E85

[XfireZ51]

For those of us that have been following the C7 saga, there's been lots of chatter over the use of E85. Some have shown dynos +40whp with a tune.
For the most part it sounds like using E85 is a matter of tuning for E85. Not much else required at least when it comes to C6. More timing, more compression w no knock. The LT5 is not timing limited, you just lose power.
Any thoughts?

[USAFPILOT]

I wish someone would give it a shot, male it work and then tell everyone else how to get it done. We should be able to make more power on E85, but at what cost. Surely that stuff is going to ruin something. E10 already caused me to buy new injectors.

[mike100]

I guess you won't get the benefit of more ignition timing power with the LT5 ( ? maybe), but the air charge might come in cooler and it won't ping under load on hot days.

mainly though, Alcohol fuels should make more HP than gasoline. Gas actually has more btu content per gallon or by unit of weight, but you can burn a lot more alcohol than gasoline for any given volume of air. So there is a certain percentage of gain there if the engine takes advantage of the A/F ratio at 9.7:1 for E85. Also alcohol fuels are an oxygenate so I guess they burn completely and can get away with the richer mixture. I know blown alcohol cars run in the 4.5-6 to 1 air fuel ratio, but E85 is a lot less crazy than that so I don't know exactly how the math works out on btu per lb of fuel.

12:1 compression stroker LT5's would love e85 I bet. I would be willing to bet the ignition timing characteristics of E85 on the LT5 would be a little different anyhow. 100 octane equivalent burns slower so a lot of lead (29-30 degrees maybe) might actually make more HP. Double injectors sized right might really work well for E85. I can buy this fuel down the street- it would be interesting to find out.

As far as the C7 application, the vvt action on the cam can really have an early intake valve closing and spike the compression for torque with the E85.

[Hog]

The GM flexfuel truck have 2 power/torque ratings, 1 for gas, 1 for E85.
The 2010+ 5.3 LC9 truck engine is rated at 315hp@5200rpm/335lb/ft@4000rpm on gas.
On E85 the LC9 is rated at 326hp@5300rpm/348lb/ft@4400rpm on E85.
These are using the newer "Certified Power" that the GEN 4 LS7 was rated with.

With direct injection you can also now inject fuel no matter where the piston is.
DI injectors that have the capacity to be used with E85 will be a hot item for modifiers of C7's for use with gasoline. Just like guys installing low boost forced induction on flexfuel vehicles for use with gas without needing larger injectors.

The gains on an LT5 would be similar to the results of meth injection. The real advantage would be when adding forced induction from a turbo/supercharger. There would be more advantage if the alcohol was injected furthur ahead in the airstream, like just behind the t-body.

Stoich for E0(100% gas) is 14.7:1
E10 is 14.2:1
E85 is 9.7:1
E100 is 9:1(100% ethanol is impossible to attain with "normal" distillation.

Mike 100% Methanol has a stoich ratio of 6.47:1, so the blown alchy cars running from 4.5:1-6:1 would be right to keep the engine together. Those cars have the injection hats and intakes develop ice/frost on them from the methanol.

40+rwhp gains, I could easily see that in a blown application
.
peace
Hog

[XfireZ51]

Hog,

The LT5 cal allows you to modify STOICH or what the ECM should consider as stoich. Because of the 10% Ethanol here in Illinois, I have it set at 14.3 rather than 14.7. It could be running rich if I ever get pure gas, but I haven't found anywhere around here that doesn't have 10%. So is it a matter of making sure the injectors can live w E85 and tuning for that?

[Hog]

Yes, once you have compatible injectors, that will tolerate alcohol and are large enough for the added volume requirements of alcohol, ECM tuning is all you would need.

There can be problems when vehicles have accumulated age and miles where contamination can build up in the fuel tank. Then when E85 is added, this contamination can become mixed up in solution and carried through the fuel system.
I have looked inside quite a few fuel tanks of trucks/cars from the mid 90's and they have APPEARED very clean.
If the system is clean and parts are compatible, there shouldnt be an issue.

peace
Hog

[rkreigh]

I need a chip burned for E85 just to pass emissions.

to really make e85 work, you'll need bigger pumps, injectors, making sure the fuel system won't erode with alchy (some stuff will) and of course the more compression helps

12-1 runs just fine on pump gas with the lt5 because of the very efficient combustion chamber and dished piston.

advancing the timing really won't do all that much. you need more cyl pressure!! by eliminating any detonation, bumping up the timing, and of course the cooler fuel with higher octane you'll bump up the power but don't expect 40 hp without optimizing the engine to run e85

I think 13 or 14 to 1 compression would be about where you need to be to really gain a bunch.

just remember alchy doesn't have as much zots as gas so you need to pump a whole bunch more of it!!! probably a pair of 42 lb injectors would do it and a pair of bigger 340 or so pumps to provide enough volume.

I don't really know exactly what else would need to be replaced but any of the rubber in the fuel system would need to go. the zr-1 looks to be mostly metal front to rear. alchy loves to soak up water and can't sit as long as gas before it goes sour

I have an old alchy drag car and quite frankly, its a big PITA (pure alchy)

I'm thinking about retuning it for e85 just to make it easier to start. I have to gas prime it and run a "warm up circut" on gas now just to get enough heat in the motor to make a pass by leaning it out.

not to discourage you, e85 is the stuff !! it has some tremendous potential, but more so on turbo/blown forced induction.

It would be interesting to see what could be gained on the LSV. I'm guessing around 20 hp tops (probably closer to 10)

on a stock zr-1, 10-15, not too much more. you could more easily find out by running an alchy injection system. see the other thread. much more feasible and you would get most of the gain by cooling down the mixture and getting a bit more fuel into it. all of it would require some tuning to make it work though might be more trouble than it's worth as the lt5 works just fine on 93 octane.

I ran race gas at that track with a LPE chip with more timing, didn't make any more power. but the car will pull 128 up top on regular ol 93 octane so it's getting all 508 to the ground at that point

[XfireZ51]

Ron,

Lot of discussion about E85 with the new C7 so I thought I would start a thread here. Not sure if anyone ever attempted this. Has Corey thought about it or
SGC? I recall Leno doing an E85 conversion on a C6 Z06. Would be interesting to find out.

[rkreigh]

I talked to Corey over a year ago about tuning the car for E85 strictly to help it pass the tough VA emissions. with the big cams, and no secondaries I couldn't get the HC down low enough (it's way off, 140 HC on a 48 standard)

I also wanted to use an exhaust gas analyzer to make sure it would pass.

Corey definitely thought it could help.

from what I understand the ZR-1s will flow enough for 700 hp using normal gas so you might be able to have enough volume to tune a stock car on E85 without running too lean. (not go over 500 hp to be safe)

I'd feel safer with at least upgrading the pumps.

worth talking to corey again. too far for me to drive down to texas, so I was hoping to do a chip with Bob Hall's car which is built very similar to mine. but now that car is up here with me in VA.

Might be able to do a remote tune working with folks up here and going back and forth. it would likely take a few burns to get it right.

[Schrade]

Wouldn't the alcohol burn a little hotter?

Is Mr. Haibeck's new chip coded for higher alcohol mix? Pg 15 of his write-up says OE AFR is rich???