OliverM5

I'm in Cali w/ crap 91 octane gas. Currently pushing about 640 rwhp through a stock block LS7 with cam, headers, A&A blower @ 5-6 PSI. Can I safely make more power with meth? If so, what can I expect?

BADZ

I wouldn't go much more unless you forge the rods/pistons and do arp hardware...

Oh, also replace those junk 2 pc valves!!!!!

Unreal

Si-trim will make out around 71-720rwhp is you really push it.

Kadorja

I would immediately upgrade the valves, springs and pushrods. They're the first thing to go if you get a little happy and peg the rev limiter.

68/70Vette

At a car show a couple of weeks ago, a Z06 owner, was claiming 740 rear wheel hp with an A&A centri supercharger. Said it was installed by A&A Corvettes.

68/70Vette

You can buy high octane gas if you want to pay the premium. I bought 10 gallons of 110 octane fuel at $10 a gallon maybe a couple of years ago. I used most of in my 68. I don't know how much it costs now. I bought it from a local speed shop. There's a major dealer in Long Beach. The high octane fuels are available in leaded and unleaded. I buy unleaded so I can pour a glug or so into the 08. I keep meaning to go and get some more. I want to run my 08/A&A Supercharger at the drag strip and before I do, I'll put in some high octane leaded just to help out. I had my car dyne tuned at A&A and Andy said that one of the few fuel additives that he used that really worked was "Torco." He wanted to make sure that I didn't have any fuel in my tank higher than 91 octane so that my tune would be compatible with pump gas.

IMPORTANT COMMENT ABOUT "RACING FUELS" Do you want to fill up your tank with alcohol free fuel? Pump gas in Ca is 10% alcohol. Alcohol has significant corrosion issues. If you have a car you don't drive often, you don't want alcohol in the fuel. The option is to buy alcohol free racing fuel. To buy an alcohol free fuel, don't buy racing fuels that are "oxygenated." Oxygenated is a code word for alcohol infused gasoline.

In the off chance that you might own a WWII P-51 fighter plane, you should know that you can buy 140 octane leaded aviation gasoline.

Also, in the early 1980's I had a clone L88 engine in my 1969. Milled the piston domes down 0.100 inches to get a 11.5:1 compression ratio. High octane Av Gas was a solution. I went and bought so many Jerry cans of AvGas at the Torrance Airport, that the guy at the AvGas station gave me a break. I'd pull my 69 Corvette around on the backside of a building and he'd fill me up with AvGas directly. I'm sure no way anyone would do this today.

Unreal

What blower do you have? 740 out of t-trim is perfectly reasonable. 740rwhp out of a si-trim, not so much.