EGT's lower with E85 vs. 93 octane?

[V6UnderPressure]

Simple question....or is it?:biggrin: E85 burns cooler correct? Just curious what the higher end of the EGT's at full throttle would be compared to say 93 octane.

 

[Rafs-T-Type]

ttt I'm quite curios as to the answer

 

[charlie]

I would say the right person for this question would be eric from turbo tweak if he doesn't answer it here you may want to post it on his sight.

 

[charlief1]

I'd like to know myself.

 

[pwr6kid]

I know from sprint car racing that you can heat or cool the motor with the amount of alcohol. More fuel=cooler less=hotter. As for egt's I would think they would go down with more fuel since the motor is running cooler. This is with strait alky not E85; since E85 is 85% alky I would think it’s the same principal. If I’m wrong please correct me as I would like to know too.

 

[Hot Air]

Let's not confuse ethanol with methanol! I have not heard anything about combustion temperature being less with ethanol. I will do a little research and get back to everyone.
Conrad

 

[pwr6kid]

Thank you for pointing that out, I didn’t realize that I had the two mixed up.

 

[bison]

Latent heat of vaporization is a little less than methanol with ethanol. So it will cool on vaporization almost as well but not as much as methanol. E85 is not all ethanol. Its up to 85% ethanol. You never know for sure the exact %. It would burn similar to M85 though. If your EGT's were low then you are too rich. There are more variables to consider when determining what will happen with EGT's. Timing retard will increase EGT. You should still target roughly the same EGT's as with gasoline but the a/f will be considerably different because of the different heat value of the E85. You could run a slighly lower EGT and not lose as much power as you would with gasoline which has a smaller window for peak power. The highly oxygenated race fuels like Q16 have a broader window for a/f also.

 

[bison]

since E85 is 85% alky

No. E85 is not 85% alky all the time. Its up to 85%. This is why you should leave a little room for fuel variation on your tune. If you were mixing ethanol from a sealed pail with gasoline from a sealed pail so that it was 85% then you could be sure its 85%. You cant be sure at the pump. Probably more like 70-75% from most of what i have read. I have no exact data though.

 

[bison]

Latent heat of vaporization of different elements and compounds:
Fluids - Latent Heat of Evaporation

Keep in mind that if it has a lower boiling point is a combustible fuel and a high LHV it will be more effective in the cylinder. This is why alcohols are so good.

 

[MrMNTTA]

Here's a little info I have, maybe this will shed some light on the 'blend' of E85 at various places throughout the country. I hope this helps.

The below regional chart refers to the 3 classes of E85 blends that are offered in a particular area at that time of year. Each class has different properties, the most important being the amount of Ethanol in the blend which can affect the Air/Fuel ratio of your customized tune if you've converted to E85. This chart represents the recommended fuel to retailers, not necessarily what's in the tank at your local station.

Please be sure to read our E85 Tuning article regarding how this plays a factor.
Summer Blend: Class 1 (min 79% ethanol)
Spring/Fall Blend: Class 2 (min 74% ethanol)
Winter Blend: Class 3 (min 70% ethanol)
State Fuel Region Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Alabama 2 2 2 2 2/1 1 1 1 1 1/2 2 2
Alaska Southern Region 3 3 3 3 3/2 2/1 1 1/2 2/3 3 3 3
Alaska South Mainland 3 3 3 3 3/2 2/1 1/2 2 2/3 3 3 3
Arizona North of 34 latitude 3 3 3 3/2 2 2/1 1 1 1/2 2/3 3 3
Arizona South of 34 latitude 2 2 2 2/1 1 1 1 1 1 1/2 2 2
Arkansas 3 3 3/2 2/1 1 1 1 1 1/2 2 2/3 3
California North Coast 2 2 2 2 2 2/1 1 1 1 1/2 2 2
California South Coast 2 2 2 2 2/1 1 1 1 1 1/2 2 2
California Southeast 3 3/2 2 2 2/1 1 1 1 1/2 2 2/3 3
California Interior 2 2 2 2 2 2/1 1 1 1 1/2 2 2
Colorado East of 105 longitude 3 3 3 3/2 2 2/1 1 1 1/2 2/3 3 3
Colorado West of 105 longitude 3 3 3 3 3/2 2 2/1 1/2 2/3 3 3 3
Connecticut 3 3 3 3/2 2 2/1 1 1 1/2 2 2/3 3
Delaware 3 3 3/2 2 2/1 1 1 1 1/2 2 2/3 3
DC 3 3 3/2 2 2/1 1 1 1 1/2 2 2/3 3
Florida North of 29 latitude 2 2 2 2/1 1 1 1 1 1 1/2 2 2
Florida South of 29 latitude 2 2 1 1 1 1 1 1 1 1 1/2 2
Georgia 3 3 2 2/1 1 1 1 1 1 1/2 2 2/3
Hawaii 1 1 1 1 1 1 1 1 1 1 1 1
Idaho 3 3 3 3/2 2 2 2/1 1/2 2 2/3 3 3
Illinois North of 40 latitude 3 3 3 3/2 2 2/1 1 1 1/2 2/3 3 3
Illinois South of 40 latitude 3 3 3 3/2 2/1 1 1 1 1/2 2/3 3 3
Indiana 3 3 3 3/2 2/1 1 1 1 1/2 2/3 3 3
Iowa 3 3 3 3/2 2 2/1 1 1 1/2 2/3 3 3
Kansas 3 3 3 3/2 2 2/1 1 1 1/2 2/3 3 3
Kentucky 3 3 3/2 2 2/1 1 1 1 1/2 2 2/3 3
Louisiana 2 2 2 2/1 1 1 1 1 1 1/2 2 2
Maine 3 3 3 3/2 2 2/1 1 1/2 2 2/3 3 3
Maryland 3 3 3/2 2 2/1 1 1 1 1/2 2 2/3 3
Massachusetts 3 3 3 3/2 2 2/1 1 1 1/2 2 2/3 3
Michigan Lower Peninsula 3 3 3 3/2 2 2/1 1 1/2 2 2/3 3 3
Michigan Upper Peninsula 3 3 3 3 3/2 2/1 1 1/2 2 2/3 3 3
Minnesota 3 3 3 3 3/2 2/1 1 1/2 2 2/3 3 3
Mississippi 2 2 2 2/1 1 1 1 1 1 1/2 2 2
Missouri 3 3 3 3/2 2/1 1 1 1 1/2 2/3 3 3
Montana 3 3 3 3 3/2 2 2/1 1/2 2/3 3 3 3
Nebraska 3 3 3 3/2 2 2/1 1 1/2 2 2/3 3 3
Nevada North of 38 latitude 3 3 3 3/2 2 2 2/1 1/2 2 2/3 3 3
Nevada South of 38 latitude 3 3 3/2 2 2/1 1 1 1 1/2 2 2/3 3
New Hampshire 3 3 3 3/2 2 2/1 1 1/2 2 2/3 3 3
New Jersey 3 3 3/2 2 2/1 1 1 1 1/2 2 2/3 3
New Mexico North of 34 latitude 3 3 3 3/2 2 2/1 1 1 1/2 2/3 3 3
New Mexico South of 34 latitude 3 3 3/2 2/1 1 1 1 1 1 1/2 2/3 3
New York North of 42 latitude 3 3 3 3/2 2 2/1 1 1/2 2 2/3 3 3
New York South of 42 latitude 3 3 3 3/2 2/1 1 1 1 1/2 2 2/3 3
North Carolina 3 3 3/2 2 2/1 1 1 1 1/2 2/3 3 3
North Dakota 3 3 3 3 3/2 2/1 1 1/2 2 2/3 3 3
Ohio 3 3 3 3/2 2/1 1 1 1 1/2 2/3 3 3
Oklahoma 3 3 3 3/2 2/1 1 1 1 1/2 2 2/3 3
Oregon East of 122 longitude 3 3 3 3/2 2 2 2/1 1/2 2 2/3 3 3
Oregon West of 122 longitude 3 3/2 2 2 2 2/1 1 1 1/2 2 2 2/3
Pennsylvania North of 41 latitude 3 3 3 3/2 2 2/1 1 1/2 2 2/3 3 3
Pennsylvania South of 41 latitude 3 3 3 3/2 2 2/1 1 1 1/2 2 2/3 3
Rhode Island 3 3 3 3/2 2/1 1 1 1 1/2 2 2/3 3
South Carolina 2 2 2 2/1 1 1 1 1 1 1/2 2 2
South Dakota 3 3 3 3/2 2 2/1 1 1/2 2 2/3 3 3
Tennessee 3 3 3/2 2 2/1 1 1 1 1/2 2 2/3 3
Texas North of 31 latitude 3 3 3/2 2 2/1 1 1 1 1/2 2 2/3 3
Texas South of 31 latitude 2 2 2 2/1 1 1 1 1 1 1/2 2 2
Utah 3 3 3 3/2 2 2/1 1 1 1/2 2/3 3 3
Vermont 3 3 3 3/2 2 2/1 1 1/2 2 2/3 3 3
Virginia 3 3 3/2 2 2/1 1 1 1 1/2 2 2/3 3
Washington East of 122 longitude 3 3 3/2 2 2 2/1 1 1 1/2 2/3 3 3
Washington West of 122 longitude 3 3/2 2 2 2 2/1 1 1 1/2 2 2 2/3
West Virginia 3 3 3 3/2 2 2/1 1 1/2 2 2/3 3 3
Wisconsin 3 3 3 3/2 2 2/1 1 1/2 2 2/3 3 3
Wyoming 3 3 3 3 3/2 2 2/1 1/2 2 2/3 3 3