I'm running open ecu tuned by mike for my fmic 840s and vf39 and needless to say I burn a lot of gas. the rear lip is filthy with carbon from the smoke which leads me to think I'm running a little too rich. My car uses sooo much more fuel even on the highway after the turbo swap, is this normal and is there anyway to get a map for highway driving that I could store on my laptop and flash the map that I already have when I want it for performance.
I was actualy just thinking the same thing. What if i get cobb AP or Utec will i be able to switch from an econo map to performance map?
my educated guess.no they won't burn more gas if tuned properly but they have the potential to when getting on it.
I'd suggest getting a wideband to know where you're at. You shouldn't use any more fuel with larger injectors and what not. They just make it trickier to tune.
The funny part is, that a GOOD tune will get you good milage.There is so much more to a econo map than AFR. I know on the way home when I was just cruising, I was well into the 31-32 mpg. And that is with a 18g, 630cc injectors and a modded 4eat tranny. Most econo maps really don't get better mileage. What you want to do is maximize your low end torque so the motor doesn't have to work as hard to keep the car moving. Since the ecu (as of now) will not let you run any leaner than 14.7:1, the only thing you can do is mess with timing. Another thing to watch is fuel trims at each load point. It is alot of work getting the under the curve stuff dialed in. Russ
I believe you can target afrs leaner than stoich for closed loop operation on the 16-bit ecus with Enginuity. Also, larger injectors will not trash your fuel economy for things like highway cruising. 14.7 afr is just that -- air/fuel ratio -- and regardless of the size of injector, two cars running the same afr with the same airflow will inject the same amount of fuel. I would suspect that most fuel economy downward trends after a major modification are the direct result of newfound power and the throttle being consequently stuck at WOT. :laugh:
