Race Fuel ?????

[RICKYRJ1]

I have a freind that buys Sunoco race gas for his 462 BB. He keeps buggin me to buy some for my Z, is it worth it once in a while to mix some 100 octane in with the 93? Thanks

[secondchance]

Originally Posted by RICKYRJ1

I have a freind that buys Sunoco race gas for his 462 BB. He keeps buggin me to buy some for my Z, is it worth it once in a while to mix some 100 octane in with the 93? Thanks

My understanding on the suject is that the maximum timimg is programed in ECM and unless you reprogram the timing to take advantage of higher octane (advance), extra octane might refrain timing retard when knock is detected with 93 (100 would be more resistant to knock) but would not yield significant hp.

Just my thought.

[tomtom72]

My question would be "does mixing 100 octane with 93 octane = 96.5 octane?"

Then the next question would be, " does your LT5 need 96.5 octane fuel?" I know your motor has been modified.

JMHO, what is the benefit of using racing gas in a street car that was for sure designed to run of 91 or 93 octane fuel? Heck, according to the owner's manual we can use 87....we just will be missing about 1/3 of our advertised HP.

[PhillipsLT5]

We can only buy 91 octane out here in AZ
Hope this helps
Left side is 92 octane
Top is 100 octane

Gals.
Gallons 1 2 3 4 5 6 7 8 9 10 11
1 96.0 97.3 98.0 98.4 98.7 98.9 99.0 99.1 99.2 99.3 99.3
2 94.7 96.0 96.8 97.3 97.7 98.0 98.2 98.4 98.5 98.7 98.8
3 94.0 95.2 96.0 96.6 97.0 97.3 97.6 97.8 98.0 98.2 98.3
4 93.6 94.7 95.4 96.0 96.4 96.8 97.1 97.3 97.5 97.7 97.9
5 93.3 94.3 95.0 95.6 96.0 96.4 96.7 96.9 97.1 97.3 97.5
6 93.1 94.0 94.7 95.2 95.6 96.0 96.3 96.6 96.8 97.0 97.2
7 93.0 93.8 94.4 94.9 95.3 95.7 96.0 96.3 96.5 96.7 96.9
8 92.9 93.6 94.2 94.7 95.1 95.4 95.7 96.0 96.2 96.4 96.6
9 92.8 93.5 94.0 94.5 94.9 95.2 95.5 95.8 96.0 96.2 96.4
10 92.7 93.3 93.8 94.3 94.7 95.0 95.3 95.6 95.8 96.0 96.2
11 92.7 93.2 93.7 94.1 94.5 94.8 95.1 95.4 95.6 95.8 96.0

[flyin ryan]

Originally Posted by RICKYRJ1

I have a freind that buys Sunoco race gas for his 462 BB. He keeps buggin me to buy some for my Z, is it worth it once in a while to mix some 100 octane in with the 93? Thanks

No.

[GrayZ]

We were sitting in the parkin lot at the Uplaza at a gathering a few years ago....Gordon K. said the same thing, LT5/s don't like the added octane.

[todesengel]

You also have to be very careful when buying race fuel that it is unleaded. You can clog your cats (if you still have them) and foul your 02 sensors. Sunoco is junk in the race fuel world, at least with boosted cars. I have drums of c-16 when I need it, but boosted v. n/a is like comparing apples to oranges.

If you are not pulling timing due to knock, I see no benefits from added octane. Meth/water injection maybe to cool intake charge temp, but not octane.

[RICKYRJ1]

Thanks to all! You guys just saved me a bunch of money