Slow Poke

Anyone think there is a chance of E85 or flex fuel equipment being installed from the factory? I personally don't think they will due to added costs but it would really cool if they did offer that as an option. There could be some extra ponies available and cheaper fuel costs too!

96ss#80

I hope so!!! Can you imagine the tuning options! Even if you never tuned it the higher octane of the e85 over petrol would have to be a good thing.

HHughes1

E85 allows for substantial power gains when tuning forced induction but the consumption will cost more than the price per gallon savings.

S.U. Vette

I think 99% of people that tune for E85 in a Corvette, do it for power and not fuel or cost savings.

badtbon

I have been running e85 in our Ultralight Z06 for 6 years now, problem free. Simple conversion to say the least. I also converted our 777 HP Katech CTS-V to alky, and run it in our SUV.

Our C7 seemed ready to go, with a tank fill-up trigger that does fuel enrichment to the tune of -30% LTFTs for a few minutes of initial driving until the O2s correct stoich back to 14.1:1.

Just a guess, but this trigger is likely a GM safety protocol for the guy that mistakenly fills up with e85, not a FF trigger.

The fuel type sensor must be onboard, but the ECM still has FF off. I did not want to experiment with e85 since our intent was to sell the car right after our R&D was over, so I left the ECM alone.

I will be tuning our C7Z06 for e85 unless GM decides to put that feature ON instead of off.

I predict that e85 and 15 PSI will be the rage next year. One pulley and e85 with its 33% oxygen and 105 Octane will light up your world. Pure ethanol contains 35% oxygen, so it helps keep us green and puts nice black marks down blacktop as a side benefit. In addition, our car has 13.2:1 comp ratio, and I run 26 to 27 degrees lead at full tilt, 610 RWHP/535lb-ft na and water temps never go above 179F. Oil temps are actually too cool at 185F, which is not even at viscosity rating.

I have been fascinated with alky motors since I was 14, using it in my Moped! Ironically, I am a non-drinker, my cars are not.

HHughes1

That was a response specifically for the OP who mentions fuel savings as a side benefit. I would chime in that 100% who tune for E85 do so for the aggressive timing available with 105 octane along with the cooling benefits of the ethanol.

Slow Poke

I should have clarified fuel savings cost referring to using E85 at 3-4 dollars per gallon rather than using unleaded race fuel at 8-10 dollars per gallon at the track. Most people realize E85 has less fuel economy but the performance of 105 octane and cooling effects more than offset the lower mpg. I don't care about loosing a few mpg, I am about extra performance with flex fuels.

It would be cool if the factory offered the flex fuel as an option so some of us who would like to keep the factory warranty in place would not have to tamper with reprogramming the ECM. That all I was saying.

PowerLabs

Fuel type sensors are very expensive; you can rest assured no factory vehicle has ever had them installed without being a flex fuel vehicle. In fact even flex fuel vehicles don't always have an ethanol sensor; they figure out the fuel by looking at the fuel injection amount vs O2 percentage in the exhaust...

bscot968

I have been giving much thought recently to alternative fuels, mainly in converting an LS powered Corvette. I would love it if GM offered an option for alternative fuels, mainly LPG(liquid propane) or natural gas(LNG). The cost savings, even considering the higher a/f ratio, have become much more substantial due to recent gasoline prices. But for myself and most other Corvette owners, this is not the main advantage. Power increase, particularly with a compressor engine, is a key advantage. But, what I have found the most overlooked advantage is the increased engine life. I am not sure if this may be an area that GM would consider, or if it is something that is available as a retrofit(for performance vehicles), but sign me up! With the U.S. having recently become energy independent in regards to natural gas, it would be a logical alternative to explore. It seems like more trucks and service vehicles are having great success with alt. fuels, why not performance cars?

johnglenntwo

If they were they wouldn't be talking only 650HP!

bscot968

Only 650hp? Seriously? Having spent years with "only" 520rwhp, and allowing a relative behind the wheel that thought the same, I question if you have been within 250hp of "only 650hp". BTW, my cousin does not see horsepower numbers the same, certainly does not regard over 500hp at the rear wheels in the same way.

johnglenntwo

My point is they could easily get a lot more on E85. The ZR1 didn't have it and....

GrantG

I think you are a little confused. Running E85 would result in a much slower car even if the mixture was adjusted to run it optimally, unless you did something in the aftermarket to increase the boost (different pulley, etc.). Since the supercharger is small for the power level on the C7 Z06, you'd likely need to add a bigger SC to benefit (stock one doesn't have much headroom), along with bigger injectors and dyno tuning.

E85 yields 33% less power per volume of fuel during combustion compared to gasoline. So, your 650hp Z06 would produce 433hp on E85 at stock boost level (maybe a little more when adjusting for the richer mixture, but way less than 100% gasoline).

http://en.wikipedia.org/wiki/E85

The high octane of E85 (as you mentioned) is only a benefit over gasoline when the engine is specifically designed to exploit it (like much higher than stock boost level in turbocharged cars, that would ordinarily make tons of detonation at that compression with gasoline). High octane just means resistance to knocking (detonation) with high cylinder pressure - it does not mean more powerful on its own.

I love E85 in my Evo IX (special injectors, boost controller, and computer mapping required to benefit), but would never use it in a normally aspirated or stock supercharged motor. Tuned turbos? Absolutely!

johnglenntwo

NO! You have to add more fuel not boost. And on a hot day you won't be pulling timing like gas.

GrantG

You can run as rich as you want, but at the same boost level you'll make more power with 93 octane gasoline on a stock C7 Z06

HHughes1

Tuned properly, E85 can make more power in both NA and supercharged cars where boost is not a variable. My track car is an FRS with a 2.0l flat four that made 160 at the wheels stock. With headers and exhaust and two switchable maps it makes 190 on 93 octane and 205 with E85. Same motor supercharged typically makes 275whp on a 93 tune and 325whp on E85 same boost level. Turbo setups are seeing 100+ whp difference in the fuels as boost is increased as well as the aggressive timing. Fuel pump and port injectors (this car has port and direct injection) are upgraded on most FI builds but not required for lower HP goals.

GrantG

Interesting - I can only conclude that the very high compression of that Flat-4 (12.5:1 I think) that uses DFI (as well as port injection - I believe it has both) is hampering the factory map intended for gasoline and that E85 allows a more optimal setup. On most NA motors with more common compression (say less than 10:1), E85 will suffer in output compared to gasoline.

On a low compression motor (say 8.5:1), the results are really poor for E85.

On my Evo IX, I run 4 psi more boost and lots more timing with E85 and get over 100hp and 100 ft-lbs more with E85 compared to 91 octane gas. I've never heard of good results with E85 in an NA car (unless the compression was custom built super high - beyond the point where you would run pump gas). Interesting that today's modern gasoline motors that run really high compression can benefit from E85...

jsiddall

Sorry, have to disagree here. My stock [long block] '85 with a 9:1 CR runs fantastic on E85 with slightly more power than gasoline. If you tune it right (i.e: add lots more E85 than gas) there is no reason any engine cannot make more power with it. Although ethanol has lower energy density than gasoline (30 MJ/kg for ethanol vs 46.4 for gasoline = 64.7%) it also has a a much higher stoichiomentric mass (14.7:1 for gasoline vs 9:1 for ethanol = 163% mass) resulting in a net potential power increase of 64.7% * 163% = 105% compared to gasoline.

jsiddall

The exact opposite thing happened to me recently. I converted my early C4 to E85 years ago including doubling the injector flow. Recently I needed to make a couple of long road trips so I re-mapped the PCM for gas. However, due to a bug in the tuner the change to the fuel table was not saved so it was still adding E85 amounts of fuel with gasoline in the tank. Although it idled horribly rich once it hit closed loop the PCM cut the right amount of fuel and it ran fine on pure gasoline. I was surprised to see the BLMs could go low enough to compensate for a fuel change.

PowerLabs

4 reasons off the top of my head why they don't:
1- There is nowhere to put the massive tank (it can't go in the trunk because that is connected to the cabin:

2- It doesn't make any sense. A typical LPG vehicle goes ~150 miles on a tank like that before it has to be refiled. Where are you going to fill up your LPG powered Corvette?
3- There are no direct injectors in the market right now that can handle natural gas / propane. There are no injectors capable of flowing enough natural gas to match the specific output of an LT4 either.
4- The HP rating would be a lot lower, since the gas displaces air and lowers engine volumetric efficiency.

E85 would make more sense, but it is nowhere near popular enough to justify the cost of implementing it on a Corvette.