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rpoz27
07-29-2008, 04:39 PM
Anybody know where to get a fuel sample tested?
Wirtz
07-29-2008, 07:53 PM
I got a lighter...
BryanL
07-29-2008, 10:06 PM
What do you need it tested for? Pretty sure the NHRA tests fuel at their races so there might be some info on their website. Otherwise I would try a racing gas distributor/company?

This brings up a question I have been curious about so I will do the usual hijack.

What affects to the different seasonal gas supplies have on us? As well as the may contain up to 10% ethanol? I am curious what affects it has on power, detonation, fuel consumption.
Al Fernandez
07-29-2008, 10:30 PM
During summer months it is hotter, so fuel is formulated differently to lower the amount of vapors generated at ambient temperatures. This is good for the environment as well as for the car, since as you're evaporating off light ends the fuel loses specific energy and raising the flash point. This is why your weed wacker runs like a toilet when you fill it with gas thats been sitting in the garage for three months. It should have a negligible effect on a modern FI engine since in our configurations in CMC. A really high strung AIX motor might be a different story though. I have no idea the impact to carburetors...my grandpa or Adam might know though.
AI#97
07-31-2008, 04:01 PM
Same tune with "summer" gas and summer heat results in a 15hp and 12tq loss on my motor...

Hopefully it will cool down in Ohio soon!
Al Fernandez
08-01-2008, 09:43 AM
Thats pretty surprising to hear Matt, but it does make sense. Are you adjusting initial timing to get that?
AI#97
08-01-2008, 11:02 AM
Thats pretty surprising to hear Matt, but it does make sense. Are you adjusting initial timing to get that?

No changes at all but we CAN add more timing but have to run more race gas.

Dyno's will correct for air density, humidity and temp...however, they cannot account for the computer pulling up to 10 degrees timing based on intake air temp! The newer ford cars with higher compression ratios that are advertised to run on 87 octane are pretty bad about this and the 4V cobra Computers are TERRIBLE about losing power when the water temp goes above 220-230 and intake air temp over 95! Another thing to watch for is an updated dyno in July/August being used to validate AI power for a race in late october. If I were to add 3 degrees timing in August to counteract the summer power loss, and raced the car in October, I could be 20hp over my numbers VERY easily with dense air.