"Rev hang" on my new 370Z

SWO(N) NAVY · 06-29-2011, 11:54 AM

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

. 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

Cmike2780 · 06-29-2011, 12:02 PM

Syncro Rev works for up-shifts also.

WhiskeyHotel · 06-29-2011, 12:05 PM

Yep, she goes both ways.

SWO(N) NAVY · 06-29-2011, 01:44 PM

Awesome!

Zaggeron · 06-29-2011, 02:27 PM

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

)

Red__Zed · 06-29-2011, 02:31 PM

It's just the dbw programming.

Zaggeron · 06-29-2011, 04:15 PM

Quote:

Originally Posted by Red__Zed

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

Econ · 06-29-2011, 04:43 PM

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....

red6spd · 06-29-2011, 05:06 PM

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.

Zaggeron · 06-29-2011, 09:07 PM

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.

Red__Zed · 06-29-2011, 09:13 PM

Quote:

Originally Posted by Econ

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....

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.

Quote:

Originally Posted by Zaggeron

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

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

1slow370 · 06-30-2011, 08:24 AM

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

Econ · 06-30-2011, 08:50 AM

Quote:

Originally Posted by Red__Zed

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.

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?

Red__Zed · 06-30-2011, 08:54 AM

Quote:

Originally Posted by Econ

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.

Econ · 06-30-2011, 09:17 AM

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

06-29-2011, 11:54 AM	#1 (permalink)
SWO(N) NAVY Base Member Join Date: Jun 2011 Location: SC Posts: 15 Drives: 2011 370Z BCS Red MT Rep Power: 14	"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 . 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

06-29-2011, 12:02 PM	#2 (permalink)
Cmike2780 A True Z Fanatic Join Date: Jun 2010 Location: Long Island Posts: 5,059 Drives: slowwww Rep Power: 29	Syncro Rev works for up-shifts also. __________________ [09][MB][6-Spd MT][Touring][Stillen Gen III][K&N][Borla CBE][Evo-R] [ArchitTEK Photography]

06-29-2011, 02:27 PM	#5 (permalink)
Zaggeron A True Z Fanatic Join Date: Jan 2010 Location: Austin, TX Posts: 1,951 Drives: '10 370ZR '13 BRZ Rep Power: 18	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 ) __________________ 2010 Platinum Graphite 370z Roadster:Touring/Sport 2013 Subaru BRZ Limited

06-29-2011, 04:43 PM	#8 (permalink)
Econ A True Z Fanatic Join Date: Jan 2011 Location: New York City Posts: 2,546 Drives: Fiat? Rep Power: 19	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.... __________________ 2014 Triumph Thruxton 900 2013 Fiat 500 Abarth 2009 Nissan 370z

06-29-2011, 05:06 PM	#9 (permalink)
red6spd A True Z Fanatic Join Date: Apr 2010 Location: Long Island NY Posts: 3,277 Drives: 2010 Z Coupe M6 SPT Rep Power: 21	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. __________________ 2010 Base+Sport 6spd: Stillen G3, FI Non-Resonated CBE, FI Non-Resonated Test Pipes, UpRev Tuned, Custom 24R Oil Cooler, JDM Rear Fog-OEM Harness. ???Whp ???WTQ (Will find out come spring time)

06-29-2011, 12:05 PM	#3 (permalink)
WhiskeyHotel Track Member Join Date: Nov 2009 Location: Oklahoma Posts: 530 Drives: 2015 GT-R PW Premium Rep Power: 17	Yep, she goes both ways.

06-29-2011, 01:44 PM	#4 (permalink)
SWO(N) NAVY Base Member Join Date: Jun 2011 Location: SC Posts: 15 Drives: 2011 370Z BCS Red MT Rep Power: 14	Awesome!

06-29-2011, 02:31 PM	#6 (permalink)
Red__Zed A True Z Fanatic Join Date: Jul 2010 Location: window seat Posts: 28,940 Drives: Mostly on two wheels Rep Power: 120	It's just the dbw programming.

06-29-2011, 09:07 PM	#10 (permalink)
Zaggeron A True Z Fanatic Join Date: Jan 2010 Location: Austin, TX Posts: 1,951 Drives: '10 370ZR '13 BRZ Rep Power: 18	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. __________________ 2010 Platinum Graphite 370z Roadster:Touring/Sport 2013 Subaru BRZ Limited

06-30-2011, 08:24 AM	#12 (permalink)
1slow370 A True Z Fanatic Join Date: Aug 2009 Location: In the D Posts: 3,732 Drives: v8 74 260z ;) Rep Power: 7251	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 __________________ ANSWER PRICE LIST Answers - - - - - - - - - - - - - - - - $0.75 Answers (requiring thought) - - - - $1.25 Answers (correct) - - - - - - - - - - $12.50

06-30-2011, 09:17 AM	#15 (permalink)
Econ A True Z Fanatic Join Date: Jan 2011 Location: New York City Posts: 2,546 Drives: Fiat? Rep Power: 19	what do you mean by the "jump to the next gear can be hell on the transmission" __________________ 2014 Triumph Thruxton 900 2013 Fiat 500 Abarth 2009 Nissan 370z

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