i cant remember... if i go to the track and theyre selling 110 or whatever, is it okay to just throw that in? or should it be tuned for it? i cant imagine it would hurt anything...

it would most likely be mixed about 50/50 with 93 from the pump..


also, if its okay to use, would you expect to see any power gains simply from the fuel??

 

Its adding a margin of safety, and without a tune needed. Its just an increase in octane, so if/when your IAT increases along with overall demands on the engine, it could help save it, especially if your tune isn't great for track duty demands. Its a detonation suppressant.

 

Higher octane gas is more resistant to knock. This allows the engine to run at a higher compression ratio, more spark advance, and a better power mixture. The car must be tuned to take advantage of the higher octane. Using higher octane than your car requires will not provide more power. In fact, higher octane gas actually has slightly lower energy per gallon than lower octane gas. Using higher octane will not harm your engine - just your pocketbook. However, if you have a catalytic converter and the higher octane gas has lead in it then the lead will damage the catalytic converter.

 

Some race fuel have different stoich ratings than regular pump gas, this could make your engine run too lean which can cause damage.

 

In my experience, the car runs richer on track gas. Its non oxygenated, unlike normal pump. And as the poster said after me, a high OCT fuel has a lower combustion energy. That's going to make it run safer.

 

The conclusion should be, find out what the actual fuel is and see what the spec is before just assuming things.
I'm sure 9 times out of 10 it's perfectly fine but seems a bit unnecessary to risk it.

 

Ok, its tuned by john from jk, and runs great. My wastegates dump out the hood and when iats are over 110 or so, a 2nd gear pull will generate enough fuel smoke to leave a trail. Its like 10.5 or so, real rich. Id like to try some pump 110 from the track, even for an autox day and see if it won't lean out a little while also being safer....?

 

Chances are it will have the opposite effect, run even richer. Safer maybe, but not if your running so rich you start getting pre ignition or fuel washing the cylinders. Sounds like you need a better tune to accommodate your higher IAT conditions regardless. Your ecu ideally should be keeping your afr on target regardless of the IAT and pull timing rather.

 

I’d find out what the exact fuel is. Find it’s stoich. If stoich is in line with what you’re already tuned on or really close to it... then fill up and it’ll help prevent knock/detonation. I like to think of it as getting tuned on 87, then using 93 octane when tracking. Slight stoich difference could be mitigated by fuel trims and if it’s slightly more lean, added octane level will prevent detonation but you could lose power. Etc etc. This is just my opinion.