darn honda rev hang

[Nayov]

I haven't owned a manual trans car since the 80s, and though I was aware of rev hang, it's really bad (2015 Fit).
Shifting 1-2 is clumsy affair and as an added bonus, it grinds a bit going into second, so I either double-clutch it (sometimes) or time it so as the revs decrease, it goes into second nicely. What controls this? The IACV? Has anybody come up with any tips, techniques or tricks to mitigate its effects? I know, "engineers know best, leave it alone, that's how its designed" but it greatly distracts from the driving experience.

 

[redhat]

I experienced this on my 2009 Accord. I ended up tuning it out with KTuner. That was about the only thing I could do to make it more drivable.

 

[Rand]

its for emissions and yes sucks.. both my MT foresters had it.

 

[MRC01]

its for emissions and yes sucks.. both my MT foresters had it.

Yep. Apparently, if the throttle closes quickly it emits a little blast of bad stuff out the tailpipe. So the ECU doesn't let the throttle slam closed; it slows down the rate at which the throttle closes. Some cars (Subaru, Honda) have this worse than others (Mazda) but they all have it.
From what I read, fixing it requires a re-flash and may be illegal depending on where you live.

 

[BMWTurboDzl]

I haven't owned a manual trans car since the 80s, and though I was aware of rev hang, it's really bad (2015 Fit).
Shifting 1-2 is clumsy affair and as an added bonus, it grinds a bit going into second, so I either double-clutch it (sometimes) or time it so as the revs decrease, it goes into second nicely. What controls this? The IACV? Has anybody come up with any tips, techniques or tricks to mitigate its effects? I know, "engineers know best, leave it alone, that's how its designed" but it greatly distracts from the driving experience.

I remember reading about this with the early 2000 CIVIC RS. Try short shifting? 1st gear is really just to get the car moving and most of the acceleration is in 2nd and up.

 

[Tman220]

Yup, emissions, and it really really sucks trying to drive relatively modern cars smoothly without slipping the clutch into each gear since the revs hang forever.

I find that deliberately letting the throttle close completely a split second before clutching helps immensely with the rpm hangs. (as opposed to letting off the gas and hitting the clutch simultaneously)

This may not work with the fit since the above tactic is used on a cable throttle 04 civic with a different engine, ecm, logic, etc

 

[Deleted member 89374]

@Nayov I take it that this "feature" grinds your gears?

 

[meep]

Our 18 civic is similar.

shift to 2nd early. The rev hang isn’t an issue, the 2nd synchro will thank you many, many times, and the engine should have the torque to do it; you may just need to dig deeper into the throttle at the bottom of 2nd, just like the ecu would in an auto or CVT anyway.

 

[Nayov]

I forgot to add that if I slam-shift it into 2nd it won't grind most times and it is relatively smooth. I discovered this by accident when I had to merge into a line of traffic with no choice but to move quickly. I don't know if cramming it into gear that way is perhaps causing more damage than that little unpleasant grind, though.

 

[KrisZ]

Here is a thread about a pedal commander. Form the sounds of it, people report a great improvement and it has several sensitivity modes to choose from, so you can match it to your liking or driving style.

Pedal Commander thread