TE/TC Hearing detonation in front of motor

Key points:
-100LL is not 100 octane as we rate it for pump gas (R+M/2). It is actually ~96 octane by that measure.
-Quality and consistency is better than pump
-Shelf life is better than pump.
-Cheaper because you are not paying Road Taxes. Legally it's like running red dye... no no on the street.
-Lower Specific gravity than pump (density) means you actually run leaner with the same jetting.
-Important one here! Lower flame speed than race gas. 100LL is designed for 3500RPM operation. If you run consistently higher than that you will be spitting unburnt fuel out the pipe. Most pre-run or play cars don't spend too much time over 3500RPM

The burn rate has a lot to do with fuel mixture and compression. All high octane race fuel has a slower burn rate, if you're "spitting unburnt fuel out the exhaust" then you need to tune the engine not blame the fuel. This is the opinion of the VP guy and once again no scientific proof. Can you produce proof that AV100LL is specifically designed for engines operating at 3500 rpm and should not be used in any other application? VP has specific literature on each one of their fuel products but I question the VP salesman who is making claims against AV gas since he is motivated to convince you to spend $4 more per gallon. Like I said in an earlier post, lots of opinions yet no proof of the claims.

I agree VP110 is better than AV100LL but the only engines that I have tuned that ran noticeably better on VP110 were maxed out on compression requiring higher octane and VP110 allowed me to get a little extra out of the engine by changing the spark and fuel curve. This makes perfect sense because 110 is obviously higher octane than 100 no matter how you rate it.

Here is a page of opinions that I mostly agree with.
http://www.dragracingpinoy.com/arti...-info/78-tech-tips-aviation-gas-vs-racing-gas

To sum it up;

AV100LL is good to about 11:1 Compression ratio and is a good fuel filling the gap between pump gas and race fuel.

No matter what fuel you use tuning is required

First this was not from the VP guy and was from a science nerd I know that study it for a thesis....

If you can read.....

Av Gas is 96 octane so about the same as pump premium.....

the consistency IS better......

Spitting raw fuel if not rejetted which means no "opps" I forgot to get Avgas so I will just run pump.....

Yes i have to agree on pump gas is not good, who knows probably worse than av gas for racing. I mix 20% race with pump till i can find a marina that sells non ethanol 93 or 95 oct.
Yes i read av gas for low rpm but my riding style sounds like a cessna 172 at 3500ft anyway, i hardly rev high

Well, I ran the VP110 at a scramble today and had no sign of the noise. I'm putting paid to this one. Thanks for the advice, all. Carry on.