Interesting. I'll try it once I"m comfortable with this initial tuning we're doing. Why so much leaner at 30lbs, if you meant 13 AFR?
e85 update
- Thread starter turbodaniel
- Start date
Interesting. I'll try it once I"m comfortable with this initial tuning we're doing. Why so much leaner at 30lbs, if you meant 13 AFR?
Rafs-T-Type
Not so Senior Member
- Joined
- Mar 8, 2009
I said to go a little fatter with 30#'s, 11.5 to 11.4. I said some people (not so much in buicks) have leaned out to 13's, however I would not recommend it.
Thanks for the clarification
You do not tune E85 as
Are you tuning your AF according to the fuel energy constant or by gas with stock ECM or XFI.
Rafs-T-Type
Not so Senior Member
- Joined
- Mar 8, 2009
Stock ECM....gas scale.
I hate taking over this thread making it technical, but can you explain power density?
TT/Ameasap
The White Blur
- Joined
- Jan 31, 2002
18psi is low 11's for me and a stock car at 18psi is low 13's in the 1/4 mile
When you are tuning E85, your VE are actually going to be lower. So if your idle VE is 40 with gas, then with E85 your VE is going to be around 28-30. 80s on E85 would be able to support the same power 42s would on gas. When using E85 the 30% rule never seems to actually work out, so you usually need to double your injector size with a FP base of 45psi. With the classic, you don't have the fuel energy constant option. So you need to adjust your TARGET FP according to gas:E85. Your perfect stoichiometric air fuel ratio for gas is 14.7 in turns equals 9.8 on E85...... Now if under, you want to shoot for a gas AF of 9.37 = 7.35 E85. This will go the same with the SD chip.... It is similar to the classic until Bob and Eric get the fuel constant working. Now this target AF is only a baseline. If the car wants the fuel, give it to it...... With E85, You can run more timing and more boost.
That is pretty lean, you still have almost 2 percent of AF to use. E85 loves high compression and boost.
BEATAV8
The Engine Whisperer
- Joined
- Feb 14, 2002
Power per engine size.
Rafs-T-Type
Not so Senior Member
- Joined
- Mar 8, 2009
Double the injector size would flow 100% more, not 50% more. Also 7.35 is about is about 11.1 on the gas scale. Under boost aiming for a 9.37 sounds pretty damn rich to me....if that's what you mean by "now if under".
9.37 is pretty lean on an E85 scale. I will disagree with you, and so will many others. You are currently running 120s to achieve the same thing that you could with 55s.
Rafs-T-Type
Not so Senior Member
- Joined
- Mar 8, 2009
You're not making sense here. You said "Now if under, you want to shoot for a gas AF of 9.37 = 7.35 E85" To me that sentence reads under boost you want to aim for a 9.37 on the gas scale which comes out to a 7.35 on the E85 scale. Is that not what you meant? I said that 9.37 seems rich which I thought was obvious that I was talking about the gas scale, as you were just talking about that number on the gas scale. Now if you are talking about running boost at 9.37 on the E85 scale, then yes it would be lean as that translates to about a 14:1 on the gas scale. And again 9.37 on the gas scale will not equal 7.35 on the E85 scale. 9.37 would be more like 6.2 on the E85 scale, which is rich as all hell. However going the other way 7.35 on the E85 scale come to about 11.1 on the gas scale which I think is a little rich, but perfectly acceptable AFR.
I also disagree with you about the injector sizing. I would say you need about 50% larger to make the same power...so 60lb injectors, for example, would become 90lb as 60 x 1.5= 90
Last edited:
Rafs-T-Type
Not so Senior Member
- Joined
- Mar 8, 2009
Boost level?
Similar threads
