370z 7AT interesting (to me) note...

kannibul · 08-13-2009, 06:58 PM

If accellerating quickly, and letting off quickly (say around 45mph), the engine will drop down to 1K, sometimes below - as if in neutral.

If you get on it again (say, up to 60MPH but with a mild accelleration), and watch the RPM guage, it'll go up (as expected) then drop down a bit...then if you let off, the engine will stay locked to the tranny and you can engine brake.

I assume this is the torque converter "stalling" or is this something else?

It does this both with it in "D", and in the auto-stick mode, though it's MUCH more noticable with the auto-stick mode - for example, you go through 1/2/3 and then shift it to 4th, and let off. While it's unlocked like that, it also seems to mess with the synchro-rev a bit, where it'll rev up, but it just kind of revs down instead of engine braking.

I've not yet noted what RPM it "locks" or for what duration the engine has to be running before it does it (since you can go over 5K in each gear prior, and it doesn't "lock")...

I know most guys (if not all) that track their Z have a standard tranny, but, if one was to track a Z with an auto, I imagine this could be an issue as engine braking is pretty important.

Anyhow, something odd I noticed - then again, can someone confirm their 7AT also does this?

awesomez · 08-13-2009, 08:21 PM

My understanding is that it has 100% lock from 2nd gear and up in manual mode. That's exactly how it feels to me. It jerks like manual when I shift, depending on the RPMs. When you are playing in auto mode, there could be a lot of different things. I think that the 1k rpm you're seeing is the 7th gear which might be out of ordinary to you. Auto mode does attempt to learn drivers driving style and if you are unpredictable, your transmission is unpredictable. Needless to say my transmission was unpredictable the first 500 miles until I got used to it.

Trips · 08-13-2009, 08:41 PM

Quote:

Originally Posted by awesomez

My understanding is that it has 100% lock from 2nd gear and up in manual mode. That's exactly how it feels to me. It jerks like manual when I shift, depending on the RPMs. When you are playing in auto mode, there could be a lot of different things. I think that the 1k rpm you're seeing is the 7th gear which might be out of ordinary to you. Auto mode does attempt to learn drivers driving style and if you are unpredictable, your transmission is unpredictable. Needless to say my transmission was unpredictable the first 500 miles until I got used to it.

I drive it in manual mode as often as possible and do find the shifting a little buggy but not a big deal most cars with the same setup will probably have the same issues.

1GR8Z34 · 08-14-2009, 03:17 AM

Didn't happen to me yet but I'll double check again. anyways I do notice the syncro-rev matching everytime I down shift it that's got me interested!!!

joe370z · 08-17-2009, 01:21 AM

I noticed this too the other day, basically it feels like the car hits neutral in gear (if that makes sense) but it only does it when you come of the throttle. I got a feeling this is a fuel saving thing that in normal auto mode when you come off the throttle it is not engaging the gear and hence not wasting fuel with engine braking. Although in manual mode this didnt happen if felt like 100% lock all the time and it was definitely engine braking off throttle.

wstar · 08-17-2009, 02:06 AM

I've been playing with it for months. What triggers the "loose" feeling is when you let off the throttle during (or very close to) an upshift event. Usually what you're trying to accomplish when it happens is to accelerate through gear X, then switch to X+1 and immediately coast (or engine brake) in that gear. The usual snappy shift is laggy and loose when you do this. The solution is not to drop off the gas when you're shifting. Hold the gas through the shift until the next gear engages solidly, and *then* back off the gas. Basically it can't predict what you're going to do next, and it has certain expectations if everything's to work smoothly. Just learn the expectations.

need4speed · 08-17-2009, 12:21 PM

Quote:

Originally Posted by joe370z

I noticed this too the other day, basically it feels like the car hits neutral in gear (if that makes sense) but it only does it when you come of the throttle. I got a feeling this is a fuel saving thing that in normal auto mode when you come off the throttle it is not engaging the gear and hence not wasting fuel with engine braking. Although in manual mode this didnt happen if felt like 100% lock all the time and it was definitely engine braking off throttle.

The 2 times I test drove this car they were both pretty extensive drives done mostly in manual mode. This car was very easy to engine brake n bring back up to power.
But owning 2 nissan auto/ manuals already you get the general feel for the 7spd pretty fast.
This 7spd engine brakes a lot better thn both my former G35 n current 3.5 altima.
I really hope they come with tranny upgrades on this auto?
Does anyone kno if this tranny is double-clutch. Cuz it performs like it?

awesomez · 08-17-2009, 12:51 PM

The old auto transmissions didn't do a full lock. That's why the engine braking didn't quite work. The new one does. You basically get the benefit of full lock of auto-manuals without the headache of not being able to parallel park. Still though double clutch should have been an option on the 370Z.

Lug · 08-17-2009, 12:51 PM

Quote:

Originally Posted by need4speed

The 2 times I test drove this car they were both pretty extensive drives done mostly in manual mode. This car was very easy to engine brake n bring back up to power.
But owning 2 nissan auto/ manuals already you get the general feel for the 7spd pretty fast.
This 7spd engine brakes a lot better thn both my former G35 n current 3.5 altima.
I really hope they come with tranny upgrades on this auto?
Does anyone kno if this tranny is double-clutch. Cuz it performs like it?

Not a double clutch, just an excellent rendition of a traditional Auto. The same (I think) auto is in the FX45 with 390 hp so it's gonna be good for quite a bit more ponies than the previous AT.

Modshack · 08-17-2009, 12:55 PM

Quote:

Originally Posted by Lug

Not a double clutch, just an excellent rendition of a traditional Auto. The same (I think) auto is in the FX45 with 390 hp so it's gonna be good for quite a bit more ponies than the previous AT.

Yup...Low stall, fast hook-up traditional torque converter. Having driven Audi DSG's, I like this better and long term reliability should be better... A double clutch trans is gonna be a fortune to repair when they start breaking..

wstar · 08-17-2009, 07:46 PM

Still, the fast shift times of the double-clutch designs would be nice. I hope someday soon the state of the art advances to where we can all have a more reliable, cheap, light version of the double-clutch paddle-shifted manuals.

08-13-2009, 06:58 PM	#1 (permalink)
kannibul A True Z Fanatic Join Date: Jun 2009 Location: Jenks, OK Posts: 2,281 Drives: 370z Touring/Sport Rep Power: 266	370z 7AT interesting (to me) note / question If accellerating quickly, and letting off quickly (say around 45mph), the engine will drop down to 1K, sometimes below - as if in neutral. If you get on it again (say, up to 60MPH but with a mild accelleration), and watch the RPM guage, it'll go up (as expected) then drop down a bit...then if you let off, the engine will stay locked to the tranny and you can engine brake. I assume this is the torque converter "stalling" or is this something else? It does this both with it in "D", and in the auto-stick mode, though it's MUCH more noticable with the auto-stick mode - for example, you go through 1/2/3 and then shift it to 4th, and let off. While it's unlocked like that, it also seems to mess with the synchro-rev a bit, where it'll rev up, but it just kind of revs down instead of engine braking. I've not yet noted what RPM it "locks" or for what duration the engine has to be running before it does it (since you can go over 5K in each gear prior, and it doesn't "lock")... I know most guys (if not all) that track their Z have a standard tranny, but, if one was to track a Z with an auto, I imagine this could be an issue as engine braking is pretty important. Anyhow, something odd I noticed - then again, can someone confirm their 7AT also does this? Last edited by kannibul; 08-13-2009 at 07:06 PM.

08-17-2009, 02:06 AM	#6 (permalink)
wstar A True Z Fanatic Join Date: Mar 2009 Location: Houston, TX Posts: 4,024 Drives: too slow Rep Power: 3594	I've been playing with it for months. What triggers the "loose" feeling is when you let off the throttle during (or very close to) an upshift event. Usually what you're trying to accomplish when it happens is to accelerate through gear X, then switch to X+1 and immediately coast (or engine brake) in that gear. The usual snappy shift is laggy and loose when you do this. The solution is not to drop off the gas when you're shifting. Hold the gas through the shift until the next gear engages solidly, and then back off the gas. Basically it can't predict what you're going to do next, and it has certain expectations if everything's to work smoothly. Just learn the expectations. __________________ 7AT Track Car! Journal thread / Car setup details

08-17-2009, 07:46 PM	#11 (permalink)
wstar A True Z Fanatic Join Date: Mar 2009 Location: Houston, TX Posts: 4,024 Drives: too slow Rep Power: 3594	Still, the fast shift times of the double-clutch designs would be nice. I hope someday soon the state of the art advances to where we can all have a more reliable, cheap, light version of the double-clutch paddle-shifted manuals. __________________ 7AT Track Car! Journal thread / Car setup details

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08-13-2009, 08:21 PM	#2 (permalink)
awesomez Base Member Join Date: May 2009 Location: VA Posts: 199 Drives: 09 370Z Touring 7AT Rep Power: 15	My understanding is that it has 100% lock from 2nd gear and up in manual mode. That's exactly how it feels to me. It jerks like manual when I shift, depending on the RPMs. When you are playing in auto mode, there could be a lot of different things. I think that the 1k rpm you're seeing is the 7th gear which might be out of ordinary to you. Auto mode does attempt to learn drivers driving style and if you are unpredictable, your transmission is unpredictable. Needless to say my transmission was unpredictable the first 500 miles until I got used to it.

08-14-2009, 03:17 AM	#4 (permalink)
1GR8Z34 Enthusiast Member Join Date: Aug 2009 Location: M-Town Posts: 365 Drives: 2010 Mitsubishi OB-X Rep Power: 15	Didn't happen to me yet but I'll double check again. anyways I do notice the syncro-rev matching everytime I down shift it that's got me interested!!!

08-17-2009, 01:21 AM	#5 (permalink)
joe370z Base Member Join Date: Jul 2009 Location: Australia Posts: 38 Drives: 09 370Z Rep Power: 15	I noticed this too the other day, basically it feels like the car hits neutral in gear (if that makes sense) but it only does it when you come of the throttle. I got a feeling this is a fuel saving thing that in normal auto mode when you come off the throttle it is not engaging the gear and hence not wasting fuel with engine braking. Although in manual mode this didnt happen if felt like 100% lock all the time and it was definitely engine braking off throttle.

08-17-2009, 12:51 PM	#8 (permalink)
awesomez Base Member Join Date: May 2009 Location: VA Posts: 199 Drives: 09 370Z Touring 7AT Rep Power: 15	The old auto transmissions didn't do a full lock. That's why the engine braking didn't quite work. The new one does. You basically get the benefit of full lock of auto-manuals without the headache of not being able to parallel park. Still though double clutch should have been an option on the 370Z.