Downshifting on 7at and not jolting
 

This is probably a bit of a newb question, so I apologize. I was under the impression that with the 7at's the downshift rev match would blip to keep the downshifts smooth. Can this be turned on or off? I just got my Z the other day and when I downshift the RPM's spike up a little bit and the car jolts pretty aggressively. I've been trying to smooth out this while downshifting in manual mode, but haven't had a lot of success yet. Any suggestions? I thought the DRM feature was supposed to smooth this out for me?

The higher the RPM's the more of a jolt your going to get. I don't think there is any way around that. Also, don't downshift into 1st, just let it do it if it needs to.

So how low should I let the RPM's go before I downshift?

Depends on how smooth/aggressive you want to be. Generally if it's around 3,000rpm before you downshift, it should be pretty smooth.

Your profile says you drive a 350z.... I believe SRM is only avail on a 370z

He said he just got it the other day, so I assume he just hasn't updated his profile.

Exactly. I'll update now.

Hrmm, I'm trying to downshift now at around 2000 RPM's and I still jolt pretty badly.

From what gear?

Seems to happen in the 4-3-2 range the most. The higher gears its not nearly as prevalent.

Hmm, I dunno, seems fine to me.

try it by applying light throttle (slight blip with your throttle) when the lower gear engages.

Should be no reason at all to need to do that with the 7AT to get smooth downshifts. I don't. It will already blip to revmatch anyway.

it was just a suggestion.


also SRM on MT isn't all that smooth at lower rpm with light braking. it is only smooth on moderate to aggressive braking/downshifts. so i tap the throttle to help rev match during light braking/downshift. might be the same on AT's.

You can't turn off the DRM right? It's always automatically supposed to work?

I thought the 7AT doesnt include SRM whether you bought the sports package or not.

I'd of suggested the same. Maybe only on sport package does SRM?

Hey maybe it's time for an auto vs manual thread. :stirthepot:

Right, no way to disable it. It's part of the 7AT, regardless of package. A lot of AT's actually have some form of SRM.

:icon18:

i downshift at the lowest rpm possible and its not jerky. A lot of times if you dont downshift the computer will do it for you and its very smooth

The 7AT has a strong downshift especially in the lower gears. I rather like it because that's how it's supposed to feel. This is not a luxury car for smooth shifting. If you shift a G37 7AT it feels weak as sh1t

but us MT guys have smooth shifting while you guys are hiccuping at lower speeds? is that ok?

:ugh2:

Here's an idea... keep it in D. It won't jolt. Lol. Manual is for sport shifting not smooth shifting... but I do have one question...
Are you shifting from the paddles or from the sttick? The paddles shift way smoother than the stick. Keep the rpm"s below 3000 when downshifting and use the paddles. The Z is not completely smooth when downshifting even at its smoothest point in manual mode.

Don't even down shift in manual mode... just slow down and let the car downshift for you. That is the smoothest way. If you manually down shift it will jolt.

:iagree: This is probably the OP's problem. 4th to 3rd isn't much of an issue, depending on what RPM you do the downshift at. 3rd to 2nd - well, let's just say you better not be going very fast or you'll feel it (and it probably isn't very good for the transmission either).

Yea I just got back from driving it again and its definitely most prevalent in 3rd to 2nd, but noticeable in 4th to 3rd. Is there any downside to letting the cpu downshift for me? I suppose I could just do that, but figured it'd be better to downshift myself *shrugs*

It is a transmission that wants you to have fun. This is how it was designed.

Well said

is that the same philosophy they used for the steering lock? :icon17:

:bowrofl:

Slightly different, the steering lock is for the Z to have fun while Screwing-Lock the driver.

:icon18:

hahahaha. :icon17:

If you wait too long to downshift from 4th to 3rd, the computer will downshift for you at the same time you are downshifting, then you end up in 2nd with a high rpm and jolty. This has happened to me on several occasions.

You probably shouldn't downshift as a way of engine braking if the tranny will take care of it for you. Plus the brake pads are cheaper to replace...

Downshifting for the sake of accelerating is a different story. I have found that if I keep the throttle relatively static and down shift, the throttle blip combined with my steady foot results in a really smooth shift and sets me up to plant it when the time is right. This is counter intuitive to most drivers since your instincts are to lift off the throttle since it will SRM on it's own. The throttle position varies depending on what RPMs and what gear you are in when you make the downshift. I have more of a feeling/connection with what's right by now and love how it feels to drop a gear and then seamlessly transfer to warp speed. ;)

when im driving on the highway coming up on a red light i typically paddle shift down from 7 to 2nd from about 63mph. the Z pretty much stops itself and doesnt seems like it's doing any damage, plus by the time i slow down enough the lite is green and take off agian. but brake pads are definitely cheaper, ill try and break that habit.

I find 20mph is a good time to go 3-2. I find 4-3 is good around 35-40. Any time going from 7 down to 4 7-6, 6-5, 5-4 its always smooth. Never go to first. Let car do it if it wants.

Downshifting to slow down doesn't cause any more wear on the transmission than acceleration does as long as you're in the limits of the RPM range, don't believe wanna be mechanics.