Since I've had my Fast Intentions exhaust installed, I've spent a lot more time in manual mode with the 7AT. With that being said, I've been able to make some observations with regard to shifting that I thought I'd share. I do not have a tune (yet) on my car.

I have found only one shift going up through the gears and one shift going down through the gears that I've found satisfactory and to my liking.

It's well documented here about the 7AT sluggishness, hesitation, etc so I won't spend too much time getting into that or TCM firmware updates. When you're into the skinny pedal, I've found that the 3-4 shift is lightning fast-- approaching the speeds of a DCT-- you can really hear how quickly that shift is executed with the exhaust. All other gear shifts are pretty slow and leave a lot to be desired.

When downshifting, I've only found the 3-2 shift to be quick and to my liking. All of the others just feel slow and lethargic. I'm sure Infiniti and Jatco tuned this transmission to have mass appeal and so there wouldn't be complaints of the car shifting too hard. I would love to do the GTM valve body upgrade but don't necessarily want to throw down for a new unit while mine is being worked on at GTM. The downtime thing is a deal breaker for me.

I've resigned myself to just accepting the 7AT the way it is and if I want something more aggressive, I'm just going to have to pick up a GT-R down the road.

 

Have you installed a ground wire kit? Improvements with the tranny are pretty good for connecting wires... Thanks for the good review.

Doug

 

Yes thanks for the review. I have the same question as above. I was kinda hoping the shift lag would be solved (well enough at least) with the Gk. let us know Snails

 

I don't have a 7AT, but I DID have the 5AT with similar disappointments.

I did an extensive back-to-back trial with the grounding kit on and off. Multiple times in my case.

Absolutely no change whatsoever.

Biggest change was the Jatco shift kit (5at). Not sure if they offer a 7AT package.

I have always wished the trans ECU could be easily reprogrammed. I was just discussing the sagging 6AT on my Mustang with my shop owner this week. Just as the trans is ready to shift, it feels like the power drops 10% until it reengages. Jimmy says this is what the OEM'S do. This is the kind of stuff which is computer controlled.

I'd love to understand more. Good luck.

Jim

 

Sorry for the delayed response here. Hey Doug, I have not yet installed the grounding wire kit. I have the wire sitting on my desk...I just haven't gotten around to building it. But since I already have all the stuff, I should just make some time and see if it makes a difference. I know that grounding wires have been discussed at length here and it'll be interesting from a first person perspective. YMMV definitely applies here.

Jim, thanks for your input. I've followed your turbo build and rear gear swap quietly in the shadows. I was bummed to hear that you got rid of the car.

Where did you get the Jatco shift kit for the 5AT? I'd like to research that some more just to see what's out there for this trans. I've heard that UPRev allows the line pressure to be upped on the 7AT to make crisper and quicker shifts. I do plan on getting the UPRev tune but that will probably be the extent of what I end up doing with this transmission. I had been planning and eyeing the GTM valve body upgrade but it's my understanding that they're in bankruptcy. I also was not willing to send my valve body into a black hole and wait for it to get done. That's just not an option for a DD.

 

I had my tuner up the line pressure and it shifts very hard now.

I like it though you feel the power.

 

Malady, do you notice that the shift speed is quicker with the higher line pressure? I'm definitely going to have that done when I get tuned.

 

Matt, thanks for the thread, definitely in for updates, keep us posted.
BTW, what RPM range were you finding the best point for the quickest 3-4 upshift? I too have found that particular upshift to be very good, most of my upshifts are reasonable when really on the gas though. Around 5500 rpm seems to be a sweet spot for me.

 

that why i got a 6spd manual this time around AT sucks *** and is not rewarding to drive just my honest opinion.

 

depends when I shift.

Sometimes i will get a weird lag If I shift under 3k or so.

The more I throttle the faster it seems to engage.

 

No problem Brad. I've generally found that anything above 3,500 is pretty fast though, even if I'm only at partial throttle. I've thought to myself if every gear shifted that quick, we'd have ourselves a pretty decent trans.

That's pretty much what my tuner has said. Basically, the harder you get on it, the harder and quicker it shifts. I've heard anecdotally on here that higher line pressures contribute to less transmission wear and tear over time, which is the exact opposite of what you would think.

 

Coincidence? My Titan shared the same 5AT tranny. I first had a line pressure increase and that was great, I went with the Jaco shift kit and the chirping of tires and crispness of shifts was awesome. Then I had a torque converter with 2.5 str and raised the stall from 2600 to 3400 ( I had JWT S2 cams). That was the trinity. I think in the VQ without the availability of a shift kit raising the stall by 500 with a 2.0 str would put the tranny in a sweet spot along with line pressure.

 

I concur. ^^^ and THAT is what propelled the quickest VQ37VHR in the world. 370Z's are still trying to play catchup.



Coop