Hi guys, I just wanted to share my experience with the 4.0 gears on my car with the Auto tranny. I own a 2005 Z that came with 3.3 FD and a VLsd(both on sale if anyone is interested) I then purchased a 3.5fd(also on sale ring and pinion) pumpkin with a VLSd in it to satisfy my hunger for faster performance which i must say was an improvement over the 3.3FD in everyway. I kept that going for a year or so before I decided that I wanted to either go FI or just upgrade the gears again, I researched and got a few opinions here and I noticed that FI was a bit to much money for me right now and in the long run it would be harder to sell the car if it came about. I got a really good deal from someone here for both ring and pinion and I went ahead and bought it. I waited like 2 months because something came about and I had to put the modding on hold for a bit till situation got solved. after I went ahead and left the car at the mechanic but in the process I forgot to buy new bearings, seals etc.. I had to go for the dealer since I need my car to get around. It is $160 bucks to get all that stuff from the dealer if anyone wants to know. I waited a few days because the seals were not in stock and had to be ordered by Nissan in which it took them 3 days to recieve ARGHHH!!! Anyways, I got my car today and as soon as you get on the gas you instantly notice the difference with teh response of the car. Shifts in the D mode for the auto are still very crisp and quick. I then procedeed to opt for the sporty mode and my own manual shifts and man!!!! Wow, everything you guys read in the forums is true, (sorry for the long thread) I have the Uprev flash with the Transgo kit on my car and it feels really quick from 1-3rd, revs barely drop and it justs keeps pulling. I went also on the highway to see the difference on cruising and before with the 3.5fd revs were at 3400rpm with the new gears it just shy of 3600rpm. I was afraid of it being too revvy for the highway when cruising but it really isnt, it just feels more responsive and ready to pull at any speed. I highly recommend it for anyone who is wanting a bit more speed on your auto Z, but I must say that the 3.5FD isnt a bad idea either which you can buy for a very good price anywere if you just want something a bit quicker. All in all if any of you Auto Z owners want to ask me anything feel free to do so i would love to help. Thank you for reading !!!

 

Thanks for the write-up. Would like to see some numbers here: https://my350z.com/forum/drag/233840...ons-stock.html

 

Will do, as soon as i get her to Moroso down here in FL, I will post my times.

 

nice. What speed were you going when you were at 3600rpm?

 

I was easily able to find a 3.3->3.5 swap. any 6mt that is boosted will be glad to trade you, and it is definitely a noticeable improvement in response.

 

I was doing about 70-75 something like that. If anyone is interested I do have a 3.5 ring and pinion for sale. I also have a VLSD oem from my auto tranny for sale. I will post pics in the marketplace tomorrow, PM and we can work out a deal.

 

nice. what is your rev limiter set at?

 

Sorry for sticking my nose in, but I wouldn't sell the old gears so fast.
First, you might be slower at the track. 3.50 to 4.00 is a big move. Your car will need to be shifted one extra time. Also, your launches might be stronger than your car could handle. If you won't improve you times, i would think you might get tired of driving at 3,600 rpm at only 70-75 mph. Consider also wear on engine & loss in gas mileage. Now you can curse me out, if I ruined your high sorry.

 

Thanks for your opinion man, I dont mind it this is why i posted what I did. Am not sure about not being faster but I have though about the launches and the wear that it will have on the car and tranny. I usually dont drive like a maniac and am sure that It will prolong the wear of the car but for now is what i wanted and the car seems to deal with it just fine, the only mishab that happend was my driveshaft U joints failling but that was from b4 the swap, the car is an 05 and a replacement for the shaft is not so bad. I know it is a big move from 3.5 to 4.0 but I just wanted a different feeling than that of the conventional mods, I was going to opt for a Turbo but that didnt go so well, this will be my last mod and if i do get tired of it ill just swap it with anyone here for a 3.5 or a 3.7 g37 pumpkin.

 

a G37 pumpkin is straight swap for our cars? just like the auto pumpkin to manual pumpkin??

 

Well, I believe is the g35-37 sedans. I could be wrong but there is a thread with some good info read it.

 

interesting. would like to get a feel for your improvement.
very interested in the numbers from moroso.

can you post a parts list or a link to get the job done?
def interested in a transgo setup too.

 

Sure man, I see you live in Miami too. We can meet up sometime and i'll take you for a ride so you can see the difference. Parts, you will need a 3.5 FD preferably a pumpkin from a manual for the diff, then get the 4.0FD ring and pinion and after make sure you get the seals, bearings and gaskets from here or the dealer. Then you are ready to get all the stuff installed. Transgo kit, I did it about a year 1/2 ago I can ask my mechanic to see where he got it done for me.

 

def wanna ride bro... let's get up next week. sluggish shifts are the only
issue with the at... it's bulletproof otherwise.

 

Cruise control still work?

 

I have not tried it yet but I dont think it works.

 

Sure dude, let me see how next week is looking for me, I think I might be off Friday. I just ordered another Drive shaft from a Junker to replace my U joints ( have to buy the whole piece) If i get it installed by then I'll let you know because I dont want to abuse it just yet due to the bad U joints. Ill send you a PM.

 

same thing here very nice

 

not sure on this, but i know from the 3.5 to 3.3 swap it doesnt work. i wanna say when you elongate the gears cruise wont work in 6th gear, and i wanna say when you shorten them itll still work but dont quote me

 

Get some JWT valve springs and shims and rev that beast out to 7500rpms!