Dyno'ed an FRS with 104 octane in the tank!
 

Was doing some testing a few weeks back on a Dynojet. Tank was damn near empty by the time we were all done so we dumped a gallon of Sunoco GT Plus into the tank (rated @ 104 octane RM2).

Guess how much power we made?

ZERO!!!

Maybe a tuner can chime in but it seems like this ECU uses a torque limiter and is locked down pretty good from the factory. Not easy to make power on this car without a reflash. Any truth to my suspicions?

PS - I'm in Cali and all we get is 91 oct (RM2).

I would say: yes, that is true

Octane don't make power. It makes the flash point higher. The only reason why you loose power with lower octane is that the ECU pulls timing due to knock. If you get no knock with a given fuel, increasing octane from there will not yield you more power.

why does this surprise you??

If anything, i'd expect it to lose power without adding timing while running 104 octane.

I know with my mustang running 93 produces more horsepower thanks to CVVT. Dynos proved it. Too bad the 86 doesn't produce more power with a higher octane.

Did you, out of curiosity, pull the battery ground? Only asking because I did this on the dyno and made 11whp more though I was low on the pulls done before this.

Yea im starting to think our ecu's are very sensitive and whenever something is done to the car that effects timing, air fuel etc the ecu has to be reset...

:popcorn:

I've talked to John about this. He mentioned that race gas didn't do squat as well.

It's surprising given the gains on E85.

What the fuck. That is mind blowing

yea didnt do anything :/....maybe a 3hp-4hp gain..even if it made 11whp its about $50+ for 5 gallons e-85 is the best alternative right now i think.

You won't make gains with E85 and no tune. Straight 104 is just too much of a jump. If there was enough timing advance available to run 104, there would be motors dropping left and right on pump gas.

You could mix that 1gal of 104 with 5-6gal of 91, and see a bump on the OEM tune. I've seen it on other Subarus, BMWs, Porches, etc running 93, so I'm sure it would help with California gas.

I understand this, but he was tuning 104....