Tuning an E85 & Methanol fuel blend

[NateCrisman]

Tomorrow night Im going to hit the local dragstrip again, island Dragway with the following plan:
[*]work up to .052 nitrous jet (currently running .037 and have a .042 as well)
[*]start transitioning to Methanol fuel. Planning to mix in with e85 starting with 12.5% and mix in more and more Methanol each run in 1/8 gallon increments until I run out of delivery capacity (or blow something up) [/list]

The car has a 1gallon fuel cell and currently eats about 1/2 gallon of E85 per run on 950cc injectors at 80%DC and 40psi base pressure. On E85 I shoot for a "gasoline AF" of about 12.0:1 and I realize that I'm going to need to target a much richer A/F as the methanol percentage gets higher (down in the 9's at 100%?)

Simple to drain the fuel cell between runs so it should be relatively easy to mix fuel in 1 gallon increments and keep track of the ratio every pass.

Any tips, suggestions, comments, or advise? Should I run a hotter plug or tighter gap?

P.S. Here is a little chart to clarify the Alcohol vs. Lambda vs. Gas numbers

Alcohol Lambda Gas

6.4 1 14.7
6.2 0.96875 14.240625
6 0.9375 13.78125
5.8 0.90625 13.321875
5.6 0.875 12.8625
5.5 0.859375 12.6328125
5.4 0.84375 12.403125
5.2 0.8125 11.94375
5 0.78125 11.484375
4.8 0.75 11.025
4.6 0.71875 10.565625
4.5 0.703125 10.3359375
4.4 0.6875 10.10625
4.2 0.65625 9.646875
4 0.625 9.1875
3.8 0.59375 8.728125
3.6 0.5625 8.26875
3.5 0.546875 8.0390625
3.4 0.53125 7.809375
3.2 0.5 7.35

 

[NateCrisman]

Here's what I have figured out from lots of google searching:

Best power Lambda range for each fuel:
Gasoline: .83 to .86 (AFR gasoline scale: 12.2 to 12.5)
E85:....... .76 to .82 (AFR on gas scale: 11.2 to 12.2)
Methanol: .50 to .62 (AFR on gas scale: 7.4 to 9.2)

Seems that methanol likes to run pretty stupid rich, while E85 will run well just a little bit richer than gasoline. So Im guessing that my ideal target AFR reading from the innovate wideband will be different at each ratio of E85/methanol. On a side note, Iv read about how most of the LSU wideband sensors aren't even in the ballpark in the .5 to .6 lambda range so the "tuning" on methanol is likely not even within the range of the sensor.


of E85/Meth mixture ratio:
on a 75/25 mix I should target about 11.5 AFR (gas scale wideband)
on a 50/50 mix: ~10.8 AFR
on a 25/75 mix: ~10.0 AFR
100% meth:.... ~8 to 9 AFR


Am I being stupid here?:rtfm: