No E85 near me - but I have 112 . . .
 

So, there isn't a single E85 station in Louisiana. None that I can find, anyway. But, NOLA Motorsports has both a 106 and a 112 octane pump.

For track days, I'm thinking about putting in one of these. I'm pretty sure it'll need a tune (haven't asked around, but I'm certain it will). They question is:

If I get a tune like this, can I then go back to running regular 93 octane later in the day, or will I need to retune the car somehow (reflash with HP Tuners or some such thing)?

(Let's assume that, both when I put 112 in the car, and then switch back to 93, I'm running the tank almost dry, so I'm not mixing the fuels overly much.)

106 and 112....sounds like leaded. That would be bad.

If the track has unleaded, it's usually 100 or 104. No tune required, it's still gasoline. If you had a map switch in the ECU [for example], then you could have a more aggressive ignition map for the higher octane fuel, assuming the engine isn't already at MBT.

Given that PRAY has found that the stock ignition map is already quite aggressive with 93 octane, a tank of 100 would feel more consistent through the course of the day.

First as said, make sure it "unleaded" only fuel. Some of the higher octane stuff can be leaded aviation fuel.

Also you really don't need a full tank of 100/104. The can wont run any better from it and could actually run worse on it. The higher the octane the slower the fuel burns to combat detonation. We don't get 93 in Oklahoma anymore so I run 6 gallons of 100 octane and then the rest is 91 octane to bring me up to around 94 octane. That is plenty for what a stock car will need.

Race trac in ponchatoula, la has e-85. If your in New Orleans that's the closest place.

You would have to have your car tuned to run e85 plus have the flex fuel kit or the high octane fuel you are talking about and deff needs to be unleaded. Your car will not pick up any hp with the octane you have above. I would just stick with 93.

They're all unleaded fuels. It's Sunoco GT260 Plus.

Yeah, I know I'd need a tune and the flex fuel kit. I'm just wondering if, after you get a tune to run those, do you HAVE to run them all the time? Or, will the car still run fine on 93?

And, good to know about Ponchatoula! I know that Racetrack. Used to work at North Oaks, so I went there all the time. Unfortunately, I now work/live in New Orleans, so wouldn't make it up there a lot. But, I could definitely make the trip prior to a track day and fill up my tank.

Sunoco's highest octane unleaded is 104, just FYI. GT260 Plus is the highest and it's 104.

Just be careful you don't put leaded in the car. Leaded ruins cats and O2 sensors.

Here's a thread where Scott Foremaster (Director of Racing Operations, I think is his title) details the types of fuels.

He doesn't say what the 112 is. But, if I can get e85 an hour away, it's worth it to not pay the $12/gal that even the 104 costs.

https://nolamotor.com/NOLAforum/showthread.php?tid=143

Ah, that makes sense. Agreed on all counts.

The flex fuel kit only senses ethanol content. It can't tell what octane your gasoline has.

OK, but if I get a tune for e85, can I still run 93?

Steer Clear of E85
 

Folks, please be careful with E85. When I worked in GM Powertrain Service Engineering, we were working on the requirements for supporting E85. At that time, the only small block engines we were making E85 capable were truck engines. In order to make E85 capable, we had to have special hardening processes on the valves and valve seats for certain. We may have actually done the camshaft also, but in all honesty I can't recall that for certain.

Without the special hardening, valves and valve seats could become pitted due to the high ethanol content. Gasoline engines are engineered to be capable of managing E10, not E15, not E20 and DEFINITELY NOT E85 without the special hardening.

I will contact some folks on the Small Block Engineering Team and get detail on whether or not they still have concerns about E85 in LT1. I am almost 100% certain that they will say no way / no how.

More on E85
 

Ok, I spoke to the Chief Engineer for Small Block. Some good news / bad news here....

GOOD NEWS:
When LT1 added Direct Injection, the hardening processes were added, so all small block V8s get the hardened valves, guides, and seats, so no risk of ethanol corrosion or pitting

BAD NEWS:
If you do not add the fuel sensor, you run a very high risk of mismatched air fuel calibration, leading to likely pre-detonation. I've noticed that most of you talking about using E85 are aware of the need to add the sensors.

MORE BAD NEWS:
The fuel pump in the LT1 does not have the capacity to manage the flow volume required to fully take advantage of E85. It requires more volume than gasoline or E10. His suggestion is to save the expense of the E85 sensor and just use octane boost. It will probably result in the same level of performance.

Hope that was helpful.

Lots of folks running E85 here with full boltons.