FINAL DRIVE UPGRADE KIT

[nissanjuke]

has anybody fitted one of these and how are they  

[Payco]

What is it buddy ?

[nub]

A shorter FD I Guess for better alleration and torque in gear, as the Nismo. Almost like turning 3rd gear into 2nd gear depending how short. Especially 3rd and 4th would pull much harder. I think up to 400bhp NA would be fine with heat in tyres a Mich PS4s or pilot cups especially flat power/torque curves. with AD08s 1st would be entirely usable foot to the floor I reckon. Mine on mich PS4s can do 0-60 1st into second without breaking traction unless tyres are cold. That’s with 360-370bhp and no passengers and in the dry. But ECUtek adjustable TC can sort it these days. On my old supercharged FN2 a longer FD only cost £90. I wonder if they’re straight bolt on and you could maybe get one from a breaker and swap when doing the clutch but who knows. 

[jollyranchers]

awaiting feedback from the first person to get this fitted 

[jollyranchers]

https://www.z1motorsports.com/oils-and-lubricants/z1-motorsports/z1-final-drive-differential-upgrade-kit-370z-g37-p-8928.html

 

https://www.torqen.uk/nissan/370z/powertrain/final-drives/1472-370z-nissan-408-final-drive-gears-350z-mt-38100-0c760.html

Edited November 30, 2018 by jollyranchers

[jollyranchers]

 

 

In german but worth a watch , tempted !

Edited November 30, 2018 by jollyranchers

[nissanjuke]

I have looked into this for my car and costs are about £2-3000  for everything including labour parts and ecutek, my  mechanic has advised me only do this if you have a track car as you would not really rate it pound for pound and has said to myself just get your car properly tuned and enjoy it  

[G1en]

From what i have read into this (and considered doing it myself) when i upgraded to the kaaz diff is in normal final drive (stock) 6th gear is only for motorway driving and saving fuel, it is not needed/used on track as 5th gear can cover the max speed your gonna do. 

(In my HR 7500 rpm in 6th equates to around 210mph)

so what a shorter final drive does is makes the whole gearing shorter, so redline in 2nd gear would be 50mph rather than 60mph and so on. This will improve your acceleration (as long as you have traction) but means more gear changes. It also makes full use of your 6 speed box but means cruising down the motorway might be at 4k revs rather than 3k (depending which final drive you change to)

My issue was and still is:

1- The cost involved (as above, around 2k unless done which other associated work)

2- The general day to day driving is compromised . 

3- It may work great at one track but not at another (ie, where you could go flat out 3rd suddenly now means you have to change to 4th for a second then back down.)

 

Apologies if you know this and you probably do but just stating what I considered. I think to sum it up, like you mentioned, if your after a drag/full track/nurburgring machine its def worth considering. For anything else probably not. 

[nissanman312]

 

[jollyranchers]

10 hours ago, nissanman312 said:

some great info there thanks , I was looking at buyign a 2nd hand diff from a breakers and fitting that with all the parts however did not realise you also need to ECUTEK the car at the same time due to issues after 6000rpm 

Will get the car mapped first then look at this again , does anyone know the cost of new bearings , shims etc ? I know z1 motorsports do a kit however would have to factor in shipping costs, any traders in the uk offer a similar kit ?

[ZMANALEX]

I use these kits in the shop on a regular basis and I charge them out at £300.00.

 

Your existing OEM shims should be reusable so do not get them mixed up, however, if you find that the tolerances are out then just measure up and get the correct sized shims from Nissan.

[350Butcher]

I installed a 3.9FD in my HR 350z at the same time as installing my lsd and its a great mod!

 

I do a good amount of track days a year and wanted the advantages for track work but also use the car on road and for large trips for hols so was a little bit concerned about the negative effects it may have on motorway cruising etc but I think the 3.9FD is the perfect choice for the type of use I do with my car. (As do Nissan as they installed the 3.9 to the Nismo 370z models)  

 

On track it pulls through the gears noticeably and usefully quicker and allows you to keep the engine in the higher revs and in the power more of the time........I felt when on track the car was regularly bogging down in gear and waiting for the engine to pull through on every track from Cadwell to Nurburgring!

 

For road use I don't feel there are any down sides at all to having this installed over standard FD, motorway cruising is at slightly higher rpm but even driving to the south of France and doing whole tank of fuel with cruise set at 90mph never bothered me at all so it's in no way as full on as "like being in 5th instead of 6th"

 

Installation wise, I installed mine myself and it really isn't a difficult job for anyone comfortable with taking a spanner to your car and definitely not £000's of pounds worth to get done by third party! 3 bearings/ 3 seals a new crush sleeve and your chosen FD is all you need to get the job done. The hardest part is tightening the pinion nut onto the crush sleeve as its got to be tightened till the pinion requires 5nm to rotate (from memory.....check the FSM) and this requires a special and expensive gauge to test as you continue to tighten. (I ran down to a local transmission guy with £20 and he was happy to help with just this part of the job and with me borrowing his gauge.......top man!). I reused the same shims either side of diff and on pinion and when it was all assembled, backlash and pinion/crown wheel mesh checked it was perfect! Maybe I was lucky..........maybe the tolerances that Nissan manufactures its FD's to is plenty good enough.

 

Obviously I can only give my view on the 3.9FD but I would say its perfect for fast road/track car and 4.08 would be superb for a track bias car but bit tiring on motorway runs if you do do the odd x000mile road trip. If you're installing an aftermarket lsd I think its a no brainer to add a new FD to your shopping list

[nissanman312]

56 minutes ago, 350Butcher said:

I installed a 3.9FD in my HR 350z at the same time as installing my lsd and its a great mod!

 

I do a good amount of track days a year and wanted the advantages for track work but also use the car on road and for large trips for hols so was a little bit concerned about the negative effects it may have on motorway cruising etc but I think the 3.9FD is the perfect choice for the type of use I do with my car. (As do Nissan as they installed the 3.9 to the Nismo 370z models)  

 

On track it pulls through the gears noticeably and usefully quicker and allows you to keep the engine in the higher revs and in the power more of the time........I felt when on track the car was regularly bogging down in gear and waiting for the engine to pull through on every track from Cadwell to Nurburgring!

 

For road use I don't feel there are any down sides at all to having this installed over standard FD, motorway cruising is at slightly higher rpm but even driving to the south of France and doing whole tank of fuel with cruise set at 90mph never bothered me at all so it's in no way as full on as "like being in 5th instead of 6th"

 

Installation wise, I installed mine myself and it really isn't a difficult job for anyone comfortable with taking a spanner to your car and definitely not £000's of pounds worth to get done by third party! 3 bearings/ 3 seals a new crush sleeve and your chosen FD is all you need to get the job done. The hardest part is tightening the pinion nut onto the crush sleeve as its got to be tightened till the pinion requires 5nm to rotate (from memory.....check the FSM) and this requires a special and expensive gauge to test as you continue to tighten. (I ran down to a local transmission guy with £20 and he was happy to help with just this part of the job and with me borrowing his gauge.......top man!). I reused the same shims either side of diff and on pinion and when it was all assembled, backlash and pinion/crown wheel mesh checked it was perfect! Maybe I was lucky..........maybe the tolerances that Nissan manufactures its FD's to is plenty good enough.

 

Obviously I can only give my view on the 3.9FD but I would say its perfect for fast road/track car and 4.08 would be superb for a track bias car but bit tiring on motorway runs if you do do the odd x000mile road trip. If you're installing an aftermarket lsd I think its a no brainer to add a new FD to your shopping list

Interesting view on it 

Even with the supercharger the gears feel so long 

And when climbing mountains on European trips I find the z very frustrating in and out of the hairpins! You just get Into the power and you got another corner 

I've always been put off by the thought of high rpm cruising but seems ok from what you are saying 

[andy james]

11 hours ago, nissanman312 said:

Interesting view on it 

Even with the supercharger the gears feel so long 

And when climbing mountains on European trips I find the z very frustrating in and out of the hairpins! You just get Into the power and you got another corner 

I've always been put off by the thought of high rpm cruising but seems ok from what you are saying 

Very interesting read. I'm in the process of building a Quaife diff to replace my Kazz 1.5 as looking to soften the driving experience a little. Totally agree that the Z is very long legged even when you add a lot of power. Might have a chat with Alex and try this.

[350Butcher]

11 hours ago, nissanman312 said:

Interesting view on it 

Even with the supercharger the gears feel so long 

And when climbing mountains on European trips I find the z very frustrating in and out of the hairpins! You just get Into the power and you got another corner 

I've always been put off by the thought of high rpm cruising but seems ok from what you are saying 

 

Agreed.........sometimes you want to snatch 1st to take hairpins as 2nd isn't quite there but I think the 3.9 makes 2nd so much more usable in tight stuff rather than screaming in 1st or bogging in 3rd.

As we now know you're only 15mins down the road you con have a run out in mine and see what you think before going for it yourself

 

12 minutes ago, andy james said:

Very interesting read. I'm in the process of building a Quaife diff to replace my Kazz 1.5 as looking to soften the driving experience a little. Totally agree that the Z is very long legged even when you add a lot of power. Might have a chat with Alex and try this.

 

Think you'll be happy with the results........it gives way more than it takes from the cars performance and the driving enjoyment/experience

[nissanman312]

1 hour ago, 350Butcher said:

 

Agreed.........sometimes you want to snatch 1st to take hairpins as 2nd isn't quite there but I think the 3.9 makes 2nd so much more usable in tight stuff rather than screaming in 1st or bogging in 3rd.

As we now know you're only 15mins down the road you con have a run out in mine and see what you think before going for it yourself

 

 

Think you'll be happy with the results........it gives way more than it takes from the cars performance and the driving enjoyment/experience

Yeah I'm really interested in this shame my diffs already built up but it sounds like this could make the z a bit less frustrating in the tight stuff