Originally Posted by marcua56
Yes im n/a and really? what kind of tips do you have? how much differece do you think it will make?
First, I'm going to assume you are framiliar with some ecu-tuning "common sense" kinda things..
Compared to a gas-tune....
- E85 makes slightly more power in 80F weather than pump gas makes in 50F weather with essentially the same tune.
- A few times now, I've seen the knock count rise up to 3 in the midrange where its usually quiet pump gas, but then in the higher rpms where pump gas usually gives me trouble, the E85 runs are completely knock free.
- Its not like race gas where timing can be liberally increased. It has to be that E85 has much more stable burn characteristics.
- The main advantage i see besides adding timing over pump is the cooling effect..
I am running a pretty substantial amount more timing on E85 then I was on pump gas..I have also found that running it richer allows more timing for me, so I am tuned to about 11.3-11.4 now where as I was hitting knock on the same ign map running ~11.7.. Part of the reason it makes good power is because it's highly oxygenated. It means you can use a lot more fuel. Which means more power. Remember gasoline's lambda is 14.7 afr, E85 is ~9.8. That's 1.5 times the fuel. 1.5 more fuel will make more energy even though unit per unit ethanol has lower energy content than regular gasoline. We want several things out of fuel - fast burn and detonation resistance being the most important ones. High oxygenation and cooling are other very good qualities. All those make power. E85 exceeds gasoline in all those. The more I mess with E85, the more I get the feeling that its possible to hit MBT with no knock. I have fiddled around with economy tuning on E85, and I am still learning, but amazingly I have gotten results like 16: or 17:1 with little load (just cruising) and run 40* of timing at cruise!)
The thing about E85 that SUCKS is that the winter and summer mixes are NOT the same - I have heard this is because it can actually be E70 (15% less) sometimes. Of course all of my tuning work is done on "unnaturally" aspirated machines. If you really want to get a monster-bang out of any small engine E85 is a huge winner.