Hondata

I drive a 2001 Toyota mr2 spyder with a K24a2 swap. Using Kmanager 4.2.0 on a PRB ecu. Mods are custom 3" intake, stock header and custom 3" exhaust and rsx-s vtc limited to 40deg. Everything else is stock.

I have an issue with overrun/low load drivability, not sure if its mechanical or the tune/settings.

Going into overrun feels abrupt but whats worst is coming out of closed injector overrun to very low throttle, basically bringing it out of overrun makes the car jerk like I was just learning how to drive manual. I checked the logs and it seems that ignition is going up and down during this time which is making my rpms go up and down. In the log I tried to be very easy on the throttle just to show with such light throttle application, it is still making the car jerk.

I noticed If I have "Disable fuel overrun cutoff delay" checked, it helps slightly with the jerkiness. However log was done with that unchecked.

Thanks for any help you can dispense.

You might want to look at the acceleration smoothing retard tables: http://www.hondata.com/help/kmanager/ge ... meters.htm

Thank you for pointing me in the right direction.

I played around with "tip in gear retard multiplier" and +50 for the low gears seems to help the jerkiness. This is great for driving slow and smooth. Driving around testing it out I noticed that whenever I needed decent/quick acceleration, at +50 retard % it kills acceleration for the duration obviously because of the retarded timing.

Currently I've lowered it down to about 15% for gears 1/2/3, 5% for gears 4/5 and -50% for gear 6 and will try these settings out tomorrow but I can already tell, that jerkiness will be back but atleast its not as bad as before.

Are we stuck with choosing a middle ground of good low load drivability versus quick initial acceleration?

Yes that is the nature of that setting.

Thank you again.