E85 Conversion

[LGAFF]

Anyone done E85 in their Z yet, seeing some good results posted for NA motors.

[FU]

See the 368 on E85 on the Corvette forum that is for sale ?

[LGAFF]

I was looking at some of the LS1 Results .....20-30hp pickup

[FU]

http://www.corvetteforum.com/forums/c4-zr-1-discussion/3864230-fs-1990-zr1.html

That car is local for me. The builder SK Speed shop is well known. There must have been a heck of a tuner or a different EMS used to tune that setup. I knew the previous owner , then it had a bad engine. Long story.

[XfireZ51]

Very likely need bigger injectors along w fuel pumps to support them.
Then separate tune for e10 v e85. Be nice to have a Flex Fuel sensor along w programming to support it w our ECM.

[LGAFF]

Very likely need bigger injectors along w fuel pumps to support them.
Then separate tune for e10 v e85. Be nice to have a Flex Fuel sensor along w programming to support it w our ECM.



wouldnt be opposed to doing that but with 16 injectors and 2 pumps its not enough?

[Billy Mild]

Need a more modern ECM to control it.

[BigJohn]

The nearest E85 pump is 2-1/2 hours away from my house.

[Hog]

Need a more modern ECM to control it.
To control what?

Going straight E85 would be straightforward with the stock ECM with a calibration change.

E85 at the pumps does vary quite a bit, unlike the E85 you can buy by the drum, which is actually 85% Ethanol 100% of the time.

[tpepmeie]

The only reason I can think of that you'd *need* a new ecm is if you wanted to run different blends of E85 and unleaded. Then you'd need a flex fuel sensor and the ability to modify the fuel pulse for varying stoich ratios.

Other than that the stock ecu would work fine, with the proper calibration.

I come back to Lee's original question and I don't know why one would do this on a naturally aspirated engine. There is much less energy in a gallon of ethanol compared to pump gas so I can't fathom how it makes more power normally aspirated. Now if you're running boost and can benefit from the charge cooling effect then ok. But that's not the situation that was proposed.


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[Hog]

Just to see what GM is doing with their new engines on the Flex-Fuel front.
I do see that the newer K2XX trucks from 2014+ are running the new GEN-V SBC with direct injected Ecotec-3 engines, some are flexfuel like the L83 5.3 and the LV3 4.3 liter V6. I included the L86 6.2, even though it isn't a Flexfuel engine just to show how well these newer Durect Injected engines do.
L83-5.3 355hp @ 5600rpm/383 lb·ft @ 4100rpm on gas
376hp @ 5600rpm/416 lb·ft @ 4000rpm on E85
21hp/33 lb/ft torque gains in SAE ratings using E85 the L83 5.3 uses an 11:1 compression ratio

L86-6.2 420hp @ 5600rpm/460lb·ft @ 4100rpm
The L86 6.2 liter/376cid runs a 11.5:1 compression ratio, this is the truck version of the C-7 Stingray's engine. They are both GEN-5 SBC's.


Even the LV3 V6 does better on E85. This V6 has an 11.0:1 c/r.
285hp @ 5300rpm/305lb·ft @ 3900 rpm
297hp @ 5300rpm/ 330 lb·ft @ 3900 rpm on E85Gains of 12hp @5300rpm/25 lb/ft torque @3900rpm on E85.

With these truck engines, I'd bet that there is some ECM tuning funny business at play here. GM supplies vehicles with Flexfuel engines to make the Gov happy, and then tunes them slightly more aggressive when E85 is in the tank so that folks will buy them and then choose to burn E85. This keeps the farmers happy to supply the ethanol plants. The Gov. then backs off on corn subsidies.


As to Todds response, agreed in a true N/A E85 to gas compare with ECM tuning optimized for BOTH gas and E85, the E85 should show less power. To see a power advantage while running E85 in a N/A setup would require an increase in compression. In doing so, your engine would from that point forward be a race gasoline or alcohol/E85 only engine due to the increase in compression.

[LGAFF]

So if you search the net a lot of NA Cars making significant increases in power 20 to 30hp. Illinois also has a significant # of stations with E85



http://www.superchevy.com/how-to/vemp-0801-corvette-e85-conversion/

Alot of LS engines conversions with similar results and NA.....

[Kevin]

make sure you change out the fuel lines too

[LGAFF]

Even a stock Coyote with an air intake and exhaust as the only mod made about 12-14rwhp on just switching to E85

[LGAFF]

https://www.youtube.com/watch?v=cT_3JLg7KeA

[LGAFF]

I will put E85 Conversion on my list for late 2017:)

[XfireZ51]

So if u run a straight E85, then the changes to the calibration are fairly straight
forward. You will need to confirm that u have the fuel delivery necessary since u r going from 14.7 to 9.0:1 AFR for stoich. That's about 30-40% more fuel.
The change involves the injector constant, stoichiometric air/fuel ratio, and tweaking of the VE tables and timing. BOTH the injector constant and command stoichiometirc air/fuel ratio constants affect the pulsewidth substantially. You'll need to confirm that the existing fuel system will accomodate the increase in fuel flow required. By adjusting the stoichiometric air/fuel ratio you are adding the proportional amount of pulsewidth automatically. Same goes for the injector constant, when you increase the value the pulsewidth decreases. Both are global changes in fuel delivery, which means small tweaks to the VE tables.
It would be nice to have code incorporated as part of our calibration to utilize Flex Fuel sensor data to affect the stoich etc so as to automatically accomodate
variation in the ethanol content. Otherwise it becaomes a matter of
switching bins for the appropriate ethanol content.

[LGAFF]

Dominic it seems to me the Z already has the pump/inj capacity to run both....could you not just swap proms if need be to move back and forth between fuels?

[BigJohn]

Do you need stainless fuel lines?

[LGAFF]

Classic tube has them, about $250 for everything....swap out all orings

[XfireZ51]

Dominic it seems to me the Z already has the pump/inj capacity to run both....could you not just swap proms if need be to move back and forth between fuels?

Based on BSFC calc, the stock fuel system supports 537-572 hp depending on whether ur using 80 or 85% duty cycle on the injectors and assuming the injectors each flow 21#s/hr. So the heads/cams stock block modded motors are already close to the edge on the fuel system. Should be ok for stock motors. Then it becomes an issue of whether u r running E85 all the time or end up blending fuels which is where the fuel sensor comes in.

[Hog]

Some States run a Winter blend of E85 which is actually 70% Ethanol to help with cold starting encountered when ambient temps are low.

I would think that a few PROMs for a few different Ethanol compositions would work great for these differences. As X-Fire suggests, code to incorporate an Ethanol Composition Sensor would be ideal, but that's not going to happen anytime soon.

There seems to a variety available test kits that will give you the percentage of Ethanol to gasoline. Fill your tank, snatch a fuel sample, determine alcohol percentage, select appropriate PROM, away you go.
I haven't looked into any of these, just the results from a quick search on Ebay.
http://www.ebay.ca/sch/i.html?_nkw=ethanol+test+kit

[LGAFF]

Interesting comment, my TT V12 developed a misfire running winter blend, apparently a common issue in the Midwest with this engine.

[XfireZ51]

Maybe installing a Flex Fuel sensor and connecting to some sort of gauge for immediate readout. Then using a Prom Emulator like an Ostrich to download a pre-done calibration for the Ethanol content currently being used. Might think about calibrations in increments of 5-10% of ethanol content.
Obviously, this isn't for a daily driver and assumes the necessary fuel system capacity.

[Hog]

That Alcohol percentage readout from an alcohol sensor is a great idea, then you can adjust from that.

Question.
In the LT5 calibration is the IFR(Injector Flow Rating) 22.7lb/hr?

And the stock FPR holds rail pressure to 50.8psi at WOT. I was just running some fuel calcs and wanted to ensure I was using the correct base numbers.

Thanks.

[XfireZ51]

That Alcohol percentage readout from an alcohol sensor is a great idea, then you can adjust from that.

Question.
In the LT5 calibration is the IFR(Injector Flow Rating) 22.7lb/hr?

And the stock FPR holds rail pressure to 50.8psi at WOT. I was just running some fuel calcs and wanted to ensure I was using the correct base numbers.

Thanks.

Yes, its 22.7# altho I'm not so sure the stock injectors actually flow that. I had the Accels flow tested and they came in at ~ 20.7# @ 43psi.

[Hog]

Yes, its 22.7# altho I'm not so sure the stock injectors actually flow that. I had the Accels flow tested and they came in at ~ 20.7# @ 43psi.

So that 20.7lb/hr @ 43.5psi becomes 22.4 lb/hr @ the LT5's 50.8psi rail pressure.

Thanks for the confirmation.

[Hib Halverson]

An E85 converted first-gen LT5?
Seriously?!

The cost of the conversion to gain a small power increase would be obscene.

You'd likely have to change:
Fuel tank
Fuel pumps
Fuel lines
injectors
and, of course, calibration.

You'd also have to add an ethanol sensor in the system because virtually no pump E85 is consistently 85% ethanol. The proportions of alcohol in pump E85s vary widely. The only E85s which are consistent are racing blends such as Rockett Brand Racing Fuel's "E85 112".

You'd also have to add some alternative engine controller capable of varying the injector duty cycle according to the ethanol sensor's data.

[LGAFF]

An E85 converted first-gen LT5?
Seriously?!

The cost of the conversion to gain a small power increase would be obscene.

You'd likely have to change:
Fuel tank
Fuel pumps
Fuel lines
injectors
and, of course, calibration.

You'd also have to add an ethanol sensor in the system because virtually no pump E85 is consistently 85% ethanol. The proportions of alcohol in pump E85s vary widely. The only E85s which are consistent are racing blends such as Rockett Brand Racing Fuel's "E85 112".

You'd also have to add some alternative engine controller capable of varying the injector duty cycle according to the ethanol sensor's data.

Its been done successfully by other C4 Owners....you don't need to go to the extreme that you have listed, pumps...tanks do not need to be changed, and I do my own work....so not a big deal or expense. I am at 441RWHP NA so looking for options as hitting the limit....and then theres the 75 shot of nitrous

[rkreigh]

The only reason I can think of that you'd *need* a new ecm is if you wanted to run different blends of E85 and unleaded. Then you'd need a flex fuel sensor and the ability to modify the fuel pulse for varying stoich ratios.

Other than that the stock ecu would work fine, with the proper calibration.

I come back to Lee's original question and I don't know why one would do this on a naturally aspirated engine. There is much less energy in a gallon of ethanol compared to pump gas so I can't fathom how it makes more power normally aspirated. Now if you're running boost and can benefit from the charge cooling effect then ok. But that's not the situation that was proposed.


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emissions. and of course upping the compression and still running cool. E85 is good stuff. But as Todd points out, it's really not worth the cost (new pumps, injectors, calibration, fuel filters, really the whole fuel system) to gain a few ponies.

However if you are going to boost it, or go super high compression, it might be worth it.

For me I'd love to try it to clean up the HC. The LSV has bad breath and HC are still up above 120 on a 48 standard.

Some fresh cats MIGHT clean it up enough, but I'm going E85 on the turbo car so the LSV might like a drink too.