Has anyone else noticed that the RPMs between shifts actually seem to go up alittle or stay the same when off throttle?

It seems that the Revs do not drop immediately even after letting off the gas in the Fit between shifts like all the other manuals I have owned. I wonder if this rev hang is an issue or just programmed that way.

 

your foot is still on the gas when you hit the clutch.

 

I also have a 07 350Z which does not have this issue, so I doubt that my foot is on there. The RPM's will eventually start to decrease, however the delay is what I'm talking about.

 

blame it on drive by wire and decreased emissions.

 

haha yeah... you're not imagining things... its in both the GE and GDs... i call it the rev float... lol

if i remember correctly theres a choke point in the clutch line... i remember i posted something about it a while back n did a search and someone said they replaced the slave master cylinder with an Si slave and the float disappeared...

but this is from memory... use the search button or google it...

*edit* i did a quick google because i remember bmw had a similar thing in their clutch line.. CDV, clutch delay valve

 

yup, timing is different on the Fit. But really it doesnt matter, just ease into the clutch like normal and it should still catch cleanly and smoothly

 

dela, from what i've read, it's a function of the ECUs software leaving the throttle open for a little while longer to reduce the amount of unburned particulates expelled after the gas pedal is released.

 

interesting... sounds very possible..

but my info is from memory... so i could be wrong *shrug*

my question would be... why would petrol need to be efficiently burned while decelerating? for the hypermilers? to slow the deceleration rate?

not trying to prove u wrong.. just something that popped into my head

 

 

i suppose there is still a decent amount of fuel in the cylinders even after you step off the gas pedal and this function burns up that fuel so it comes out cleaner when it is expelled from the exhaust.

i do remember reading about the clutch delay valve that you wrote about since i'm the owner of a an older BMW and i used to frequent BF and other e30 forums. if memory serves me right, they have a similar purpose for emissions reasons and supposedly smoother shifting. the CDV came before the ECU induced "rev hang" of current cars.

now i'm not sure that it helps me shift smoother since i'm used to the revs dropping immediately on my past manual driving experiences.

 

ooh... makes sense...

yeah... its more of an annoyance for me...

 

Yeah, what "neil patrick harris" is descibing exactly what I am experiencing. Like the DBW is not closing the throttle when I tell it. Well it must be a Honda emission thing since Z's and my old E36 M3 use dbw as well but don't/didn't have any delay.

Now that you mention it, I have also noticed a considerable response difference in the throttle when accelerating as well. I.E. - If you try to blip the throttle quickly to heal-toe there is also a delay.

If anyone has tried heal-toeing on the fit it is a PAIN! Has anyone been able to do it effectively? I hope someone comes out with a electronic solution!

 

when i blip the throttle while engine compressioning it will back fire like 5 times hahaha it sounds sick! but if i let go of the throttle then hit it again and stay on it, it will only back fire once. but with the intake i made and the custom exhaust i have i dont have that rev hang as bad as before and my car has become way way way more responsive no more lag! hahahah

 

while cruising some of the mountains w/ buddies, i have had no trouble heal-toeing... i really only notice the float during daily driving

picture just for fun

 

Definitely designed that way thanks to the clutch delay valve. i've noticed that it happens when lugging it around and shifting lower in the rpm range, As long as i'm at least semi-winding it out, no rpm hanging. it's still pretty annoying though and would love a real solution on how to remove/replace it.

 

it is because of the gearing very close ratio gears.

 

I haven't really noticed it, but I don't wait too long between shifts. In any event, it is not nearly as bad as my 3.8 liter Mustang was.

 

this is normal on this car. burning off the last of the fuel.

 

you notice it now but give it a year.. it'll become normal to you. I learned how to switch between DBW and normal throttle, took a while but it's pretty cool once you get it down

 

Hear, Hear! Emissions do drive this, a rapidly closed throttle does not scavenge well and has a steep spike in certain emissions components. The rev hang also makes shifting a little smoother for less-skilled drivers, probably keeps the engine mounts healthier longer as well. The behavior of Honda's drive-by-wire is another reason I picked my Fit with my first AT for a daily driver.

I don't know if any of the throttle controllers affect this. Anyone out there with one to confirm/deny?