[chiphead]

Honestly I would just run pump premium in the main fuel tank. If it doesn't ping on the street it's not going to at the track. A experiment would be to make 2-3 passes on half a tank of only pump premium and then 2-3 with 5 gallons of VP110 added on the same day. If it doesn't go more than a tenth or two faster, you don't need it. 1 gallon of race gas per 5 gallons of pump premium isn't moving the octane much anyway. Blending your own witches brew fuel makes tuning harder.

For the N2O fuel system, it depends on several engine factors. Running 110VP LL would give a wider tuning window. You would have to pull less timing. It would also color the plugs better for tuning. Just don't tune it for VP110 and then accidentally run 93 pump gas. That could be bad. Find a basic race fuel easily available to you and stick with it. Don't switch from VP110 to something else chasing the dragon. That'll make tuning a mess. Take detailed notes every pass.

[pokey1]

Originally Posted by chiphead

Honestly I would just run pump premium in the main fuel tank. If it doesn't ping on the street it's not going to at the track. A experiment would be to make 2-3 passes on half a tank of only pump premium and then 2-3 with 5 gallons of VP110 added on the same day. If it doesn't go more than a tenth or two faster, you don't need it. 1 gallon of race gas per 5 gallons of pump premium isn't moving the octane much anyway. Blending your own witches brew fuel makes tuning harder.

For the N2O fuel system, it depends on several engine factors. Running 110VP LL would give a wider tuning window. You would have to pull less timing. It would also color the plugs better for tuning. Just don't tune it for VP110 and then accidentally run 93 pump gas. That could be bad. Find a basic race fuel easily available to you and stick with it. Don't switch from VP110 to something else chasing the dragon. That'll make tuning a mess. Take detailed notes every pass.

Thanks for the recommendations Chiphead.. I have not noticed any pinging but when running race gas it does seem to run cooler on the hot days. You are right that I do need to be consistent on what I am running and will get more consistent times. Thank you for the reply.