Quote:
Originally Posted by CraigM
Does the 5 Star Tube do anything to change how PE works with cruise, or should I not use cruise when in less-than-flat travel? Thanks for your insights and time taken to educate us.
|
The "no PE while using cruise control" situation is in the basic firmware of the Ford ECM. You can't change it, but you can make the fueling perfect by other means. (Unfortunately, the guys at 5 Star don't know how to do it.) So no, the 5 Star tune doesn't effect the fact that there's no PE while using cruise control. And yes, the answer is you shouldn't use cruise control unless it's nice flat ground cruising.
The 5 Star tune removes the 60 second PE delay, they change it to 2 seconds. They also lower the PE/pedal position trigger slightly (from 90% to 80%), which is supposed to make PE come on sooner but actually doesn't do much. Lastly, they richen the PE Lambda even further than Ford does, which is already ridiculously rich because they delay it so much. (OEM calibrations are known for dumping a ton of fuel in PE because by the time they enable it, the cats are about to melt and the extra fuel cools them down.)
When tuned properly, what you want is a gradual and smooth transition from stoich (14.10:1 air/fuel ratio or 1.0 Lambda) to richer mixtures as load increases. In addition to that, you can also gain mileage by going leaner than stoich, like 1.03 to 1.05 Lambda, during low load cruise and idle conditions. Those things can be done in the Ford ECM using HPTuners, it's not done that way in the stock calibrations or in the 5 Star tunes.
Thor Forums
