E85 and timing

[steve_gee]

I am thinking of looking at a e85 setup on a 3000Gt vr4. Is timing a big factor with e85? Can I use a SAFCII with bigger injectors and keep the stock timing curve if I use the stock turbos?

[ricehunter]

Ok, from what I've heard you should be able to run e85 with bigger injectors, larger fuel pump, (some people say you need better fuel lines) and some tuning with some type of fuel management (ie SAFCII) I'm looking to do this myself on a 2g DSM so I'm interested in this too.

[cotsi95]

You need fuel lines that are ethonal compatiable. Ethonal makes rubber expand so all the o rings and other rubber pieces will ballon up. An safc should be good enough to tune with. You need a bigger fuel pump, fuel lines, fpr, bigger injectors, and i would do a new fuel filter.

[t_jolt]

Depends on how much fuel you plan to run. Cause even with e-85, an safc can only compensate for 660 injectors, reliably.

Tyrel

[1990EclipseGSX]

Cause even with e-85, an safc can only compensate for 660 injectors, reliably.

Tyrel

I don't see how this is possible. From what I understand you need to run ~30% more fuel on E85. Based on that, it seems that you could possibly put 30% larger injectors in the car and have it run fairly well on e85 with no adjustments. So, if you put some 660 injectors in, you would run 30% more fuel compared to 450's, and the car should run pretty well with no AFC adjustments.


Also, e85 has a much higher octane than pump gas, which means it will take more timing advance to fully burn the fuel. Therefore you should also be able to pull out more fuel with an AFC on e85 then you could with pump gas before you get onto an overly agressive timing map.....

Which, IMO, means you should be able to run much larger injectors than 650's reliably with e85 and an AFC.

Just my speculation though.

[Cloud]

That's pretty much right. You could theoretically just put 30% larger injectors on and not have to tune a thing. It's nice to actually pull fuel out though over a stock overly rich map and if you can get more timing you will like it. And about the rubber fuel lines... they are fine. I have some o-rings that are starting to dry out but the rest of the lines seem to be holding up pretty well and definitely nothing has failed yet. The worst that has happened is the ethanol washed all the varnish out of my tank and into my fuel filter and it started getting clogged so I changed it for like $10.

[steve_gee]

3000gt only have 330's on a v6 TT. Some do a "Hotwire" on the fuel pump to increase the voltage to get more fuel from the pump for 450's. If you wan't to get into 550's to 1000's, then you need a much larger pump. I was thinking about the "Hotwire" and see if I needed more fuel with 450's or 550's. 30% would be 430's
Rightnow I am running Stock 9b's with boost controller, Catback and HKS intake. Should be around 360hp.

Any opinion on Apexi nero vs SAFCII?

[steve_gee]

** Update ** Flexfuel
I did more research on the "E85 conversion kits" boxes. Most FI cars have a correction map for injector pulse. This lets the car compensate for running conditions like air temp, octane, more restrictive air filter, etc. It is said that the car has the ability of + or - 15%. If you add 20% to the injector pulse, then the new map is -5 to + 35 %. This would let you then run full gas at a - correction to E85 at a + correction. Mixes of 50/50 would be in the middle. :cool:


These "Kits" are $250 to $400.

Looks like to me that you could use a Apexi AFC or SAFC tuned with a 50/50 mix and be close to what you would need. Will the Apexi let the ECU still compensate the duty cycle?

Apexis $100 to $350

[1990EclipseGSX]

Will the Apexi let the ECU still compensate the duty cycle?


I would think so, the AFC only modifies the airflow the ECU sees.

[prophecymiller]

I think the first thing to start off with is a wideband...that way you know where you stand with your mixture however you decide to tune.

Also being able to adjust timing is a very good idea since you can run a different curve with e85, but I don't think it's completely necessary- you will still make power, just not as much if you wanted to stick with the afc.

[Cloud]

I don't think that a wideband is as 'necessary' as everyone makes it out to be. I would sure love to have one but I haven't really been able to justify the cost. My tuning consists of a keydiver chip and maft adjustment for small corrections. While I wont say this is the best setup, you can tune wot pretty easily based on how the car responds, and you can tune the rest of your stuff based on fuel trims in place of the wide band. It is far from ideal but I still get over 20mpg and make better power than other people I have known who did have wide bands.