R32/R34 RB26 front diff swap out

[Diomedes]

I'll explain.

I want to keep my options open regarding modifying my car, and to this end I have decided if I end up modding the R34, I'm going to pull the engine out complete and keep it together, and build another engine complete to put in and thrash/risk. Aim is to go modest, keep the new motor stockalike with around 400 whp, so I shouldnt need to do anything crazy with the rest of the drivetrain.

Preaching to the choir here, but parts for RB26's are getting harder to come by and more expensive. Trying to find a R34 RB26 is proving quite hard, and I would imagine even if i could find one it would be ridiculously expensive. I have found a RB26 that looks to be in decent condition that suits my plan, but has a 2WD sump attached. I have now found a RB26 sump off a R32 GTR, so I now have a 4WD sump to go onto the RB26. Only problem is final drive ratios. 

What are people's opinions? I have found the part No. for the R34 GTR front diff final drive gearset, 38100-00V00, but they are discontinued and are probably going to be hard to come by, but it seems in my (unqualified) opinion to be the easiest way forward?

Anyone ever used this kit? https://www.nengun.com/tomei/final-gear-set

What about the Quaife front/rear diffs for the GTRs? (I don't know enough about the kits and what they replace.)

The car is a V-spec, which means if I go the other way and change the rear diff I will have to remove the A-LSD which seems to be another giant pain in the ass too.

How crazy would it be to remove the entire rear drive assembly and replace it with a R33/R34 GTR frankenstein kit, while keeping the OEM stuff in storage?

I have done some reading and research, but haven't come across a thread where someone replaced the R32 front diff with a R34 centre, and the video covering Motive garage and Andrew's 6-speed swap into his R32, but he keeps his 4.11 final drive ratios.

Edited December 30, 2021 by Diomedes

[Duncan]

This kind of gets right to the heart of the problem.... my understanding is the R34 diff centre is too large for the R32 sump casing.

[Diomedes]

Really? I presumed they were the same size. Might have to go the R33 GTR non-vspec rear diff route then.

 

Was really hoping that wouldnt be the case.

[GTSBoy]

Just....swap the new old engine onto your existing sump/diff and cut out all the heartache? Close up the original engine with the 2WD sump in the shed, where it doesn't matter whether it's got a diff or not. Win?

[Diomedes]

Yes, that is the most pain-free option. Was just hoping there was easy way to swap a few parts over and have 2 complete 3.545 ratio front diff/sumps.

Ever heard of anyone using the Tomei 3.692 Final Gear set?

[joshuaho96]

On 12/30/2021 at 4:15 AM, Diomedes said:

Yes, that is the most pain-free option. Was just hoping there was easy way to swap a few parts over and have 2 complete 3.545 ratio front diff/sumps.

Ever heard of anyone using the Tomei 3.692 Final Gear set?

https://www.gtr.co.uk/threads/wtb-pinion-and-ring-gear-of-front-differential-bnr34.572998/

You could try and contact these people to see if they still have it. I believe in the R34 if you want to match the gearing of the R32/R33 for better engine response the closest match is the Nismo final drive: https://www.nismo.co.jp/omori_factory/original_menu/final_g/index.html

The Tomei 3.692 final drive is an in-between between the OEM 3.545 that drops 120 kph to about 2800 rpm and the 3.916 that raises it to about 3050 RPM. 

[Old man 32 GTR]

On 30/12/21 at 11:15 PM, Diomedes said:

Yes, that is the most pain-free option. Was just hoping there was easy way to swap a few parts over and have 2 complete 3.545 ratio front diff/sumps.

Ever heard of anyone using the Tomei 3.692 Final Gear set?

If you want 3.545, contact Neat gearboxes, they make them, may even have them on the shelf. 

[Diomedes]

On 1/1/2022 at 4:59 AM, joshuaho96 said:

https://www.gtr.co.uk/threads/wtb-pinion-and-ring-gear-of-front-differential-bnr34.572998/

You could try and contact these people to see if they still have it. I believe in the R34 if you want to match the gearing of the R32/R33 for better engine response the closest match is the Nismo final drive: https://www.nismo.co.jp/omori_factory/original_menu/final_g/index.html

The Tomei 3.692 final drive is an in-between between the OEM 3.545 that drops 120 kph to about 2800 rpm and the 3.916 that raises it to about 3050 RPM. 

Thanks for the info, going to get in contact and see if the guys on the UK GTR site still have those parts. Could get lucky!

The Nismo final gearset looks nice, but also costs about 5 grand, without shipping 🙃

On 1/1/2022 at 8:33 PM, Old man 32 GTR said:

If you want 3.545, contact Neat gearboxes, they make them, may even have them on the shelf. 

Have any experience with these guys? What is their work like? Any truth to their claims of making the OEM parts stronger with their treatments?

[Diomedes]

Also, thanks all for the info, really helpful!

[GTSBoy]

On 1/3/2022 at 3:54 PM, Diomedes said:

Have any experience with these guys? What is their work like? Any truth to their claims of making the OEM parts stronger with their treatments?

Sam at Neat knows knows his shit. He's done good diff work for me.

[Old man 32 GTR]

On 3/1/22 at 6:54 PM, Diomedes said:Have any experience with these guys? What is their work like? Any truth to their claims of making the OEM parts stronger with their treatments?

Shot peening is a process that has been around for a long time. Like I said, I’ve had my front and rear ring and pinion gear done. My diff and gearbox guy has been using Neat for many years and vouched for them. I’ve spoken to them over the phone. They were very friendly and informative. I’ve got the gears back and they look good, once my car is back together I’ll see how they hold up. 
but as you can no longer buy the front ring and pinion gear, (other then second hand) it’s good to know you can buy new from there guys, they state the material they use to make the gears is a higher grade, therefore stronger and all their gear sets are shot peened. 

[GTSBoy]

On 1/5/2022 at 9:24 AM, Old man 32 GTR said:

all their gear sets are shot peened

I'd like to think that they've been looking into cryo treating also. I must ask them. Norwood Automatics have been cryo treating input shafts on Ford (and other) autos to help them hold up in Barra drag applications (and other high torque combos). Proven to help.

[Diomedes]

I'll definitely have to hit them up in the future then. Want to keep the standard 6-speed, sounds like sending it to them for some work will be good to help with reliability and longevity.