Another cheep solution to having to run 99 octane at the track is the water/meth system. At a 50/50 mix the methanol injected is 118 octane and will raise your 91 octane much higher during boost only. So you can run 91 for daily driving and let the meth system increase your octane during boost only. It's the best of both worlds because a 99 octane on 9.5:1 with no boost will loose power. I run 93 octane day driving with water/meth during boost to 15+ psi with no issues for 25,000 miles on a 10:1 stock M44. You want the least amount of octane the motor will run safe on and if octane is too high you loose power since it is a much slower burn and flame travel which is needed only when adding boost or advancing timing so you don't get detonation. Snow systems is the best in my opinion for less then $400. It is completely tunable for your motor and I run maybe 5 gallons of methanol per year at $2.36 per gallon...Much cheeper then filling up with 99 octane. If you track the car you will want a oil cooler and cooling system mods to keep everyting in the motor cool during a beating at the track |