Im going to head up the local drag strip and i was thinking of buy like a gallon of like 114 octane fuel, i was wondering how high of an octane fuel can a FD motor take??

 

Stay away from the leaded stuff. Aside from that, knock yourself out.

 

cant you run leaded pretty safely if you have a heated o2 sensor?

 

leaded will kill your cat as well as your O2.

 

What martini said. Do a search on "leaded fuel" if you want to know more.

 

I common misconception is that higher octane fuel increases performance on it's own. The only reason for higher octane is to prevent preignition (a.k.a. knocking or pinging) when using aggressive ignition timing and very high boost. Use toluene if you're that concerned.

-Jon

 

I've run Elf 114 unleaded, and it doesn't work well with my FD. I've found anywhere between 100 to 110 unleaded works well, but 114 seems to stifle the motor...

I run the high octane for road racing events to prevent pre-ignition, not for performance...although, there must be some performance benefit...it certainly "feels" faster with unleaded 104 (Sunoco) or 110 (CAM 2?)...

 

Thats a great misconception, using race gas, or very high octane fuel with no added boost or advance timing gives you less hp, the fuel burns slower, and is less reactive, this is why it prevents pinging, it combusts less easily. You use race gas to run more boost or timing or both, otherwise, it gives no or less performance than regular gas. The lower the octane, the more volitile it is, if you could run 15psi on 89 octane, youd make more power than at 116 octane.
Rob

 

Hmmm....then I'm saving my motor from pre-ignition!

 

so how high should i go with unleaded fuel??