T&T Racing

I run 100 octane in my Porsche 944, no knock control, CRG of about 11. The 100 octane is achieved by mixing 91 ethanol free with 110/112 leaded race fuel in a 50/50 ratio. Ethanol free is less than $3/gal and 110 race fuel is $9/gal or the mixture is $ 6/gal

sctanton52

I ran 100LL in a 'modified' MGB street car for a few years back in the 80's. Yea I know it was on the illegal side. I had easy access to to the fuel. I had removed the Cat, shaved the heads to get about 11.5. Ran like a top for some 20,000 miles. It finally met its maker in a a ditch in central Alberta, on a rainy day, I walked away, well I limped away. I still run 100LL in all my small engines. Two modern aircraft tugs, with B&S Engines, a 2-Cycle chain saw, a Snowblower, a Power Broom, etc etc etc. I love that you can leave the gas in them for a long-long time and never have to worry about things getting all gummed up.

d15b7

i've never tried the octane boosters, but I'd be worried that the octane wouldn't be high enough and consistent enough to be sure that you'd avoid engine killing detonation in a race engine. might be fine for a street car driven application though

stownsen914

Last time I looked into octane boosters, you had to use a lot of the product to get a meaningful bump in octane. To get 100 octane, you'd have to use many bottles of booster. But that was admittedly a long while ago - maybe they've improved since then.

txhokie4life

What about running E85? You'd have to change the injectors to increase the flow -- but that would give you an effective octane boost.

I'm considering doing the same for my RSR race engine.

Mike

d15b7

hey Mike! see my above long detailed post concerning E85 and my experiences with it.

yes when I converted over to E85 I had to change the fuel pump (upsize it) and change all the injectors (upsized them by 60%) and spent a full day on the dyno retuning to get the max benefit from the E85

Mister C

You could, in theory, use toluene or xylene to boost the octane of gasoline. Available at paint stores. Cost vs track-bought fuel? Ymmv

stownsen914

Good point. I'd consider doing that if I had any information on amounts, octane increase, etc.

d15b7

maybe it's just me, but i think i'd be more concerned about creating engine damage on my expensive car by using a fuel created by a home brew of chemicals that I'd purchased at a paint store, vs using carefully controlled/produced aviation fuel?