Searya

Wondering if anyone has converted to E85 on an LS7 and what the pros and cons are?

I have a 12.5 to 1 LS7 and have been thinking about running E85 and a single tune versus having a track (race fuel) and then daily driver (93 octane) tune.

1991Z07

HallTech did one...here is the thread on it.

http://forums.corvetteforum.com/c6-z...c-for-e85.html

Racingswh

Looked at it very seriously 2 years ago. Problem for me was fuel consumption. Just too much to have to transport to tracks without any e85 stations close to the tracks I run at. It will use 40% more fuel. The car I was looking at was an 06' Z06 making 590 rwhp. Looked awesome. Ran great. Just couldn't do the fuel quantity at the track it would have required.

RX-Ben

great idea in theory. Fuel consumption means you are going to need a serious fuel system.

Screamin Z

pros to running E85.

Handles higher compression
Burns cleaner than gas
Cooler cylinder temps
Cheaper than 105 race fuel.

Cons.
Consumes 25% more for same power
Availability.

Have been running on E85 for about 3 years now. Tons of smooth power and motor runs cool on 100+degree days. If I venture out to the east cost I pack along 100 gallons of fuel.

Between two drivers we can eat up 60 gal of fuel a weekend. Depending on the track. And that's with a 600+rwhp setup.

phxcobra

Just injectors and possibly fuel pump. I did both although I probably could have gotten by with the stock fuel pump. Did the pump for safety margin as I was really pushing it.

Racingswh

That's exactly what I was figuring and 3 track days double dutied between my wife and I the 110 gallons of E85 didn't seem like it would be enough to get us thru Sunday. Also carrying 700 lbs of fuel with me in the trailer wasn't exciting me all that much.

I can tell you this. If I could have driven the car or ran out with fuel jugs to an E85 pump within a reasonable distance to even some of the tracks we run at I would have been able to justify the purchase and done it. Lot's of positives if availability isn't an issue. For me it was the deal breaker at the time.

Gman57

..... and fast!!
Hope all is good.

G

Screamin Z

Things are good! I trashed 3rd gear on the second day at Topeka. New RPM Transmission went in. Haven't had a chance to try it out yet. But pops said it tough to shift.

RX-Ben

check shifter alignment. Very finicky.

1991Z07

Don't know who you talked to...but 40% more fuel is way off the mark.

Jim Hall reported his Katech E85 LS7 with the higher C/R to take advantage of the octane rating of the E85 got 12%-14% lower mileage than a comparable gasoline powered LS7.

This is the thing most people don't get...to run E85 in an engine designed for 93 Octane gasoline you will never get the full potential of the E85. Build the motor for E85 and the results are completely different. You can safely go to about 13.5:1 for 105 octane, and you get the added cooling factor of the alcohol on the motor as well.

Racingswh

It was Fran at RPM who built the E85 motor. That's who I spoke with as he and I discussed what the car would be used for. The comparison was being made between a stock 505 HP LS7 and the 590 rwhp LS7 powered Z06 he had specifically built to run on E85.

If for some reason now my wife and I share her car at an event (436 hp) we go through two tanks of fuel per day minimum which is about 90 gallons or so for a 3 day weekend. Just didn't see how we were going to make it through a weekend with just a full tank and another 110 gallons of alcohol in the trailer.

I imagine we can agree that even using conventional fuel a 590 rwhp LS7 would use significantly more fuel a WOT than the stock LS7 and that in the E85 configuration it would use even more.

TJM

Not what we saw. 25%-30% more fuel needed.

Other Cons:

* Consistency, Blends change 70% in winter in Ga.
* Stuff will absorb H20 like a sponge[ it IS Dry Gas].
* Will wash cylinder walls and oil needs to be watched.
* WILL destroy rubber, though not instantly.

Intend to continue to use it, have our drill down and bugs worked out.
and because here it is available at $3.33 a gallon.

The consistency issue is pretty easy to overcome. There is a $10.00 tester to measure % of alcohol in E85 and sweetening is a simple trip to ACE hardware.

TJM

We have to tote a 55 gallon drum, but we have a local source so it is a minor aggregation.

Screamin Z

And that would be?

Ive seen anything from 70%-90% out of the pump

TJM

a gallon of denatured alcohol [ @ $16.00 - $17.00] is 5% enrichment in a 20 gal tank... .. pricey way to do it..

just sayin...........

Gman57

This is why my builder poo pooed E85 when I asked about it Last year.

RX-Ben

Right, you will need to test basically every time you fill up and then adjust as necessary. You can improve on this a little bit by carrying around (nearly) pure ethanol and cut it with 93 octane to get your desired mix, but you will still need to test your mix every time.

Werks

I've been running E85 for nearly 2 years now without problems. Fuel blends fluctuate in certain area's due to winter or summer blends. Where I'm at (CA) we only use 1 blend year round, so no issue there and I have never experienced (or I should say noticed) any tune related issues from pump fluctuations. Having said that though with my new engine the builder did go with a more conservative 13:1 compression ratio instead of 14:1 to allow for it

Drazga

My 09 C6Z06 (H/C/I) has a FlexFuel sensor so it is tuned for 93<->E85. The GM flexfuel/ethanol sensor determines the ethanol content in the fuel line and then there is a set of algorithms that determine the timing and fuel maps. The car had to be tuned from 93 (E10) in increments all the way up to E85 but its totally worth it since I don't have to run multiple tunes or drain my tank. I usually fill the tank with E85 before I load it on the trailer and bring five VP Racing Fuels 5 gallon jugs that I fill up at my local pump before heading to the track. The power gains are minimal since the car is stock motor (bottom end) but every little bit helps not to mention the cooling benefits.