I have a 2011 G37X sedan with now 500 miles on it and I know exactly what everyone means. I am going to go see the dealer see about this flash. If I am driving 35-40MPH step on the break down to 25 then instantly step on the gas, there is a second to maybe 2 second hesitation and then a lurch forward. I understand that I came from a manual mustang but this to me is unacceptable. I love the power of the car and all the interior and the handling, but if I have to stop and go quickly on a side road or merging on a highway it is just plain dangerous. I can reproduce this pretty consistently so I will take a tech for a ride with me if necessary.

 

The lag we have is a combination of things, a conflation of mechanical parts and programming which results in the 'lag' - as another poster pointed out, much of the lag is likely the physical result of the 7AT's torque converter - we have a very timid transmission - it's slow to lock, and it seems low stall rate?

Knowing we have a 330 hp sports sedan that will get driven like at B out of H on a regular basis, it seems that infiniti engineers wanted to reduce transmission and torque converter failures like ballooning, stator clutch issues, seal problems and turbine deformation. That's one of the reasons why we are limited in the amount of RPM we can rev to while the breaks are applied, and why it is hard to abruptly launch this car. The torque converter simply takes its time to engage and disengage, and there's very little one can do about it except get a 6MT or professionally rebuilt 7AT.

And then there is the throttle tip-in programming which is on the timid side as well, but is strangely abrupt as you engage the throttle more. I think the 2007 G35 5AT had a much less physically 'timid' transmission., and super-responsive throttle programming, resulting in a more viscera experience. My G8 GT had all of these modern protections built in as well, and when people began removing some of the tranny programming protections like shift torque levels, the transmissions began breaking. Mostly seal and inner stator clutch issues resulting lots of slippage, loss of power and crappy gas mileage (and full replacement / rebuild of the transmission ) - other guys got tough aftermarket racing TCs with higher stall speeds and haven't had issues.

All of this is just my theory. I have facts to back it up.

 

I'm beginning to wonder if the newer trans software versions may be contributing to the dangerous lag people are experiencing or I'm just lucky not to have had this issue. I've got 20k on my 09 G and have only had the hesitant/clunky shift issues and have just decided to live w/ it for the most part. I doubt I'll be getting any newer software flashes until we get a more positive consensus, and definately not if I keep hearing about this dangerous lag problem still occuring after the latest reflash TSBs. Pretty scary situation if you ask me

 

Very educational post, Ozzypriest... I will say that after over 1K miles since the reflash and riivng as much as possible in DS mode of the 7AT, it's "better"....i have centered the Lag at about 1600-1700 RPMs, no matter what the cruising speed at thaty RPM level, if you hit the Gas, I experience that Lag...not 2 seconds, but a solid 1 to 1.5 second. That;s why when travelling - local roads, hit the brakes to make a turn and quick step on the gas, you get a Lag. Anyway, I'm leasrning to lvge with it and just keep protesting - maybe there's answer from Infiniti at some poi

 

so...should I get this update? lol

edit: i just called the dealer and asked about the update. advisor basically told me that it will improve the jerky downshifts, but the flat spot (lag) will still be there somewhat. it will also make the car behave a little less aggressive. basically it tames the car. meh...i think i'll skip this for now.

 

Interesting they specifically note that lag....wonder if they know of anything upcoming that might fix it as well?

 

Has anyone with a 7AT got a tune? My bet is it's not the transmission entirely but the stock tuning as well which explains why some have the lag and some don't.. the stock tune runs well in their enviroment. The trans is only half the equation, if you improve the engine's responsiveness you'll improve the overall cars performance.

The other half of the problem is probably programming which tries to keep the RPM low for fuel economy and it's in this low RPM state where lag is experienced. That's why folks that manually shift or drive it agressively don't experince the lag since their keeping the engine in a higher RPM.

We're I in this boat, I'd get a tune, and then keep it in DS and drive like I'm late most of the time...which trust me after a tune you'll be wanting to do anyway. The rest of the time I'd enjoy the fuel economy cruising.

 

I'm in your Court.....acknowledgement from the Dealer but it's Infinti that must Pay Attention. Let's keep it up. There has to be more members that have this experience with the 7AT 2010-2011, probably 2009s too. I think Red's post after yours, makes some sense as others have described: it is the Torque Converter in this 7 AT with the 3.7 engine. I'll accept a little of the jerkiness, b/c it seems that other cars with 6 speed and 7 speed auto trannys have it too, its the Gear Hunting - too many gears to choose when downshifting and coming to a stop. But the lag / hestitaion has to be FIXED !!! I'm still trying to return my car and "swap it for a 2008 M35X , but my Dealer has told me that its going to be expensive to get out of the lease. I don't like the Ms - 2011 looks like a "stretched" G to me.

Sniper27: It does shift smoother with the reflash and coasts a little better to stop - better in stop and go traffic, a little less aggressive - I would agree with that. But it "seems" to me a little better in that regard too after 1K miles. With the freakin weather here in the NY area lately, its been difficult to Drive 'er Hard in both modes D or DS.. I'm going to try to reset my ECU again next week and then drive it hard to see if there is a difference. I know you are on the fence about the reflash, I think there will be others. Good Luck with your decision.

 

I am holding off on this update for now

Perhaps Infiniti would come up with an "updated/improved" 6 speed transmission for the next gen instead of the current 7 speed trans. I hate the lag but since I drive mostly highway, I can live with it for now. It's sad that I moved away from Lexus because of its "lazy" transmission (aka "lag") and heard all the good things about the 5AT in the G35.

I am pretty determined to get a RSX-S for my fun car and let my G37 be a cruising machine. I also wonder if 370z folks experience the same problems as we do though.

 

I got my oil change today and decided to skip this reflash. Like I mentioned, the advisor told me it basically tames the car and makes it less agressive, in both upshifts and downshifts. Can't just fix the downshifts, and the lag will still be there somewhat. He said once you get the update, you can't go back. meh.

 

PS Hypertech guys. They emailed me today to inform me that they have an updated calibration...

2' of snow here, so I won't be testing it out for awhile. lol

 

LOL...the next one will be an 8-speed, at least. Look around at the other engineering leaders (M-B, Lexus).

 

LOL I know right? IMO, 6-speed is a sweet spot. 8-speed units from MB or Lexus is just marketing really. Plus, I can't imagine paddle shifting thru 8 gears. That would be a pain rather than a "feature".

I am going to try the new 6AT that Acura is putting in their 2012 TL. But then again I need to keep my eyes closed until I get inside a TL

 

Thanks to everyone here Ive started noticing the lag

After watching the tach flutter I have to think its more of a software/"confused transmission" issue than a torque converter issue. In my case I see the RPMs jump up a little (which may very well be the torque converter unlocking), then come back down (torque converter locking again?) then the bog down. If you press it hard enough to begin with it seems to downshift OK but if you dont stab at the throttle it will bog a bit before downshifting.

Oddly enough, my Frontier does something similar....it will hop up a couple hundred RPMs, come back down then downshift depending on how far you are on the fun pedal.

Maybe its just more noticeable in our cars because of the extra gears.

 

2012 GTR 6 speed is nice. :-)