Flex fuel E85

[vampiloutre]

I read many thread about E85 flexfuel, and i don't understand why there is so many different table value on [ECM] 12678 -Flex fuel Spark.
My guess is GM know his stuff about flexfuel dnas their table are better ? or they have so many factor to consider and they tweak their table to get something ?

But E85 spark addition must be universal depending of % alcool.

[77c10]

I run e85 on another vehicle and other than having the right tune you'll want to add some lubrication to your fuel. I use this
https://www.summitracing.com/parts/P...9-31?rrec=true
E85 doesn't have lubricants that regular gas does and that can cause issues over time.

[BigTuner]

The table is large as it gives you more control over your timing when running E85, with E85 you don't want to just add say 5 degrees of timing across the whole load/rev range. E85 actually burns faster than gasoline and it actually requires less timing advance, therefore in areas of load where your timing was not knock limited on gasoline you normally pull timing but in areas where timing was limited due to knock on gasoline that is where you can usually add timing as E85 is far more knock resistant.

[vampiloutre]

The table is large as it gives you more control over your timing when running E85, with E85 you don't want to just add say 5 degrees of timing across the whole load/rev range. E85 actually burns faster than gasoline and it actually requires less timing advance, therefore in areas of load where your timing was not knock limited on gasoline you normally pull timing but in areas where timing was limited due to knock on gasoline that is where you can usually add timing as E85 is far more knock resistant.

ok it make more sense now.
Gasoline : A LS3 into a Camaro can run same advance as a LS3 into a Corvette or not ? (i know it won't be optimized to a specific car but f-body has generally less "good" tune than corvette)
if yes a GM LS3 flexfuel table can be good for every LS3 (not optimized but safe)

[BigTuner]

A good start for flex fuel tables for an LS would be a stock tune for a Caprice PPV.

[vampiloutre]

@BigTuner : thanks for tour reply (some dumb question with my english not fabulous)

[BigTuner]

@BigTuner : thanks for tour reply (some dumb question with my english not fabulous)

No problem