Hey guys, I am running an AEM EMS tuned by yours truly and I will be doing quite a few track days this season.

My Question:

I would like to run race fuel for additional protection against knock in the desert heat. I won't have access to a dyno at the track when I do this. Is there a percentage I can advance timing such that the car will run smoothly. I am not terribly concerned about peak power but I don't want the car running like crap because I put 110 octane in the tank.

I'm assuming race fuel is tuned to the same AFR's as pump gas. Is this correct?

Thanks!

Jorge

 

Yes, race fuel runs the same AF. At least non oxygenated race fuels. To be safe, I wouldnt touch the timing at all if youre not able to see what is going on on a dyno run while messing with it. Putting race fuel in will suppress detonation much better than pump piss if there could possibly be a problem with the pump piss. Just put it in as an extra safety measure and you will be fine. Nothing needs to be changed as far as timing or AF.

 

Simple question, simple answer. Thank you very much!

 

you will probably lose hp by just adding much higher octane fuel without optimizing both the fuel and ignition curves.

 

When i switched to toluene/6 from 93 oct. i picked up 30+whp next pull.(from 300 on 93)

It depends on which fuel you are using.

edit- Use your internal logging and log your knock sensor/AFR with race gas. Make changes to the AFR as needed.

 

Agreed.

If you aren't going to tune the car with the race gas in there, then I wouldn't do it at all.

 

No problem man.

 

I dont think he is concerned if he was to lose a few ponies by running race fuel without getting it tuned for it. I think he was only wanting to know if it would be ok and still run well but have safer protection against knock. It will still run the same as if it was on pump piss, just may be down a few ponies but highly unlikely and I'm willing to bet he wouldnt even notice if it was down a bit.

BTW, you dont need to go with anything like c12 or c16 for what youre wanting to do. Something mild like Sunoco unleaded 100 will work perfect or Sunoco leaded 110 (although the lead can wreak havoc on o2 sensors over time) but I dont think you will need anything that high of octane for what youre wanting to do and thats just to have that extra bit of safety over detonation. Also, Sunoco unleaded 100 isnt much more expensive than regular unleaded 93. I think its around $4.50 a gallon, maybe even cheaper.

Hope this also helps.

 

You know what's funny? I happen to have a 5 gallon drum of toluene in the garage. Incredible stuff.

You obviously advanced timing to gain the 30 HP, right? It doesn't just come from the fuel.

 

Thanks again for the advice. I'll run 100 octane at the track. If I get a chance, I'll go out and make a couple pulls on the stuff to optimize my timing but finding a dyno for rent around my area is a PITA.

Thanks everyone for their input. Good stuff!