Car Bucking When Letting Off Throttle

[black18]

hey all, my si has 25k miles on it and for the last 5 or so, sometimes (30-40%) of the time i let off the throttle in 2/3/4 the car bucks a bit like I just popped the clutch. sometimes it doesnt happen, sometimes in 2nd at 2k rpm the thing rocks back and forth from me letting off. is this a RMM thing, normal, or something else?

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[Jonmd89]

Are you tuned with rev hang disabled? If so try enable cruise control and see it that smoothes it out because with rev hang enabled letting all the way off the gas jerks my car as well

 

[amirza786]

hey all, my si has 25k miles on it and for the last 5 or so, sometimes (30-40%) of the time i let off the throttle in 2/3/4 the car bucks a bit like I just popped the clutch. sometimes it doesnt happen, sometimes in 2nd at 2k rpm the thing rocks back and forth from me letting off. is this a RMM thing, normal, or something else?

Are you tuned? Do you have Rev hang disabled? When I disabled Rev hang I had this issue where it would jolt when I took my foot of the gas due to rapid RPM drop, after re-enabling it, everything was normal

 

[amirza786]

Are you tuned with rev hang disabled? If so try enable cruise control and see it that smoothes it out because with rev hang enabled letting all the way off the gas jerks my car as well

Ha ha it looks like you beat me by 2 seconds

 

[black18]

Are you tuned with rev hang disabled? If so try enable cruise control and see it that smoothes it out because with rev hang enabled letting all the way off the gas jerks my car as well

yeah, TSP with rev hang disabled. thinking it might be rev hang enabled.. gonna have to play with it after work

 

[Jonmd89]

yeah, TSP with rev hang disabled. thinking it might be rev hang enabled.. gonna have to play with it after work

I just drive with cruise control on because this disables rev hang and then when I feel like getting sport I disable cruise control and it enables rev hang delete and I can shift faster but it has jerky ness when I let completely off the throttle

 

[black18]

well, looks like that's the solution. thanks guys! I personally don't mind the rev hang.

 

[RRsedan]

I just drive with cruise control on because this disables rev hang and then when I feel like getting sport I disable cruise control and it enables rev hang delete and I can shift faster but it has jerky ness when I let completely off the throttle

Wait, I'm confused. Isn't "disabling rev hang" and "rev hang delete" the same thing??

 

[amirza786]

Wait, I'm confused. Isn't "disabling rev hang" and "rev hang delete" the same thing??

Yes, essentially

 

[ricoxg]

I just drive with cruise control on because this disables rev hang and then when I feel like getting sport I disable cruise control and it enables rev hang delete and I can shift faster but it has jerky ness when I let completely off the throttle

Did you mean that you drive with cruise control on because it enables rev hang? And when you turn it off it disables rev hang.

 

[ne0guri]

Definitely the rev hang delete. I need to re enable rev hang because I mostly drive locally and the bucking gets annoying. I’ve gotten good adjusting my driving habits to avoid it but I think I’m gonna turn it back on because I never really noticed it before getting the KTuner anyways.

 

[randomisjustfine]

Try that under 2k rpm. See if it still rocks. With Vit’s stage 1 it’s rocking when I let off the gas pedal, but as soon as you drop below 2k rpm it stops doing it. It might be helpful.

 

[Jonmd89]

Ok to clarify with cruise control on it disables quick rev drop the option in ktuner and makes the setting like it is in stock, with cruise control off it enables the option in ktuner to let revs drop faster

 

[Cheesus_Si]

is disabling revhang bad for the transmission and/or clutch? I have mine disabled but having it on didn't really bother me.

 

[fenix-silver]

is disabling revhang bad for the transmission and/or clutch? I have mine disabled but having it on didn't really bother me.

No

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