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Agree with the above, and I've told Micky this before.
 

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Discussion Starter · #1,022 ·
Micky, what he's saying here has nothing to do with ease of changing the"severity" of the LSD action. He's just saying he builds them out of BMW bits, and that he can set it up for serious competition, or much less aggressive for road use with occasional track days.
So you won't be doing easy changes of plates in the LSD before and after trackdays, as I said above.
He's saying he can build it to your requirements, so either a soft action for the road, or a very hard action for the track. You can't have both, changing the action, means removing the diff and changing the number of plates inside, every time .
Also bear in mind that plate type LSD's wear out quite quickly.
A ZF LSD typically used in historic cars such as Escorts, Opel Manta's, Ascona's, Kadetts, Hillman Avengers Alfa's etc will typically last 5000 miles in competition, and they begin to lose their effectiveness in about 15000 miles of road driving . The friction surface on the plates wear out.
After that they need a rebuild to restore the effectiveness of the limiting factor.
Ask any owner of a 105 series Alfa 2000 GTV, they all came with a ZF type LSD as standard.
The plate type LSD's are all adjustable for effectiveness, the common ZF types are set for the road at 25%, by inserting more plates, you can get 75% effectiveness.
In my experience, having had both, you wouldn't want to use a 75% lsd on the road. I've attached an exploded view of a typical Drexler diff, that is constructed very similar to the ZF and Salisbury type "clutch plate" mechanically operated ones.
View attachment 8352
Thanks 911

Thank you for your very helpful observations.

I have just texted MRD to ask if the diff is fixed in competition mode or whether it is adjustable. If so I can create a "one size fits all" setting which would do for both road and occasional track days!

Because the car is always going to be a low annual mileage car I don't have a problem with some maintenance intervals.

Cheers
Micky
 

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Micky, if it is a plate type diff, it is of course adjustable, but only by taking the diff out, stripping it, and either adding, or removing plates to make it more or less aggressive in action.
 

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Discussion Starter · #1,024 ·
Micky, if it is a plate type diff, it is of course adjustable, but only by taking the diff out, stripping it, and either adding, or removing plates to make it more or less aggressive in action.
Hi there

I have just had a response from MRD to my question and the diff has been designed fixed with a preload of 40Nm.

M
 

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That means nothing without an explanation to you whether that setting is for occasional track use (and also good for the road without being too harsh), or otherwise Micky. Did they elaborate ?
 

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Discussion Starter · #1,026 ·
That means nothing without an explanation to you whether that setting is for occasional track use (and also good for the road without being too harsh), or otherwise Micky. Did they elaborate ?
I Whatsapped the question:-

"Is the diff fixed in competition mode or is it adjustable"

The answer was "No, fixed with a preload of 40Nm"

If you bear in mind that all of the cars receiving this diff are pure racing cars it makes sense.

Micky
 

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That's what worries me, you may find it's horrible for the road. Only time will tell. Hope I'm wrong.....
 

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Discussion Starter · #1,028 ·
Hi
Thanks. Yes I hope for the best but I’m confident Mathias would swap the diff for one of the 4 Quaife diffs that he has as surplus ones!
Actually, I may be in good situation 🤔
M
 

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That may well be a better solution all round.
 

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What was the main reason for switching to the Drexler from the Quaife?
You may have explained it already, but I was probably still at junior school back then :)
 

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Discussion Starter · #1,031 ·
What was the main reason for switching to the Drexler from the Quaife?
You may have explained it already, but I was probably still at junior school back then :)
Hi Steve

Great question.....:unsure:!

MRD had 2 race cars that had suffered broken diffs. The OEM standard variety. This was about the time I was brining the Quaife to fruition.

I had already established a relationship with MRD through seeing the Junior Cup details through a post on this forum. So one day, Matthias asked me to sell them 2 diffs to track test, as a possible replacement for the OEM version.

Unknown to me at that time, they were also talking to Drexler about a diff that they could test against the Quaife!

Mathias sent me a text with the results showing that for track use, the Drexler was head and shoulders above the Quaife and reduced track times by 2 seconds per lap. Also was superior to the Quaife in every other department.

When he told me he was placing an order for 30+ diffs in early January, instinctively, I asked him to add my name to the order! Mathias told me the eye watering cost but told me not to worry about it as they had the few unsold Quaifes that I had forwarded to them to use as "currency" to be swapped for any desirable Junior Cup parts.

So that's it basically. :)

Micky
 

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One thing that will knock seconds off your lap times is a bit of professional instruction.
When I did my first ever track day at a very wet Castle Combe I managed to grab a 15 min session with an instructor.
Couldn’t believe how he shaved around 5 or 6 seconds off my lap by explaining how to drive properly.
Could be worth thinking about Micky boy if you want to extract everything your project car will one day offer.
 

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Discussion Starter · #1,033 ·
One thing that will knock seconds off your lap times is a bit of professional instruction.
When I did my first ever track day at a very wet Castle Combe I managed to grab a 15 min session with an instructor.
Couldn’t believe how he shaved around 5 or 6 seconds off my lap by explaining how to drive properly.
Could be worth thinking about Micky boy if you want to extract everything your project car will one day offer.
Thanks Sean

I fully intend to have some track instruction on the UP GTI as I want to explore the potential to the max. On the road i am probably an average driver.

I am quite excited to see what the "pros"think of the car!

M
 

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Discussion Starter · #1,034 ·
Thanks Sean

I fully intend to have some track instruction on the UP GTI as I want to explore the potential to the max. On the road i am probably an average driver.

I am quite excited to see what the "pros"think of the car!

M
I just found this post on a car forum from someone who has installed a Drexler and is reporting back with some feedback.

Driving impressions Update:

Today I had the chance to test the Drexler LSD on some twisty hills. At the end, I really needed some motions sickness pills. The car pulls so hard out of corners like you wouldn't believe ! I really don't think I can take more lateral acceleration than this

When exiting corners hard, the exit is very "clean" with no unwanted fishtailing. The LSD transitions are very smooth, I can't feel them. If the traction is good, the car just pulls straight out of the corner like it is on rails. If the traction surface is not very good, you get some drifting but very natural and correctable.

However, I did try to accelerate hard on a wet section of the road (Nitto 555R rear tires), with DTC on (DTC button pressed once). The car goes sideways, and if you let off the throttle, it comes back in line but it does so more violently than with the open diff. I don't think it's a good idea to do this on snow or at higher speeds. Like everyone recommends, it's not a good idea to suddenly let off the throttle with an LSD. However it's not nearly as bad as I read in other reviews.

I feel that my car is now "complete". Without the LSD there were numerous occasions when the car seemed underpowered, but now I don't get this feeling anymore.

Micky
 

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It's a rear drive car!
You will not have anything like what is described, but should expect that you can accelerate out of a corner with less inside wheel spin!
 

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RWD LSD very, very different to FWD. Characteristics are unbelievably so.
You can't take anything from this and expect that it translates to FWD Micky.
 
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