Advice needed on rear end build..

Sean287

Sean287

Well-Known Forum User
The time has come and I need to consider rebuilding the drivetrain on my 240Z. At the moment I'm running a standard R180 diff, standard stub axles and shafts. Gearbox is S14a.

My car is turbo charged and is turning out 297bhp and 313lb ft of torque. From everything I have read I am guessing at some point something in this setup is going to fail...

I don't do track days and I don't intend to break the 1/4 mile record, I use the car for spirited Sunday drives and am quite mechanically sympathetic toward it.

I'm looking for some advise on installing an R200 and which final drive to go with. I also need help in determining what to do about the stub axles and drive shafts (CV or not to CV). I intend to fit a LSD and again am not sure to go with a Quaife or a Nismo CLSD.

A garage has offered to build and install an R200 3.54, 260Z stub axles, standard drive shafts and Nismo CLSD for £2500. This appears to very expensive compared to what other people have achieved. Is this realistic and what do you think I should budget for?

Thanks in advance for any advice.

Sean
 
Ian

Ian

Club Member
How does your car feel with the current final drive? Does it need shorter or longer gearing?


Your stub axles may be ok, guessing its track work and hard drag launches that would cause them to break, or running more hp than 300.

U-Joint shafts may be ok, but imo if you can budget it then why not change to CV joints.

If you aren't going to do any track days and aren't hardcore drah head then I think for the road a Quiafe would better as it will be much smoother than a CLSD.
 
Rob Gaskin

Rob Gaskin

Treasurer
Staff member
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Sean, what problems are you having? If one wheel is spinning lift your foot, it's far more satisfying driving with skill and feel and spending the £2.5k on a good holiday.

You know what they say - if it ain't broke don't fix it.
 
moggy240

moggy240

Insurance Valuations Officer
Staff member
Club Member
I would just fit a standard R200 and still use your stub axles and halfshafts
 
Sean287

Sean287

Well-Known Forum User
Ian said:
How does your car feel with the current final drive? Does it need shorter or longer gearing?


Your stub axles may be ok, guessing its track work and hard drag launches that would cause them to break, or running more hp than 300.

U-Joint shafts may be ok, but imo if you can budget it then why not change to CV joints.

If you aren't going to do any track days and aren't hardcore drah head then I think for the road a Quiafe would better as it will be much smoother than a CLSD.
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It's a pretty rapid machine with 3.9 final drive. I was thinking to go for 3.54 as it would exploit the engine on boost rather than franticly banging through the gears. It would also give better motorway cruising.

Ultimately I wanted to do the CV conversion, but I just get lost reading all the forums and posts. I'm not sure what to buy and how it all fits together. I know you've got a pretty impressive set up Ian and it would be great if you could walk me through your shopping list with costs etc (you know how easy it is for me to get all this stuff if it comes from over the pond). I was thinking that Quaife would be best for my type of driving as I've run one before on old MGB roadster with a V8 conversion that I owned.
 
Sean287

Sean287

Well-Known Forum User
Rob Gaskin said:
Sean, what problems are you having? If one wheel is spinning lift your foot, it's far more satisfying driving with skill and feel and spending the £2.5k on a good holiday.

You know what they say - if it ain't broke don't fix it.
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No problems at the moment Rob apart from accelerating through the gears like there's no tomorrow. (not a bad thing really)

You're right about a holiday! I've just read an awful lot about R180's being to weak for this kind of torque and that the 240 stub axles are a weak point on the car. Maybe I'm just being to paranoid. I definitely see the benefit of a LSD. I'm guessing the R200 and 260Z stub axles would be the cheapest part of this conversion with the LSD being the most expensive. I just get confused with regards to which R200 I should be using and which stub axles and spline count etc...

Is something like this suitable:

Datsun R200 Open Differential | eBay

I also see that Wyn is selling some 260Z stub axles for not a lot of money. Would these be worth the investment?
 
R

rallymanDP

Well-Known Forum User
The Quaife LSD works well on any Competition 'Z' for Tarmac work & gives a progressive grip which helps to balance the application of power through a corner. Should be able to buy a 3.7 R200 and have the LSD fitted for around a £1,000. You will also need a different Mounting Bar - the Kameari one is virtually bulletproof & costs around £400.
.
Look up the website of Wolf Creek Racing for a well-engineered CV kit which is complete with all the fittings, etc., to do the job, and is easier than doing the late 280ZX Tripod conversion, and moreover uses new metal, as opposed to 30 year old stuff. Costs around the £650-£700 including shipping, Duties, etc.

The standard 240Z Driveshafts will fail pretty quickly with over 250bhp going through what is, again, 40-year old metal, made with all the budget limitations of production costings.
 
P

pmac

Well-Known Forum User
Look up the website of Wolf Creek Racing for a well-engineered CV kit which is complete with all the fittings, etc., to do the job, and is easier than doing the late 280ZX Tripod conversion, and moreover uses new metal, as opposed to 30 year old stuff. Costs around the £650-£700 including shipping, Duties, etc.
Click to expand...

However the kit from Wolf Creek uses cheap generic CV joints and shafts that are made from chocolate and splines machined by Stevie Wonder.
QV a pair of proper case hardened shafts with the correct splines machined on will set you back £300 on their own..
 
R

rallymanDP

Well-Known Forum User
Peter, the only other option are the ones that Lawrence had made for the Safari cars - don't they cost around £3,000 a set ?
Kevin Bristow had some shafts made up by a specialist Transmission Company to replace the Wolf Creek ones and they failed last weekend at Goodwood, I am told, first time out.
Have you heard of any of their kit failing ?
 
S

status

Well-Known Forum User
Im running a Quaif,3.1 motor,using late 280 box and all the bits that come with it,you are welcome to come round and jack up my Zed and have a look,im in herts ,bit of advice if going for a Quaife,take it to their place at brands and let them fit it in the diff as there are some people that have let other people do it and had problems
 
Rob Gaskin

Rob Gaskin

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Staff member
Site Administrator
Sean287 said:
No problems at the moment Rob apart from accelerating through the gears like there's no tomorrow.
Click to expand...

Ok, so a 3.7 R200 would help. What size tyres are you using, can you up the profile?

If you were competing in the drag challenge or rallying I would agree with the other's that you need to strengthen the drive-train and fit an LSD but perhaps for your driving a change of overall gearing may be enough. It's usually the sudden shocks that cause the breakages.

Only you know your driving style but from your original post I'd guess that you look after your transmission.
 
Alphabettispaghetti

Alphabettispaghetti

Club Member
Subaru's run r180's with loads of hp and torque though a high streess 4wd drive train without issues, maybe a newer r180 with a plated diff, some flange adapters mated to new custom made driveshafts?
 
johnymd

johnymd

Club Member
Lots of different advice hear and plenty for you to think about Sean. I think most will agree that a turbo car with your sort of power will be no fun at all with no traction and one wheel continuously spinning. Not to mention the fact that that's what breaks r180's and is also the weak point on an r200. So, LSD is the first thing on your list and you may as well go r200 while your about it. You will need a 260z mustache bar and rear crossmember. A quaife is around £650+ vat and £100 for quaife to fit it(well worth them doing the job). You could stick with your old uj's at your power and there are reports of them being fine. In that case you will just need diff output stubs off a 260 with uj's. The stub axles Wyn is selling are also a worthwhile upgrade but you could probably get away with your current ones. I prefer the 3.7 ratio in my car but that's personnel preference.

At 300hp I feel your at the point where you could keep a lot of you existing stuff as long as it in good condition but moving to an LSD is a must or you won't be able to make the most of the cars potential. Moving to cv's is a whole load of expense and hassle that I don't think you need and I'm not sure they are any stronger.
 
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