I don't really think the EPA has anything to do with the off-on throttle transition abruptness. The lean surging, and some of the other ills... yes, absolutely. But that is not your complaint.
The reason there is a sudden jerk when you first roll on the throttle (from fully off) is that the Fuel Injection cuts all fuel during "over-run" condition. That is the technical name for the condition that occurs when you chop the throttle off fully while decelerating and engine braking. The reason for this may be emissions related, but I'm almost certain** that the EPA never tests vehicles for emissions output during over-run.
In any case, a Power Commander does very little to alleviate that condition. You can fatten up the initial injection, which makes the on-throttle surge less objectionable, but you really can't add any fuel on over-run.
** I could be wrong, which would certainly explain why every manufacturer does the same thing
You are wrong Fred.
One of the Power Commander's biggest gains is off/on throttle transitions. Cures the 'lean surge' that is all too frequently present when rolling on throttle from a closed position.
No,
you are wrong, Skooter.
"Lean surge" has nothing at all to do with rolling on the throttle from closed. Lean surge is the "hunting" feeling that you get when cruising along at a steady throttle. I have a PCIII, my FJR does exhibit lean surge, and the PCIII did fix that. But none of that has anything to do with off to on throttle transitions
The only way that a Power Commander can help in off to on throttle transitions is by adding fuel in the 2% throttle column. By making that mixture overly rich you can soften the transition somewhat when you crack the throttle. But you cannot eliminate it because the ECU will still cut the fuel off on over-run. By the way, this is not unique to the FJR by any means. This applies to most fuel injected motorcycles.
What would be needed to eliminate this issue is something like the Ivan's Fuel Cut Eliminator. Those usually fool the ECU into thinking that the throttle is never fully closed, so it continues to send some fuel during overrun and you don't get the jerkiness when you re-open the throttle. You would also lose some of the engine braking that you get with a closed throttle now.
What I was saying I may be wrong about was whether the EPA tests emissions on trailing throttle. Not whether any of that happens.
