4.08 Frontier gear swap
 

Ok.... nobody can confirm the 4.08 gears from a frontier fit....so i ordered both the frontier gears and my original gears from nissan... so now i will be able to know for sure if they fit. Once they come ill mic them out let you know for sure. Lots of speculation. Hopefully it turns out good!!:driving:

Are the frontier gears cheaper? Is this why you are doing this? Im thinking of dong a final gear change too but I will have to get a diff too as I have the touring model.

touring model doesnt matter, it only matters if you have auto or stick. I want to stick with factory gears as nobody has any problems with them...plus i get them at lot less!!

Do you work for nissan? So what is going to be the benefit of the new gears?

oh ok I do have the auto which is why I have to change the diff too I guess. Well if they work fine and youget them at a good price let me know and Ill want one too.

changing the final gears will give you better acceleration.

What about if I am going turbo do you think it might be over the top to add such an item.

well think of it this way, the 2004 2005 STi had 4.6 gears and they're turbo. They also have awd so they will hook up a lot better. I would think 4.08 would be fine but if you're going turbo the stock 3.7 or a little higher 3.9 is what I would go with. Especially if you're doing 500+whp. On the other hand the 370z has a very linear power curve so 4.08 might be just fine ! What would also help put that power down with the higher gearing is a better LSD ! haha

Now what are the gear ratios in the transmission between the STi and the 370? You can't compare rear end ratios between cars w/ out taking into account the other side of the equation.


JB when deciding to do gear changes, its not a matter of "yes this will make it faster" its a matter of "yes this will make it faster in a certain situation" You really have to decide what you are building the car for. If you are a drag racer taller gears will usually be good. There are occasions where too tall of a gear will cause an extra shift in the 1/4 mile which isn't good if it happens right before the finish. The other thing to remember is w/ the power potential of a twin turbo, you are going to be traction limited so advantage of the gears may go up in tire smoke if you aren't running a drag radial or slick.

If you are doing time attack or similar gearing is going to depend on what track you are running at. If you have a short track taller gears are going to be better for your acceleration, if you have a long track the taller gears can be too tall and limit top speed.

I did the 4.08 frontier swap on my 08 G 37 . Love them . Wish I did this mod first .. I posted it on my G37.com..

^^^ auto or stick?which frontier did you get them from?

Car is a stick and the nissan part # is 38100-0c760

good...thats the exact number i ordered. thanks for the info

we installed the 4.08 and track tested it...here are a few notables
1.)the car accelerates faster, however, if you are still NA, it didn't make much of a difference the added drive was lost due to the added shifts or running out of gear.
2.)in situations where we were in 5th and had some drive, 6th now has a tough time overcoming the aero drag.
3.)synchro revmatch failed a few laps in... then became unreliable... we turned "s mode" off
4.)Greddy TT is almost done... I will give some updates at 450whp in 2 weeks... We will be testing on a long and short track in the same weekend.

^ NA = Naturally Aspirated. Meaning no forced induction (supercharged, turbocharged)

yep

Could you elaborate on SRM becoming unreliable? How so?

A few laps in it would not operate... so I would start heel toeing. Then it would come back on, and so on. In one instance it didn't work in an area that REALY upset the car. So we just opted to leave it off. Our traction control is wired off permanently. I'm certain UpRev or COBB could solve it quickly. We are also running an OS clutch and flywheel, may be contributing due to quicker revs?

ok...so the gears came in and after measuring eveything it looks like its a go only issue that i see is the new ring gear is a little thicker but it shouldn't be a proble.now the only thing i am waiting on is i ordered in a new pinion nut, crush sleeve and both pinion bearings. when they come in ill tear down my diff and install.

Last guy I talked to on this said his syncro rev stoped working after the gear install.

^ Thats huge.

hopefully not :shakes head:...but we will see . i plan on installing the gears in a few weeks...

We need a Sticky thread that states exactly what you need for this based on what you have:

Base Manual (no LSD) ---> ?
Base Auto (no LSD) -----> ?
Sport Manual (LSD) -----> ?
Sport Auto (LSD) -------> ?

:iagree: I have been trying to firure out which parts exactly I would need to do this. I know I need a different diff and they say the 350Z will do but does that mean I lose a gear by using their diff?

when i get done with this install..ill post up everything you need with all parts numbers, but before i do i want to see a perfect install.

The diff has nothing to do with the number of gears. From what I understand if you have an auto you need the pumpkin. If you already have a diff your axles are good to go, but if you don't have a diff you may need axle stubs. I may have some of that backwards and that is what I'm trying to verify.

Jnaut, how did the cat gutting go?

cool thanks for the info. So I guess I will need the pumkin and stubs and will do the LSD too if I do this. Might just go GTM SC too but would still want the LSD then.

For all the effort to replace parts, you may as well just get a complete pumpkin from a older 350Z MT; rebuild and install the 4.08 gears. The older pumpkins just bolt into the 370. There isn't much difference between the years.

this is true. if your have a manual sport or non sport it is the same gear. the limited slip doesnt matter. on autos the carrier( where the ring gear bolts to) is different. you would need to change this to a manual car one and also the little stub axles going out of the diff or buy a 350z manual read diff.


tonight i am starting the install of the frontier gears.i will be posting up any issues that i run into.

kind of a pain, but all done and installed, but there coming off soon the long tubes are going to be here in mid june...

Good luck! Keep us posted.

so you ruined a good stock product when you were going to get the lung tubes. Now if you need to go back to stick ones you will have to buy new ones. I could see if you werent going to get others but you are. Not mad at ya tho, just not the way I would have done it. So how does it sound and perform?

sounds like a good idea. Thanks.

I said the same thing to him... He bought a second set of stock ones, and gutted those.

Man he must have money to burn.

ok, so tranceformer and i work on the gears last night. pulled the diff out and started installing the gears.Almost done, just need to press the new pinion bearing onto the new pinion and set the backlash.Everything should be done tonight.

its not about the money, just havent seen anybody else try, so ill be the first. yes its a pain, as for the sound/performance prolly just like test pipes. no i would not do it again, just buy a set of 200$ test pipes off ebay. now back to topic the gears...:tup:

I supervised and took pics, Jason did the rest. :)

one other thing, I have a SPL diff bushing set from when I had my 350Z, never got around to installing it or even selling it. Kuah@SPL assured me that the front bushings would fit and the rear would stick out a little bit since the 350Z rear subframe is a little bit thicker. Last night, we checked it while we had the diff out. Everything looks good, I think I may end up keeping the diff bushings for my Z. :tup: