Overrun/low load drivability

[rcntype]

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.

Idle-AFR-lean-towards-14.7-from-14.4.kal

ORon2gear.kdl

[Spunkster]

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

[rcntype]

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?

[Spunkster]

Yes that is the nature of that setting.

[rcntype]

Thank you again.