boost vs. compression ratio?

[goose]

Anybody know how much boost can be used with a given compression ratio and still use 92 octane safely? Like a chart of CR vs. Boost for a given octane. Or possibly know where such a chart is located online...

[dewme5]

well. that all depends on timing. that does make a differance. but.. i am running 12 pounds on a 9.0:1 compression ratio. so.... i would say 12 pounds is still in the safe range.

[goose]

Where's your timing set?

[TT440]

The compression vs boost will differ with each engine. What's good for one doesn't always work in another.
I know that 8 psi and 8.7 compression isn't a problem on my 440 with 34 degrees total and 92 octane.

[dewme5]

thats basically what i was getting at.. there is no hard and fast rule for what will work. im running 34 degrees total, but backing it down to 24 when i am at 12 pounds. rather safe than sorry. still in the tuning process, so i hope to bring that closer to 30 degrees. but i would rather be safe than sorry. one head gasket was enough for me

[blownhemi]

better a head gasket than a piston

With my set-up I could only get 6-7psi boost/30 degree's total before detonation and that's with 95octane! I have heard though that our ratings are different to yours.

[dewme5]

well. i am running the new magnum motor.. so they have the better burn charactistics. supposed to be able to run almost a full point more compression on the same gas as the old small block heads. so that is helping i am sure.. Now, the aluminum heads are out, and that should help even more.! wow... push it to 20psi!! what would 650hp rear wheel be like.... on a daily driver. not a street car... but a real daily driver!!!! oh yeah... i feel like wetting my pants!

[TT440]

Now you're starting to feel it! I should be close to that power level at 8 psi. I plan on fueling as high as 15 psi. That should bump 800+ hp out of the Belvedere.
At that point, I'll probably go with a SpeedPro setup.