"Rev hang" on my new 370Z
 

Hey guys,

Not sure if the term rev hang is completely appropriate, however, it best describes what the car is doing. I have a 11 base with sport option and when throttling hard, in between up-shifts the revs seem to stay exactly where they were before I pressed the clutch in. I'm very careful about when I apply throttle after letting the clutch out, so it's not bad driving technique :tup:. Has anyone else experienced this issue with their Z? I know a lot of SI owners have noticed this in their cars.


This is not downshifts, as I am well aware of the rev match feature on my transmission!

Thanks guys

-Joe

Syncro Rev works for up-shifts also. :)

Yep, she goes both ways. ;)

Awesome!:happydance:

I have the sport package, but I rarely use the SRM. When I do use it, I never notice rev-matching on upshifts? I'm not sure I understand how rev-matching on upshifts would hold RPM stable ...

Consider: There are three linked factors -- gear, RPMS, and Speed. When rev-matching on the down-shift I think the system assumes you want the same speed and matches the revs according to the gear you select.

But, if it does the same thing upshifting, that would imply reducing the revs not holding them constant. If it is holding the revs constant on upshift, it must be making some assumption that you want to increase speed. Frankly, I doubt it would do that --

It may be something that isn't properly called "rev-matching" is going on when you upshift. The system may be preventing the RPMs from falling too much during the upshift (though I've never noticed this -- likely because I am applying throttle :))

It's just the dbw programming.

Good call. Not SRM at all, but rather the "rev-hang" they program in for various purposes like emissions reduction

while we're on the subject....

I have a touring Auto (no sport)...when manually down shifting, the revs spike quite a bit. Is this normal/ok

i feel like this will wear the engine quicker....

I'm think in the owners manual it even says the SRM works on UpShifts as well. Maybe its the RPM's not dropping is what your seeing.

According to the manual, if you disengage the clutch and shift, the rev-match function should lower RPMs -- there may be a slight delay. But, if you disengage the clutch and remain in gear the revs will hold at the RPM appropriate for your speed and currently engaged gear. Perhaps that is what you are experiencing.

Do they spike up to wear they should be for the new gear, or above it?

If it is just to the level appropriate for the gear, that is supposed to happen.

I don't think it is really intentional, it is just an effect of the way they run their control systems.

if you pull it out of gear and into neutral it will still hold rpm for a few seconds incase you decide to shift back into that gear. it doesn't know your upshifting or down shifting so until you move the lever to the next gate it will stay where it was

yea i guess it spikes to where the rpm's should be for a new gear.... I still think the reving will prematurely wear the engine...no?

Not appreciably, and it will save your trans.

A fraction of a second of unloaded revving isn't really a problem for the engine, but that jump to the next gear can be hell on a transmission.

what do you mean by the "jump to the next gear can be hell on the transmission"

When they're spinning different speeds and mashed together, there are all sorts of shocks sent through the system.

Either way, the transmission coding or some other type of programming, my brand new Z is not messed up so that makes me happy.

I noticed sometimes when I take my g37 out of gear, the rpms spike by 150 or so. Is this some kinda of programming?