7AT 4.08 gear swap review
 

I just had the 4.08 gears installed in my 7AT 2011 Z a few days ago. Seb at Specialty Z did the install and did a great job. I had a diff sent directly to their shop so it was all ready and they just had to do a pumpkin swap when I brought my car in. That is definitely the way to do it.

So with the new gears, the engine revs much quicker and smoother. There used to be a lag and sort bogged down revving int he low RPMs until you hit the range where there's actually power. Now the car is always in or very close to that rm range so it's always ready to go. Freeway driving is much nicer now, when I want to accelerate or pass, it just happens, no more laggy revving to the 3k range. Another bonus is that the engine sounds smoother when cruising since I am in the upper 2k to 3k rpm range. I have FI resonated HFCs and CBE and there was a lot more noise when cruising before in the low RPMs. I used to put it in M to raise the RPMs sometimes for the quieter ride. Of all my mods, this is the one I feel the most after install. I had HFCs and CBE installed with a tune all at the same time and the difference in driving feel and fun was less than this.

No review would be complete without stating the negatives as well. Like everyone else has noted, cruise control no longer works (see update below, it is now working) but i rarely ever use that anyway. I'm also losing maybe 2-3 mpg in freeway driving.

A note to those with 2011 and newer models. Mine was the first one newer than 2010 that Seb installed the gears in and I had the Service Engine Soon light come on. The code was p0500 which is Speen Sensor A. Seb chekced I tout and the problem si that there is some kind of miscommunication between the sensor and the ECU. Since theya r enot getting the same reading, it si throwing the light. HOWEVER, this isn't really a problem because it doesn't affect or damage anything. Also, my speedo still works fine and gives me about the same reading as my nav for my speed. Seb can program the ecu to get rid of the light so it's no biggie since it doesn't really affect anything. If I get more info on it form him, I will update this post.

UPDATE:
My cruise control is now working. I guess whatever it was Seb did to fix my Service Engine Soon light also gave me back my cruise control. I tested it to confirm it didn't work right after I had the gears installed. I tried it again tonight for the hell of it and was surprised to find the cruise control was now working. I even turned it off and set it a second time to make sure it wasn't a fluke.

Another UPDATE
I drove from Los Angeles to San Francisco and back this past weekend. I was mostly cruising around 80 and got about 23 or 23.5 mpg for the trip.

nice :tup: I am looking to do the same in the future.

Do you need a 6MT pumpkin to do the swap? Did you find the pumpkin yourself?

Yeah, you need a MT pumpkin with vlsd if you have a sport. Yeah, Seb can get the gears but not the pumpkin. I found mine on ebay from a '08 350z.

First to second must be so fast for you when you launch! It's really fast for me lol.

The 3.692 swap into the 7AT is geared higher than the 4.08 in a manual, minus 5th gear, and you're 10% above that. It'd be cool to compare the two. Do you have any videos? I love the 3.692 in the 7AT. Much better gearing!

No videos, just had the install done Friday.

How much did he charge to do that if I may ask. PM me if you don't want to say it private. Thanks!

Subd.....

is the CEL still on , or can it be recailbrated not to come on. Inspection issues ? No?

Seb turned the light off after confirming it wasn't a real problem and programmed the ECU to not have the light come back on for that reason.

updated my review regarding cruise control for anyone sub'd and interested

just talked to Seb, going to go there tomrw and see if he can fix my cruise control problem too. Will update you all on what happens.

Cool, hope it works out for you too.

[QUOTE/]The 3.692 swap into the 7AT is geared higher than the 4.08 in a manual, minus 5th gear, and you're 10% above that. It'd be cool to compare the two. Do you have any videos? I love the 3.692 in the 7AT. Much better gearing![/QUOTE]

Do you need to find a used 3.692 gear or can you buy new? I also have the 7AT. I am more interested in the 3.692 than the 4.08 swap. Does it need the same pumpkin from a MT?

Does the 3.692 also cause cruise control to not work?

Thanks.

If you want the 3.692 gears from a manual, then you will need a manual pumpkin 350z ones work just the same as 370s). I am not sure if you can find them new. You'd have to ask Nissan. Everyone gets them used. If you're not swapping out gears then it'll probably be a straight pumpkin swap. As for cruise control, we got mine to work even with the 4.08 gears so I can't imagine it would be a problem having it work with 3.692.

So if I get a 370z MT pumpkin, it already has the 3.692 gear, I can just swamp pumpkins?