To diff or not to diff.

[TheHulkGB]

I have a 78 260z 2+2 that I’m planning on doing an LS swap too.
I know some people may find this unacceptable but I yearn for the sound of a V8!
I’ve been told that my current diff is a R200 long nose. I wanted to know if there’s any point in swapping to a short nose as I’m wanting to use these suspension parts from T3
https://technotoytuning.com/nissan/260z/complete-r200-short-nose-r230-rear-end-conversion-z-car
(Everything except the coilovers) I’m going with BC racing.
I’m also going to be running the CV axles from ZCar Garage
https://www.zcarblog.com/2018/06/08/performance/parts-z-car-garage-cv-axles.html
Any advice form someone running a setup like this would be much appreciated.
Thanks

 

[Alphabettispaghetti]

Can’t help with that, however how are you getting on with the body?

 

[jonbills]

short nose r200 has the advantages of being cheap and available and shorter (so perhaps slightly stronger)
But if your existing r200 is ok, I don't think it's worth changing.
the TTT kit doesn't require you to swap to the short nose r200 does it?

 

[Albrecht]

If you're going to be using an LS engine, it will be worth considering final drive ratio (and Open or LSD) as part of the diff question.

Stock UK market manual transmission GRS30 was equipped with a 3.7:1 R200

 

[RyanT]

R200 long nose is more than strong enough and won’t ever really be the weak link in the driveline. I’ve got one in my LS swapped 240Z, 3.54 ratio - good choice of helical / plate diffs etc.

 

[Ian]

I would avoid the short nose as with that kit from T3 the front mount for the short nose diffs in poorly designed as it gives quite a lot of leverage force and many have found that its not solid enough with big power, enough that many have had to change from it.

Long nose R200 is plenty strong, I run near enough 500hp and 490lbft through mine with no issues and many are still running one with up to 800hp.

 

[AliK]

Long nose R200 is plenty strong,.

 

[Robbie J]

If you are doing that put an R34 GTT Diff in, it has LSD. It might need a rebuild but they are £400 on ebay

need to build up the CV's they did it on mighty car mods with different shafts etc

 

[Mr Tenno]

Just as a point to consider, if you're changing all the engine, suspension, drivetrain etc. You won't be able to change the gearbox or steering without falling foul of this: https://www.gov.uk/vehicle-registration/radically-altered-vehicles

 

[Robbie J]

Just as a point to consider, if you're changing all the engine, suspension, drivetrain etc. You won't be able to change the gearbox or steering without falling foul of this: https://www.gov.uk/vehicle-registration/radically-altered-vehicles

it's a point-based system if you keep the same hubs and suspension design etc you don't need to this

 

[Alphabettispaghetti]

it's a point-based system if you keep the same hubs and suspension design etc you don't need to this

Technically that'd still 'fail'. its very grey though, also you'd have to get inspected. However with the way the worlds going it's getting more likely.

 

[Albrecht]

If you are doing that put an R34 GTT Diff in, it has LSD.

Everybody else who has answered has recommended he sticks with the long nose R200 (which he's already got), but you recommend a short nose R200? What ratio is the GTT diff, and is it plate type or viscous LSD?

I don't know what kind of driving duties this car will be subjected to (especially bearing in mind its a 2+2), but the weak links in the chain for an LS swap will be the driveshafts/UJs/CVs and - especially - the rear hub castings and half shafts. All the more so after that particular previous owner had his spanners and Hammerite in near proximity...

I'd be wanting to inspect and blueprint all that at the very least. Maybe try to source some as-immaculate-as-possible rear struts/hub castings to use for the BC conversion?

 

[Robbie J]

Everybody else who has answered has recommended he sticks with the long nose R200 (which he's already got), but you recommend a short nose R200? What ratio is the GTT diff, and is it plate type or viscous LSD?

I don't know what kind of driving duties this car will be subjected to (especially bearing in mind its a 2+2), but the weak links in the chain for an LS swap will be the driveshafts/UJs/CVs and - especially - the rear hub castings and half shafts. All the more so after that particular previous owner had his spanners and Hammerite in near proximity...

I'd be wanting to inspect and blueprint all that at the very least. Maybe try to source some as-immaculate-as-possible rear struts/hub castings to use for the BC conversion?

The R34 GTT is a lot tougher and has LSD, you have lots of options on replacement LSD or rebuild it. Likewise, there are stock CV joints (depends on what hubs) with just replacement shafts (likely can be made in the UK) it could work out cheaper than sourcing all the bits from the US + maintainable from stock parts bin. The Oz lot got free T3 but used an R34GTT diff, but I'm sure he knows this

 

[Albrecht]

The R34 GTT is a lot tougher and has LSD

A lot tougher than what? Tougher than a long-nose R200, or tougher than any other variant of short-nose R200?

What ratio is the GTT(?) diff, and what type of LSD?

 

[Robbie J]

A lot tougher than what? Tougher than a long-nose R200, or tougher than any other variant of short-nose R200?

What ratio is the GTT(?) diff, and what type of LSD?

pre 00 were R200V 4.083 and later R200H 4.111
Viscous LSD but as I said as they are used for drift cars lots of LSD options and types

Toughness? The open Diff of a long nose R200 with stock internals is not going to match a GTT Diff with LSD? Stock they take 500BHP

 

[Albrecht]

pre 00 were R200V 4.083 and later R200H 4.111

You recommend those ratios for the characteristics of an LS engine?

Toughness? The open Diff of a long nose R200 with stock internals is not going to match a GTT Diff with LSD? Stock they take 500BHP

As I asked, why are you recommending the GTT short-nose R200 over and above any other variant of short-nose R200?

 

[jonbills]

Even a standard l24 can break the roll pin of an open r200 diff with hard starts, so if surviving "hard starts" are a requirement @TheHulkGB an LSD probably is required, and then a shortnose R200 (of the right ratio) with LSD might be more financially attractive.

 

[Albrecht]

...and then a shortnose R200 (of the right ratio) with LSD might be more financially attractive.

I think the final drive ratio will (should) be a key point in the selection, and the quoted 'GTT' diffs seem to be going in the wrong direction ratio-wise in my opinion.

A 3.54:1 ratio long-nose 200 (stock equipment on Automatic UK RS30/GRS30 models) with a Quaife helical LSD conversion will be a bolt-in (less faff than short-nose) and could accept the ZCG CV axles @TheHulkGB has cited in his first post.

 

[Robbie J]

I think the final drive ratio will (should) be a key point in the selection, and the quoted 'GTT' diffs seem to be going in the wrong direction ratio-wise in my opinion.

A 3.54:1 ratio long-nose 200 (stock equipment on Automatic UK RS30/GRS30 models) with a Quaife helical LSD conversion will be a bolt-in (less faff than short-nose) and could accept the ZCG CV axles @TheHulkGB has cited in his first post.

likely cost a lot more than the using mainly proven stock parts from the backend of a skyline

 

[Albrecht]

likely cost a lot more than the using mainly proven stock parts from the backend of a skyline

He's already got a 3.7 R200 in the car. If any of this is about "likely cost" I'd say the long-nose R200 is winning on a 'Bird In The Hand' basis...

So you're still recommending a 4.08 viscous or 4.11 helical diff for an LS-powered car?

As I asked, why are you recommending the GTT short-nose R200 over and above any other variant of short-nose R200?

?