To diff or not to diff.

[jonbills]

the long nose/Quaife route is sort of capped and straight forward at about £1000, whereas the short nose route has diff, mount/cradle and driveshafts to source and to put together. might not be much cheaper than £1000?

 

[Robbie J]

It depends on the gearbox, you can get GTR ratio that's 3.54 out of a 6speed car

I'm suggesting he looks at the options. So you have an LS-powered car then?

The "drift scene" has a lot of aftermarket parts and use the Nissan parts bin with lots of abused cars with high HP. This would be better than a long nosed stock diff in Datsun 280Z which are dumped when used by the said drift cars

 

[Robbie J]

the long nose/Quaife route is sort of capped and straight forward at about £1000, whereas the short nose route has diff, mount/cradle and driveshafts to source and to put together. might not be much cheaper than £1000?

stock skyline diff's start at £400, getting a good one is the issue

 

[Albrecht]

It depends on the gearbox, you can get GTR ratio that's 3.54 out of a 6speed car

So you're not necessarily recommending a 'GTT' diff now?

I'm suggesting he looks at the options.

Up to now you've been specifically recommending 'GTT' short-nose R200s with 4.08 and 4.11 ratios.

But you're right, he does indeed need to look at the options. Optimal final drive ratio will - as I pointed out - be a key factor.

So you have an LS-powered car then?

No I don't. (?!)

However, I've built a few of these cars pretty much from scratch, have a fairly good grasp on the weak points, strong points, the options available and the importance of putting a modified car together as a well balanced package rather than an internet shopping list. Some of the other people offering their advice here know what they are talking about too.

This would be better than a long nosed stock diff in Datsun 280Z which are dumped when used by the said drift cars

I'm not sure I understand this. The OP has a UK market 260Z 2+2. What has a 'Datsun 280Z' got to with it, and who is 'dumping' the diffs out of them?

 

[Robbie J]

So you're not necessarily recommending a 'GTT' diff now?



I'm not sure I understand this. The OP has a UK market 260Z 2+2. What has a 'Datsun 280Z' got to with it, and who is 'dumping' the diffs out of them?

I know you like the merry go round of answering in detail until people give up so you have the last word. The R200 long nose comes in 280Z these are used for several drift cars and the diff's are dumped for not being strong enough

the other stuff is based on what gearbox/ratios are they using, I doubt he would use the stock gearbox? There are a lot more ratios available aftermarket for those diff's. I owned an S14a, 350Z and Skyline yes the parts are not all interchangeable but I did several upgrades with big HP engines

expecting another long response from you

 

[Alphabettispaghetti]

What gearbox and wheel/tyre size is the OP using?

 

[Albrecht]

I know you like the merry go round of answering in detail until people give up so you have the last word.

You're welcome to have the last word, but you need to be right.

The R200 long nose comes in 280Z...

Well spotted. LOL

...these are used for several drift cars and the diff's are dumped for not being strong enough

I'd suggest that if anyone is 'drifting' a Datsun 280Z, and they are 'dumping' the diffs, it will most likely be due to the fact that they are open diffs with 3.545 ratio and therefore unsuited to drifting.

A 3.545 long-nose R200 might actually be a pretty good package component for an LS-engined 260Z 2+2 street car, ironically enough.

the other stuff is based on what gearbox/ratios are they using, I doubt he would use the stock gearbox?

I would presume he'll be using the transmission that comes with the LS. I have a hunch it might be an Auto...

expecting another long response from you

Your Servant, Sir!

But I'm starting to lose hope of getting an answer to my "why GTT?" question, let alone understand what the 280Z diffs/drifters thing is all about. Maybe someone else can take a shot at getting their head around it?

 

[Robbie J]

you can change ratios in GTT, they are not that expensive
guessing on gearbox? there are adapter plates for 370Z box's and the GTT ratio might work then? I have 3.9 on mine so we just don't know do we

 

[Albrecht]

you can change ratios in GTT, they are not that expensive

So, he can buy a short-nose R200 from a 'GTT' (with a 4.08 or 4.11 ratio) for "£400 on ebay", and then change the ratio to something that came as stock equipment in another variant of short-nose R200...?

I think I'm getting the hang of this now.

 

[Robbie J]

So, he can buy a short-nose R200 from a 'GTT' (with a 4.08 or 4.11 ratio) for "£400 on ebay", and then change the ratio to something that came as stock equipment in another variant of short-nose R200...?

I think I'm getting the hang of this now.

depends on his gearbox?

 

[TheHulkGB]

Thanks for all the replies, it’s made things a little clearer. I’m planning on using 17 inch Watanabe wheels with either a T56 or TR6060 transmission.
What final drive would you recommend, it’s mainly going to used for spirited driving and car shows which will involve a lot of motorway miles. Thanks

 

[TheHulkGB]

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

So how are all these Zs driving around with RB25 and LS without issue. I don’t want to fall foul of the law but I want it to be strong enough to take 600hp. Any advice would be helpful thanks

 

[Robbie J]

So how are all these Zs driving around with RB25 and LS without issue. I don’t want to fall foul of the law but I want it to be strong enough to take 600hp. Any advice would be helpful thanks

you will be needing a R33 or R34 GTT diff then.... with 600BHP take your pick on your ratio as it depends on the gear ratios in the transmission but 4.1 should be close. You are in the Hybrid Z section really, you get less attention from Albrecht in there
As there is a good few GTT's n the UK you might as well do the skyline CV swap as well so you need to source the correct length driveshafts, i was thinking of doing that before i went STI for a cheap LSD and the Canadian CV's well I was on business 50 miles away it would have been rude not to.

Just remember the Skyline brigade treat diff's and gearboxes as consumable items so pick a good one

 

[Mr Tenno]

So how are all these Zs driving around with RB25 and LS without issue. I don’t want to fall foul of the law but I want it to be strong enough to take 600hp. Any advice would be helpful thanks

Lots of people ignoring the rules / not realising they exist.

 

[SeanDezart]

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

You're welcome to have the last word, but you need to be right.

A 3.545 long-nose R200 might actually be a pretty good package component for an LS-engined 260Z 2+2 street car, ironically enough.

Maybe he already has a 3.54 in his car……

....and this, being from a two seater, is liable to be a 3.7 : https://www.ebay.co.uk/itm/Datsun-2...9f93:g:ZxwAAOSw-VtbJkSi&LH_ItemCondition=3000 if he prefers that !

 

[Albrecht]

Maybe he already has a 3.54 in his car……

....and this, being from a two seater, is liable to be a 3.7 : https://www.ebay.co.uk/itm/Datsun-260z-rear-diff/332957851539?hash=item4d85d59f93:g:ZxwAAOSw-VtbJkSi&LH_ItemCondition=3000 if he prefers that !

If I were you, I'd go to factory literature for technical reference data over pages from 'Super Profile' books:


...and since we know our old friend Mr Muscles' car quite well (a UK market GRS30 with manual transmission) we know that it left the factory with a 3.7:1 ratio R200 differential. If it had been an Automatic, it would have had a 3.545:1 ratio.

As I was saying...

You're welcome to have the last word, but you need to be right.

 

[TheHulkGB]

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.

Is this the LSD you mentioned? https://shop.quaife.co.uk/nissan-200sx-s13-quaife-atb-helical-lsd-differential

 

[Albrecht]

Is this the LSD you mentioned? https://shop.quaife.co.uk/nissan-200sx-s13-quaife-atb-helical-lsd-differential

Yes, I believe that is the correct one for the 'Long Nose' R200 that was standard equipment on your car. Quaife will fit one to your diff for you too.

You're welcome to listen to the guy recommending short (high numerical) final drive ratios to you, but my reckoning is that even with the tall overdrive ratios in the T56 the LS will have enough torque to push against a 3.7 or 3.5 final drive ratio very effectively, and that would still leave you with 1st, 2nd and 3rd gear ratios that are actually useable. You mention motorway miles, and the 5th and 6th in the T56 will certainly eat them up even with the 3.7 or 3.5 finals.

The GRS30 is much lighter than the vehicles an LS + T56 combo are usually fitted to. There are online gear calculator programs out there where you can 'test' your combinations:

https://www.blocklayer.com/rpm-gear.aspx

 

[Albrecht]

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.

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.

^Quoted from posts #5 & #6 from this thread, as it seems some people might have missed them.

 

[Robbie J]

The fact that nobody has that setup on the forum means he will have to guess, it's not a competition, will you compensate him if the diff breaks or the ratios are wrong? No