharger.
You could get as much added power from a dyno tune as from the increased compression.

Sep 4, 2023 | 06:33 PM

OBS460

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You want to lower compression if you don't want to run premium.

Sep 4, 2023 | 06:36 PM

Garbageman 134

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At what point does one need to switch to 89 or 93?

Sep 4, 2023 | 06:50 PM

OverheadCram

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Quote:

Originally Posted by Garbageman 134

At what point does one need to switch to 89 or 93?

When there is predetonation present. With that said its not as cut and dry as that when engineering a combustion chamber along with the rest of the engine. There is no set compression ratio that is the benchmark switchover point for a higher octane fuel.