BMW/Titan LSD Viability

[Nigel B]

500 posts! 

[Mrp]

An update from me, collected my car from and oil service MOT and complete diff replacement (with tracsport lsd fitted) from Nick Potter on Friday. I've only done about 40 miles in it so far but the difference is incredible no clunks grinding or other noises from the diff, a complete transformation.

I'm now a full member of the Tracsport club !

I had a chance to see the oil from the original diff as Nick had drained it when it was removed and it was completely black from the worn plates.

Nick also fitted the Mazda gearbox spacer as recommended by ChrisC.

I just need to decide what to do with the cars original 3,600 mile diff assembly.

Mrp

[ScottR400D]

Ha! Join the other club...... I've got a fully rebuilt zero miles full BMW/Titan unit sat on the shelf. 

[GulfSeven]

#494 and #495

Thanks Scott.

That sound file doesn't sound much like mine to be honest - mines more high pitched, with less banging. It doesn't happen at low speed or specifically while cornering either. My previous S1 Elise whined on overrun in 5th, but the 310R does it in other high gears too (and is quite a bit more grating).

From other posts on BC it seems to be a case of TADTS due to the lack of drivetrain isolation from the chassis, but obviously having an R I have the LSD too so it made me wonder.

[ChrisC]

Can anyone confirm the configuration of the Tracsport? From the internal photos I have seen it look to be a 1.5 way or 2 way setup in comparison to the Titan 1 way.

[7 wonders of the world]

Chris the Tracsport can be specced in either 45/45 or 30/30 degree ramps. 

[ChrisC]

So it's only 2 way configuration? 

[7 wonders of the world]

The 1, 1.5, 2 manner used by some manufacturers would draw people to believe the operation is the same under drive and overrun (even is the ramp angles are the same) - which it isn't by a long way.I

In reality you always get significantly more clamping under drive compared to overrun.

 

[GulfSeven]

I finally got round to checking the preload on my diff today (by following this guide) as my car will be having its end of warranty service when it comes out of winter hibernation.

Here are the results:

• Car: 2020 310R
• Mileage: 2,400 (including 1 track day)
• Hub nut size: 42 mm
• Diff preload: 42 lb.ft

Happy with that 

[ScottR400D]

I think you'd have set a record if all hadn't been well! 

[GulfSeven]

I think you'd have set a record if all hadn't been well! 

Well indeed, but its good to have a baseline for future annual checks.

From what I've read I'm not expecting any issues with a 310R either...

[SteWi]

#511 - Don't hold your breath, see #197.

 

[GulfSeven]

Wasn't that a car with carbon plates though?

[Simon.Rogers]

We now have an exchange BMW Diff already fitted with a Tracsport LSD.

Idea is you can purchase this and have it with you for a same day swap.  Once the old one is out send it to us so we can prep the next one.

We can also do this for Ford.

[Simon.Rogers]

We now have an exchange BMW Diff already fitted with a Tracsport LSD.

Idea is you can purchase this and have it with you for a same day swap.  Once the old one is out send it to us so we can prep the next one.

We can also do this for Ford.

[ScottR400D]

What ratio is it Simon and how much? 

[Simon.Rogers]

3.91

£1544.00 + vat

£300.00 Deposit until the exchange unit is returned.

[andy_harries]

That is an excellent plan - I'm very tempted.  Just need to schedule in a free weekend as getting it on a Thursday or so, taking the old unit out and putting the new one in over the weekend and sending the other back on the Monday sounds like an excellent approach.

[ScottR400D]

Yes, it's a sound idea but only for the 5 speed box cars. The six speed is 3.64 though I guess most cars with the BMW diff have the 5 speed. 

[Andrew Willcox]

Hi, trying to make my mind up on an LSD, lots of good info on this thread regarding SPC and Titan.

Have talked to Steve @ SPC and understand the merits of SPC and understand the fit and forget economics - but I'm still struggling to justify the cost!

One option I've got is a used ZF in a Sierra housing from a Caterham... can anyone comment on how a ZF compares to a Sintered Titan in terms of noise and durability?  I think Steve said his diff was based on a ZF design...

Andrew

 

[Geoff Brown]

#520 Willcoxa - Firstly has your car got a BMW or Ford diff ? If not Ford then likely the ZF will not fit.

If a Ford diff then before fitting the ZF it is advisable that both ZF unit, CWP & the diff casing be put through inspection & overhaul to save heartache later on. Trouble is in the long run it may not come out any cheaper than fitting an SPC/Tracsport unit. Or even a brand new Titan 

From discussion here & other threads I would imagine the ZF would be more quite than a Titan with sintered plates as the majority of Titans seem to have NVH built in !  

As for durability I would put my money on the ZF unless someone knows differently ?

[7 wonders of the world]

The ZF's are excellent units with a proven design, however many used by CC came with the wrong preload and ramp angles these being 45/45 degree with 65 lb/ft preload - perfect for a lardy tintop but too hight for a 7.

There were a few that were rebuilt with correct 30/30 degree ramps and circa 20lb/ft preload.

30 degree ramps are like hens teeth even in used format though it is possible to modify 45 degree versions, I rebuilt my ZF with different bellvilles with help directly form the spring manufacturer.

The Tracsport takes the performance to another level though, and Steve will build you a cracking final drive.

The Titan or Quaiffe ATB can never be in the same league as either of the above.

 

[Geoff Brown]

#522 7 wonders - 'The Tracsport takes the performance to another level though, and Steve will build you a cracking final drive.

The Titan or Quaiffe ATB can never be in the same league as either of the above.'

You put in to a few succinct words what this thread has been trying to get over since I started it !

[BigCol]

As the latest inductee to the FCD Club, did GMc or anyone else from Caterham ever do anything but promise to investigate and consequently shrug their shoulders re BMW/Titan LSDs?

I expect a certain level of expense with consumables eg tyres, but don't think that diffs should be considered in this category!

At 10,000 miles' usage, I'm comparatively lucky but it's a chunk of expense I could do without and feel with proper design, shouldn't be necessary (my heavier, more powerful 911's LSD has done 10x the mileage and is fine!)

[ScottR400D]

FCD Club?

CC have, I am reliably informed, had discussions with  SPC but that's almost a couple of years ago and nothing's changed. 

In my experience they still deny there's a problem, even though they have previously admitted it is an issue (for owners, of course), and simply point people towards expensive, regular rebuilds. 

My SPC/BMW LSD has been in for 2 years now and I wouldn't ever consider a Titan again. Obviously can't speak for longevity yet, but it works better on every level. If I were to spec a new car I'd insist on an open diff and have a Tracsport fitted. 
 

Quotes from CC last year:

 'on the serious matter of longevity of the carbon plate – type differential, this is something that I am trying to dedicate resource to investigate. Ironically, carbon plates where introduced to reduce noise, but we switched back to sintered plates some time ago when reports of premature wear first started to appear.............I continue to have very few reports of issues but understand anecdotally that it is a wider problem than first understood and I am committed to finding a solution'.

We do not want to make ownership onerous, but in the respect of the differential it is increasingly apparent that the team at the time got this wrong....it needs to be corrected and I would be first to admit it is taking an extraordinarily long time'.

It still is taking an extraordinarily long time.