Reach a little far back on this one, but hey, I'm whoring up the forums tonight and it comes with the territory.
I run race gas at least once a week at the track. I prefer to only run actual automotive race gas. The formulations for aviation fuel aren't necessarily what a turbo auotmobile engine needs... That being said, my local track sells Sunoco race fuels, my usual choice is the 118 octane version at 11 bucks a gallon. There are lower octane options, starting with unleaded 100 octane at ~7.25/gallon. Above 104, it's all leaded.
If you can provide enough fuel for your airflow, and have the means to tune properly, race gas like this will allow you to just about max out your setup. The knock resistance is unreal. To use my EVO as a current example, I run 25 psi on pump gas with about 8 degrees of timing advance. With race gas I run 32 psi with ~15-16 degrees advance. I haven't had a clean run on race gas this year due to some small issues, but I expect it to trap 122-124 on race gas on the turbo, and it traps 116 on pump gas. That's a nice solid increase. On the dyno it was a 50 whp difference, having some high boost issues. I expect it to be a 80+ whp difference when it's maxed out. To use a typical DSM example, you'll run about 15-16 degrees on pump, and ~21 degrees on race gas, plus much more boost. I have always been able to pick up approximately 5 mph and 5 tenths at the least, that's about 50 whp at our weight, on my various setups.
To give an idea of how hard you can push it on race gas with proper setup/tuning, I was running the EVO with the wastegate actuator line removed (WG doesn't open at all) for maximum boost, plus a 75 shot, with 20 degrees of timing.
I head up to the track with no more fuel than I can pump out into an empty 5 gallon jug. I keep a seperate 5 gallon jug for the race fuel, which I dump in after pumping out the pump gas. After I'm done racing I pump the race fuel back out into it's jug and dump in the pump gas. I typically get 4 gallons back out, so each trip up I only need to buy one gallon to top off the jug. Easier on the wallet and the O2 sensor.
Cats will die with about 1-2 months of wekly race gas use as described above. The O2 sensor will last quite long if you give a new sensor at least about 1000 miles of pump gas use first. The pump gas presumably coats the sensor protecting it somewhat from the lead contamination. I usually get a full year out of each sensor.
Hopefully this is the info people were looking for.