E-85 Max Wedge

[dieseldazzle]

I read your links - pretty damn impressive! I've been thinking about E85 combos lately and have a few thoughts/questions that I'd love to hear your take on:

Your combo was 14.5:1 CR; what do you think a good rule of thumb CR limit for E85 is?

Also, I have been toying with the idea of building an engine set up for both race gas and E85 utilizing Holley's HP Dominator EFI (E85 compatible). Drive on the street with E85 and a compatible tune on the EFI/ignition. When you want to turn up the heat, run the tank down to empty then fill with 104 race gas - run the electric pump (engine off) and bleed the E-85 from the fuel rails. Re-squirt the EFI control module with the 104 race gas tune, fire it up and head to the strip.

You could conceivably do the same with carbs, just needing 2 different carbs you'd swap between fuels.

Thoughts?

I don't understand why you would want to ditch the e85 when you "turn it up"??

I've built single turbo 327 inch small block ford out of my garage that made 960hp to the tire on e85. It is sometimes driven on the street and the pump e85 has always tested great with the analyzer.

My buddy runs the same setup on his Lsa stroked cts v Cadillac daily, no issues.

 

[GrabberOrange69]

I don't understand why you would want to ditch the e85 when you "turn it up"??

I've built single turbo 327 inch small block ford out of my garage that made 960hp to the tire on e85. It is sometimes driven on the street and the pump e85 has always tested great with the analyzer.

My buddy runs the same setup on his Lsa stroked cts v Cadillac daily, no issues.

Well, I'm thinking race gas for more power. Gas has more BTU's per gallon so my thinking is if the compression ration is the same, gas would be more power. E85 is sexy because it tolerates high compression ratios and is cheap, but if the gas you're running can handle the same CR, it should make more power.

From the interweb - "1.5 gallons of ethanol has the same energy content as 1.0 gallon of gasoline. The energy content of 1.0 US gallon of ethanol is 76,100 BTU, compared to 114,100 BTU for gasoline"

 

[dieseldazzle]

Well, I'm thinking race gas for more power. Gas has more BTU's per gallon so my thinking is if the compression ration is the same, gas would be more power. E85 is sexy because it tolerates high compression ratios and is cheap, but if the gas you're running can handle the same CR, it should make more power.

From the interweb - "1.5 gallons of ethanol has the same energy content as 1.0 gallon of gasoline. The energy content of 1.0 US gallon of ethanol is 76,100 BTU, compared to 114,100 BTU for gasoline"

I'm not any kind of fuel scientist but from what I understand there are also cooling characteristics with e85 when combusted which should aid in making more power with being able to get away with more timing in an internal combustion engine and in turn making more power but then again that's only my small small understanding of it all.

 

[dieseldazzle]

While I'm thinking about it I do know that too much octane can be a bad thing so maybe you are correct.

I know my 9:1 naturally aspirated motor made more power on pump 91 then it did on 104 race fuel....but once I added 215hp nitrous the race fuel made it a monster so I'm kinda with you so far.....

 

[SwedCharger67]

Well, I'm thinking race gas for more power. Gas has more BTU's per gallon so my thinking is if the compression ration is the same, gas would be more power. E85 is sexy because it tolerates high compression ratios and is cheap, but if the gas you're running can handle the same CR, it should make more power.

From the interweb - "1.5 gallons of ethanol has the same energy content as 1.0 gallon of gasoline. The energy content of 1.0 US gallon of ethanol is 76,100 BTU, compared to 114,100 BTU for gasoline"

If you compare the BTUs...why is nitromethane giving such huge power numbers in dragsters???? Nitromethane has very low BTUs, but AFR=2...i.e. lots of fuel injected, way more than any gasoline fueled engine can take, and way more BTUs...

Basically the same with E85, lower BTUs than gasoline but AFR=7-8, i.e. more E85 injected than possible with gasoline...adding up to more BTUs than possible with gasoline.

 

[GrabberOrange69]

If you compare the BTUs...why is nitromethane giving such huge power numbers in dragsters???? Nitromethane has very low BTUs, but AFR=2...i.e. lots of fuel injected, way more than any gasoline fueled engine can take, and way more BTUs...

Basically the same with E85, lower BTUs than gasoline but AFR=7-8, i.e. more E85 injected than possible with gasoline...adding up to more BTUs than possible with gasoline.

You may be right and that may be the key.

BTW I believe Nitro is 3:1 AFR...Not that it matters.

Update: I did the math, and if it's correct, 12.5:1 Gas – 114,100/12.5 = 9128 BTUs per volume, 8:1 Gasohol – 76,100/8 = 9512 BTUs per volume. I think the keys are gasohol is 85% gasoline (high BTU content) while the alcohol raises the tolerance for higher compression allowing more power, plus just like Nitro, the gasohol charge mixture is likely much cooler - which is denser.

Maybe just straight E85...

 

[70bigblockdodge]

Nitromethane is in some ways similar to diesels just keep adding more fuel and more oxygen and they keep making more power. A/F ratio on both (diesel and nitro) is not a rule but a this is where it was at at X horsepower number. Gasoline is a finicky fuel that makes its power at a very narrow air fuel ratio (too rich= bad, too lean= bad).

 

[dvw]

We run it on the street under boost. If the car is used regularly (once a week) corosion is a non issue. [email protected] compression with no intercooler. Fuel economy is poor, still cheaper than race fuel.
Doug

 

[crossram 426]

E-85 is 107 octane rating in Australia.