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Throttle Blip Stumble, TTS

Started by Don D, November 28, 2020, 05:30:55 PM

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Don D

I just finished several Vtune sessions on a 2020 RG. Went very well. Just one small hitch and I am sure it is an easy fix. Blip the throttle, on the floor, and it stumbles, not bad but noticeable. Is this a candidate for changing the Accel Enrichment Table? What are typical changes?

Ohio HD

If it throttles ok when the motor is cold, but stumbles when warmed up, I'd say the VE tables need attention. 

rigidthumper

Easy way to tell is to change the AE table by 15%, flash it in, and evaluate.  I find properly calibrated VE tables require a little less AE, but that's not a hard and fast rule...
Ignorance is bliss, and accuracy expensive. How much of either can you afford?

Don D

Makes sense. Does the idle speed play into this? It is set at 860 I think when warmed up. How about AFR/Lambda at idle and surrounding cells? I had it rather skinny .988 in closed loop. Bike runs phenomenal except for this minor hiccup.

rbabos

Quote from: HD Street Performance on November 29, 2020, 10:16:05 AM
Makes sense. Does the idle speed play into this? It is set at 860 I think when warmed up. How about AFR/Lambda at idle and surrounding cells? I had it rather skinny .988 in closed loop. Bike runs phenomenal except for this minor hiccup.
It can if the idle ve for that rpm isn't populated correctly. I always tried to collect data in the 750 range by dragging the engine rpm down with long slow launches with brake and clutch a few times.
Ron

harpwrench

The ECM/vtune could also be taking down the VE in that area, if it's digging a hole you might need to raise egr or even take it out of closed loop below 1500, and give it some fuel.

rigidthumper

Remember when you blip the throttle the map load goes way up.   You could be 1500 RPM @ 60 KPa when blipping, and transient areas are overlooked in VTune. 
Ignorance is bliss, and accuracy expensive. How much of either can you afford?

Ohio HD

True story.

Below:
record 119
RPM = 961
MAP - 37.6

Quick throttle blip:
record 122
RPM = 1,920
MAP - 60.9


That's a quick jump to 60.9 kPa



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