2003 Cobra - FBGIO - E85 Tune Settings

[2003RedfireVert]

2003 Cobra, 2.8 KB, Fore Return, 80lbs, SCT BA3000, tuning with Binary Editor and a Mongoose Cable. Dynacom wideband through a DataQ box...yada yada. The car runs great on the 93 tune I've done. MAF curve is very close (as close as I can get it doing WOT pulls, datalogging, tweaking, flashing the ECU, etc)...No concerns at all. It drives well under all conditions.

I've done some research but I want to confirm all that's needed to change in the tune in order for the car to start and run on E85. My base O/L fuel table is already set up properly (lambda values obviously). I want to be able to at least drive the car down there with E85 in the tank. I don't want to take up dyno time disconnecting a line, turning the pumps on to drain it, etc....

From what I have gathered, all I need to do is change the Air Fuel Ratio in the Fuel Scalar table to be the Stoich for E85 (which is 9.8). I believe everything else will happen downstream to that since it's all the fuel tables are in Lambda. Is that correct? Am I missing something? Seems way too easy. I wasn't sure if any injector data needed to be tweaked. I'll leave the timing tables alone as those will obviously be tweaked on the dyno. Thanks as always!

 

[01yellercobra]

That's how it's done in SCT. The injector data doesn't change because of the fuel. Dead time is dead time.

FWIW, I only bumped the timing at part throttle a couple degrees. I advanced it like I did the WOT numbers and the engine ran on the warm side. I did some research and found a lot of guys kept the part throttle stuff around the same as pump gas. So I backed it off and the car ran cooler and still has snappy throttle response.

 

[2003RedfireVert]

Cool. I’ll tackle this in a few days. Tune is 11/17 as long as our baby boy stays in the oven.