0Fasterproms

C7 Corvette E85 FlexFuel Conversion Kit

In the last few years E85 has gained a lot of popularity due to its higher octane and heat dissipation characteristics. We have often heard E85 called the "poor man's race gas." E85 is 85% Ethanol. We have seen it test out between 70-90% from region to region, gas station to gas station. Due to the varying alcohol content in production, the air fuel ratio will vary. If the vehicle were tuned at a given mixture (70% for example) and then later filled up with 90% ethanol, the vehicle would require a separate and completely different tune because of the leaner mixture.

The solution is the FlexFuel Sensor, along with adjusting certain parameters within the tune. What we have set out to do is make the Corvette a FlexFuel vehicle. For example, with the FlexFuel sensor inline, we can set up the tune to adjust air fuel and spark proportionately to the alcohol content in the fuel 0-100%. You can run the car on 91 octane or E85 and the car will automatically adjust within moments of filling up. The installation is about 1-1.5 hours. It is not permanent and can be easily reversed.



I took my Corvette to the dyno on 93 octane and brought 10 gallons of E85 with me. On Run #7: 93 octane and headers, we gained 11rwhp / 17rwtq. On Run #11: Our first dyno run with E85, we easily gained 13rwhp / 12rwtq without touching the timing curve, and only adjusting the fuel for the same target air fuel ratio. These gains here were solely from the cooler air charge entering the combustion chamber.

When I was racing the car earlier in the year, I gained 2mph (Same weather as previous weeks, 1600-1700 DA) in the 1/4 mile from the extra spark advance that the car was able to take before spark knock with E85. Whether it was a good thing or not, I had been so busy I wasn't able to make it to the dyno and I was street tuning the car on the way to the track. The main idea here is that the knock thresholds were much higher with the higher alcohol content fuel. The C7 has a very good fuel system from the factory that should be able to support a substantial amount of power. The car is currently producing 534rwhp / 498rwtq.



In a vehicle such as the CTS-V/ZL1/ZR1 equipped with a supercharger, it generates a lot of heat and the engine is longing for more spark advance due to octane limitations. We regularly see 40-65+ rwhp gains from converting to E85 on a CTS-V/ZL1/ZR1. Even lower concentrations of alcohol (30-50% in the tank) blended with 93 octane will yield considerable gains. We often have customers that will run 93 Octane during the week and when they want to play on the weekend, they fill up with E85 for that extra horsepower boost. Each vehicle and motor has it's own knock thresholds, the variables are Intake Air Temperature, Oil Consumption, Compression Ratio, Boost, Octane, etc. E85 has less BTU's than Gasoline. Typically the fuel consumption will increase between 20-30% on E85.

We are currently offering the E85 FlexFuel Conversion Kits for CTS-V, ZL1, ZR1, C7, and we are in the process of developing kits for G8, SS, GTO and many other platforms.

The C7 pricing is as follows:
$450 for the FlexFuel conversion kit
$200 for the supporting programming

11B250

no love for this? not even a single reply...

6Speeder

I like it. Probably do this to my C7Z eventually.

11B250

Curious how you tune the car so that it knows the value of ethanol in fuel and can change the tune based on it. Is the computer even programmable to do this?

Unreal

Yes. Computer has a table for stoich ratrio for % of ethanol, and maps for ethanol, and it takes the sensor input, from 0-100% and uses those maps and tables to adjust for any ratio from 0 to 100% ethanol.

Kracka

GM should have done from the factory! I'd like to see more on how the install is done and how exactly the tuning works.

LT1_E85_Corvette

OMG this is awesome!!!! thank so much for the details. One question, how much for just the tune? and does the tune adjust for weather changes and altitude??

thanks, i'm a very serious buyer

Kracka

If this were somehow compatible or easily added to my current tune, I'd jump all over it since there is an E85 pump not far from my house (plus I work for an ethanol producer).

11B250

then why on earth didn't GM incorporate this into the car? didnt want to lower mpg figures or something?

LT1_E85_Corvette

They are trying to protect the C6Z, that's my thought anyway

Unreal

C6Z can do the same thing.... Any gen 4/gen 5 motor can flex fuel.

They do it on the trucks and other cars, which is why it works on the vette since GM shares ECUs for a lot of cars. Why they didn't do it on the vette, I don't know. None of the major manufacturers have done it on their sports cars.

And the idea that they are doing anything to "protect" and older car that is out of production is beyond silly. If they wanted to protect that, fix the damn heads.

11B250

I think he's referring to more so the fact that they want C6Z to be more powerful compared to a C7. They still want C6Z to rule over C7s since they're "special" corvettes.

C7's goal was to outshine the GS. not the Z06

Unreal

No.

GM doesn't care about last years models or making them look good.

11B250

well, why the hell isn't flexfuel part of this car then if we all need is a damn sensor to gain more power and have same drivability? lol

I don't think GM woulda made C7 base have more power than a C6 Z06. but then you look at the tq curve and they talk about how it's identical to the Z06s, so maybe they really don't care... lol

LT1_E85_Corvette

I don't think it's necessarily just the C7 vs C6Z which i stated earlier. But that they wanted to protect the LS7 (which is still in production). Who would want a 7lt if a 6.2lt on e85 makes nearly the same power if not a little better? I mean the power would be identical from a smaller displacement motor. I feel confident this is it

11B250

yes, that's true. I agree. I knew what you meant. it can be taken for motors vs cars.

I remember when C6 came out and the big thing was "can C6 beat C5Z" consensus was no at the time. C5Z still took a C6 by inches.

thegame

Do they have E85 in Jersey?? I never see it.

T/A KID

The programming is easy, I've posted the necessary pics of what needs to be changed.

Ls3 in this thread posted pics. I have around $100 in my flex fuel kit. All it takes is 3 wires and my buddy Dave (Dsteck) on here is sending out the e92 ecu pin so I can finish up my install.

The LT1 would make 500 hp with e85, I believe that is what its not capable from the factory

11B250

What's. Wrong with 500 HP? That woulda been one helluva advertisement for gm. If anything keep it quiet but make it flex fuel capable and let owners figure it out themselves lol. And to make sure were talking 500 at crank correct? Lol

RonC7

Is the C7 fuel system compatible with E85? More than 10 or 15% ethanol is more corrosive and requires upgraded elastomers and other wetted components.