E85 tunning?

fASTCAV29 · Post by **fASTCAV29** » Sat Jul 11, 2009 5:56 am

Any body mess with tunning for E85?

Post by **robertisaar** » Sun Jul 12, 2009 9:12 am

its pretty simple, just instead of running the 14.7:1 stoich ratio of regular gasoline, its richer. i think its around 9.7:1. spark also needs to be retarded, somewhere in the area of 5 degrees everywhere

Rogue_Ant · Post by **Rogue_Ant** » Mon Jul 13, 2009 9:24 am

Check the table here:

E85 AFR Table

Also, you will want to advance timing, not retard it. I would start with a 3degree increase.

-Rogue

Post by **robertisaar** » Mon Jul 13, 2009 4:18 pm

actually advancing does make sense, e85 is rated for like 105/110 octane or something close to it. it would take a lot of advance before any detonation sets in...

thats what i get for googling whether e85 needs more or less advance...

loastbeachbum · Post by **loastbeachbum** » Fri Jul 31, 2009 6:51 am

what about running E85 on a turbo vehicle? I know when running forced induction having advanced timing is bad and generally timing is retarded a few degrees. What would be your advice for a forced induction vehicle that wants to run E-85

Six_Shooter · Post by **Six_Shooter** » Fri Jul 31, 2009 7:21 am

loastbeachbum wrote:what about running E85 on a turbo vehicle? I know when running forced induction having advanced timing is bad and generally timing is retarded a few degrees. What would be your advice for a forced induction vehicle that wants to run E-85

The engine will still want more advance with E85 than with regular gasoline. The fact that there is a turbo on the engine does not change how the fuel reacts. It only changes how volitile the over all mixture can be, since a higher compressed air charge is warmer than a lower compressed air charge, it is this heat that is the problem. With how E85 works, you would still run more advance with E85. You will just need to tune to what the engine likes.

Sammy · Post by **Sammy** » Sat Aug 01, 2009 3:02 am

i haven't actually tested all my theories on E85 but i am looking at it as an option for a drag car and from everything i read it looks like its similar to methanol in how you set the car up, more timing, more fuel and compression.

main reason i want to use it is because its available at the pump and its as close as you can get to methanol without having alot of methanols hassles.

kilogram · Post by **kilogram** » Sun Aug 02, 2009 3:16 pm

you'll also want to almost double the cranking enrichment for cold starts. warmup enrich is a bit less linear than gasoline in my experience too.. my 3SGTE wants lots of enrichment until there is a little heat in the manifold (or it wets the manifold walls sufficiently) then it rapidly needs less and less.

when i switched, i added about 23% fuel across the board and the mixture was pretty much perfect.

for a turbo engine too, you can run low boost areas of the map a bit leaner (13.5:1 AFR equivalent) to help spool the turbo and save fuel while cruising (it doesn't dump fuel every time you go near boost while on the highway). i tuned my cruise portions to ~17:1, but i'm running open loop full time and the actual AFR varies a bit with whatever the fuel concentration is at the time i fill up.

programmign my WB02 for narrowband emulation with the crossover point around 17:1 and switching to closed loop will take care of this, but the car is so much fun to drive right now i don't have the ambition to fiddle with it!

Sammy · Post by **Sammy** » Mon Aug 03, 2009 3:59 am

kilogram wrote:when i switched, i added about 23% fuel across the board and the mixture was pretty much perfect.

yeah 25% is the figures i've heard!!