E85 (E50) vs 100 octane race tune?
 

Hey guys, I just had the DSX flex fuel sensor installed and dyno tuned earlier today. I have a Halltech CAI, Borla X-pipe and the 2.3 upper pulley. The car is at 25 degrees of timing at WOT. She's running great on E50, but I have to admit, I'm a little surprised that it put up the exact same dyno numbers as my 100 octane custom tune. It was on the same dyno with the same tuner, but I realize there are other factors at play. I'm going to the drag strip on Saturday and that will tell the tale. Just curious if anyone else has seen similar numbers? Apparently most of the guys seeing 40 rwhp on E50 are comparing it to the stock 93 tune.

Thoughts.

yes of course it's similar to running 100-105 octane. the benefit of E85 vs race gas is price. 2-3 dollars for E85 and 10-12 for race gas....plus not having to swap tunes with flex fuel.

Yeah, I understand. I guess I was just expecting 'some' power gains? Guess we'll see what she does at the track? Thanks Higgs

e85
 

What happened? ET's? MPH?

While E-85 would be expected to increase the octane, the additional cooling benefits take place after any of the GM air temperature sensors. So I'd expect that one would need way more than the average "tuner" to bring the cooling benefits into play

Is there likely to be much damage to the fuel system if you were to use a tank of E85 sporadically? I know our cars are not built for exclusive E85 use.

No damage will incur to the OEM fuel system using blended ethanol content.

I'm tuned with 92 octane. 100 octane is expensive but boy you can tell car really goes animal when I add 5 gallons to the tank.

What about this section from the owner's manual??

Recommended Fuel (LT4 and LT5 6.2L Supercharged
V8 Engines) Prohibited Fuels Caution (Continued) (MMT), which can damage the emissions control system and spark plugs.
. Fuel with a posted octane rating of less than the recommended fuel. Using this fuel will lower fuel economy and performance, and may decrease the life of the emissions catalyst. Caution Do not use fuels with any of the following conditions; doing so may damage the vehicle and void its warranty:
. For vehicles that are not FlexFuel, fuel labeled greater than 15% ethanol by volume, such as mid-level ethanol blends (16–50% ethanol), E85, or FlexFuel.
. Fuel with any amount of methanol, methylal, ferrocene, and aniline. These fuels can corrode metal fuel system parts or damage plastic and rubber parts.
. Fuel containing metals such as methylcyclopentadienyl manganese tricarbonyl
(Continued) Do not use any fuel labeled E85 or FlexFuel. Do not use gasoline with ethanol levels greater than 15% by volume.

Don't get back out to the track until next weekend. The waiting is killing me

That's the liability portion from Chevrolet basically stating that they will void your warranty over every little thing. The reality is that fuel systems have been designed to handle E10/E15 for years now. If you're running a blended mixture you're not going to ruin anything. If you are running full E85, you are more likely to have issues. But it's a moot point to discuss that since the stock setup can't handle full E85 anyways.

Factory untuned car I would NOT add a tank of e85!

You need the flex fuel and a tune. For daily use E85 is overkill. For a run at the track and wanting to squeeze you all you can, yes Go For It!!! I run E30 as I can get it blended at the pump that way but also have 93 as well. The Butt-O-Meter can't tell the difference between the two. I also run meth and a lowside fuel pump as you need extra help when running full E. I am putting down 675/725 with all my mods with full E.