using e85 to lean out afr's?

[jesse_fc3]

i was just wondering about this the other day let me know what u guys think and only guys who know the ins and outs of e85 no e85 newbs like me, please.

right now im runnin about 20lbs on a 14b on 93. me afrs are about 10.1-10.3 at wot. i was wondering since it takes more e85 to get the same afrs as gas, if i were to mix in some e85 starting at just maybe 3parts 93 to 1 part e85 and going up from there if that would slowly lean my afrs out to where they should be? might be a dumb question but from what ive seen from the other threads on e85 and other thing ive heard it seems plausible.

i realize there is more horse to be made using dlink and straight e85 but im probably going to test this theory for the sake of science i just want to know if it will destroy something. because i wont do it if its extremly risky im also planning on turning boost down to about 16lbs while testing this out which as u know 16lbs on a 14b is pretty weak and i wouldn't think could do to much damage.

let me know what u guys think, thanks

 

[the_mork]

This would be foolish at best IMO.

Because of the drastic differences in fueling characteristics of e85 and gasoline and the reduced energy content of the alcohol as compared to gas you are literally just guessing at what is a good A/F ratio to run, let alone what A/F ratio you'll come out with.

Keep in mind that e85 likes to run at 12.0-12.8:1 (gasoline scale) at WOT whereas on a 4g63t gasoline should run 11.0-11.5:1, also even getting the fueling right e85 isn't a great fuel to run in your car because you need to be able to control timing for any real benefit. I've run e85 on a stock timing map, the car was incredibly predictable with absolutely no knock ever but it was a dog compared to the same map on gasoline.

So what would be the outcome of using e85 to lean out your fueling? Inconsistent and potentially dangerous fueling with loss in both performance and fuel economy.

E85 is a beautiful fuel, but it can and should only be used with a robust tuning system.

 

[jesse_fc3]

gotcha thanks

 

[turboglenn]

since e85 and regular gas both contain regular gas, mixing them is not an issue. i9t's mixing them accurately and consistantly that becomes the problem.

I have a friend with a mostly stock 2g (14b, 5 knob SAFC, EVO injectors,3''exh, K&N FIPK)

Now aside from using the SAFC to lean the car down he had thesame idea as you and started mixing in a few gallons of e85 with every fillup ( to try and gain better timing was the ultimate goal)

Well, his has worked out great, with the SAFC at "0" in the upper RPM's he got the AFR's slightly leaned down to the high 10's and low 11's withe85 mixing, but the issue that arose was the fuel trims not being able to compensate during normal driving.. even with adjusting the sFC to correct them the issues then became a consistant mix of the fuels, and to this day he still mixes in 3 gallons per fill up (he runs that baby right to "E") and reports that he is still happy with it and it's still running better than pure gasoline leaned down on the AFC

but anyway, yes it can be done, but without some sort of fuel control you'll get CEL's when you get too much e85 in the mix, but resetting the ECU and adding some more pump gas will help solve that (temporarily anyway)

My advice is don't mess with it unless you have a way to log what's going on and have a good wideband to keep track of AFR's