race gas revisited, why and when? Options

[Trekkor]

Bought a five gallon jug of leaded 110 octane "VP" brand racing fuel. (IMG:http://www.914world.com/bbs2/html/emoticons/ohmy.gif)

My motor seems to have higher than stock compression. Lowest is 160 PSI.

My speed shop guy says the valves will like the lead. (IMG:http://www.914world.com/bbs2/html/emoticons/chowtime.gif)

Maybe I just like throwing money out my open windows at speed... (IMG:http://www.914world.com/bbs2/html/emoticons/huh.gif)

KT

[Jake Raby]

An engine tuned for pump gas will normally make LESS power with Race gas!

This is because of race fuel having more viscosity and a slower burn to prevent detonation with higher CR.

When running race gas the engine can stand much more timing if its a medium CR based powerplant... Here is a "for instance" for ya.

My Hybrid 2316 was dynoed on pump gas (93) and race gas (110). With the pump gas the engine wanted a 140 main jet and 29 degrees full advance to crank out a 13.5:1 AFR and good fuel curve. When the race gas was added the engine liked 36 degrees of timing and a 155 main jet to attain the same AFR and similar fuel curve! This is a 10:1 street/track dual purpose engine.

So many times I see guys go to the track, add race gas and their cars run like shit..... Race gas isn't magical.
BTW- "AVGAS" is wayyy different than Race gas.. Aircraft engines operate below 3800 RPM, and accelerate slowly. They lack cylinder pressure that our engines must have for snappy acceleration. AVGAS also has lubricants in its composition that can harm normal fuel system parts that are not set up for it...