PistonHeads.com Forum

RE: BMW M135i: PH Fleet

Thursday 2nd November 2017

BMW M135i: PH Fleet

Oh what a difference a diff makes...



Twice in one week I found myself making use of the M135i's newly-fitted limited-slip differential, but each time the circumstances were very different. On the Thursday I was at Bruntingthorpe - the vast airfield in Leicestershire that's effectively now an enormous storage facility for new cars and old planes, with a bit of a test track attached to it. I was there to drive a Nissan GT-R for an Autocar feature, but the photographer was knocking about in my M135i and it would have been daft not to have a squirt in the tricked-up BMW.


I've driven enough non-LSD equipped M135is on track to know how frustrating they can be. Get on the throttle mid-corner and you might bonfire the inside rear tyre, or you might get good drive towards the exit, or it might slide neatly and progressively. No way of knowing which. With the Quaife diff in place, however, you can make the car behave exactly how you want it to, be that neat and positive drive to the exit, or the full yeehah dorifto with both tyres on fire and the throttle wide open. It really is a vast improvement.

The other occasion, the following Saturday, was somewhat less exciting. I had reason to abandon the car on a muddy grass verge - the things you do when chasing Wales Rally GB... - and had it not had its LSD I'm certain the M135i would have spun one of its rear wheels uselessly until it had buried itself in the gloop.


In fact, the truth of it is you don't need to be on a test track or in the boonies to feel the benefit of the LSD. On the road you appreciate how little the car now relies on its traction control system and how, when nobody's looking, you can play with the balance of the car on the throttle. I don't mean the big hero slides that might cost you your licence, but those cheeky little tail wiggles on a roundabout or in a tight bend that make you giggle to yourself.

Birds charges £2,033 for the LSD, with fitting taking just a couple of hours - and while the diff was going in they also fitted a short shift kit. Whereas before the gearshift was a touch ponderous, it's super direct and mechanical now. I think it suits the nature of the car. The guys also modified the clutch pedal to add a little heft to it, which I don't mind when I'm having a bit of a blast but could do without in stop-start traffic. The short shift kit costs £532, the clutch pedal mod £113.


Chasing the world's best rally drivers around Snowdonia was a stern test for the M135i, not least because it was loaded up with the better part of 400kg of people and stuff. Rear seat passengers did want for legroom on the four-hour return motorway journey, but on Snowdonia's stunning mountain roads the car was still great fun to do drive. For those of us sat up front it was relaxing and comfortable on the M5, too. Following a gravel rally really is a mucky past time, though. Mud everywhere. The M135i will need a proper wash soon.

So the chassis is sorted, thanks to the Bilstein dampers and Eibach springs, and the Quaife LSD is doing its thing. One last trip to Birds beckons, when we'll see about getting more power out of that turbocharged six-cylinder. I reckon 385hp should do the trick.


FACT SHEET
Car:
 BMW M135i
Run by: Dan Prosser
Bought: July 2017
Mileage: 33,300 total, 2,300 this month
Purchase price: £17,500
Last month at a glance: Dan gets a dose of LSD and loves the effects

Previous reports:
'You could get an M135i for that' - so we have!
Shockingly good improvement with new suspension fitted

Author
Discussion

Scottie - NW

Original Poster:

732 posts

158 months

Thursday 2nd November 2017
quotequote all
Fairly amazing really that it came without a LSD as standard.

Even 20 years ago rwd cars with decent power came with them standard.

What type of LSD is fitted, viscous/helical etc?

mylesmcd

1,822 posts

144 months

Thursday 2nd November 2017
quotequote all
Scottie - NW said:
Fairly amazing really that it came without a LSD as standard.

Even 20 years ago rwd cars with decent power came with them standard.

What type of LSD is fitted, viscous/helical etc?
Mr Harris remarked it was to keep separation between the M2 and the 135i/140i. Tbf, in the ones I have driven I have never got near the edge to need an LSD.

Lovely cars!

MustardCutter

207 posts

45 months

Thursday 2nd November 2017
quotequote all
Scottie - NW said:
What type of LSD is fitted, viscous/helical etc?
Birds fit the Quaife ATB.

R33FAL

211 posts

93 months

Thursday 2nd November 2017
quotequote all
Scottie - NW said:
Fairly amazing really that it came without a LSD as standard.

Even 20 years ago rwd cars with decent power came with them standard.

What type of LSD is fitted, viscous/helical etc?
Same as the C63... 450hp, no LSD. Amazing.

Scottie - NW

Original Poster:

732 posts

158 months

Thursday 2nd November 2017
quotequote all
MustardCutter said:
Scottie - NW said:
What type of LSD is fitted, viscous/helical etc?
Birds fit the Quaife ATB.
I know it's Quaife, the article says that, but that is the manufacturer as opposed to the type of LSD?
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kritter86

115 posts

60 months

Thursday 2nd November 2017
quotequote all
Birds paying for the PH Christmas party this year by the looks of it!

s m

15,748 posts

128 months

Thursday 2nd November 2017
quotequote all
Scottie - NW said:
MustardCutter said:
Scottie - NW said:
What type of LSD is fitted, viscous/helical etc?
Birds fit the Quaife ATB.
I know it's Quaife, the article says that, but that is the manufacturer as opposed to the type of LSD?
It's a helical gear torque apportioning diff

cerb4.5lee

9,240 posts

105 months

Thursday 2nd November 2017
quotequote all
mylesmcd said:
Scottie - NW said:
Fairly amazing really that it came without a LSD as standard.

Even 20 years ago rwd cars with decent power came with them standard.

What type of LSD is fitted, viscous/helical etc?
Mr Harris remarked it was to keep separation between the M2 and the 135i/140i. Tbf, in the ones I have driven I have never got near the edge to need an LSD.

Lovely cars!
A LSD has much better traction advantages and you don't need to be driving silly to benefit from it, I think they should be standard on all powerful cars, the LSD is great fun though as well if you do fancy having some fun.

Superlightdaa

35 posts

43 months

Thursday 2nd November 2017
quotequote all
The whole kit is high up on my wish list for my LCI M135. Just wish BIRDS was closer to the NE England.

Tomatogti

276 posts

94 months

Thursday 2nd November 2017
quotequote all
mylesmcd said:
Scottie - NW said:
Fairly amazing really that it came without a LSD as standard.

Even 20 years ago rwd cars with decent power came with them standard.

What type of LSD is fitted, viscous/helical etc?
Mr Harris remarked it was to keep separation between the M2 and the 135i/140i. Tbf, in the ones I have driven I have never got near the edge to need an LSD.

Lovely cars!
Yes it definitely needs one and yes it's to differentiate it from the full fat M cars (doesn't have 4 pipes or a bonnet bulge either). I've just changed my right rear tyre as it was through all the rubber on the inside whilst the centre was only worm a couple of mm and this is just road use. So i think it should be the first upgrade people make. Having had a couple of kids whilst owning it I couldn't justify the outlay but had (a few of) my numbers come up then I would have been straight to Birds. It's got plenty of power so doesn't need a chip really.

cerb4.5lee

9,240 posts

105 months

Thursday 2nd November 2017
quotequote all
R33FAL said:
Same as the C63... 450hp, no LSD. Amazing.
That's always baffled me too, my old 200sx couldn't even manage 200bhp as standard...yet it still came with a LSD from the factory.

culpz

2,587 posts

37 months

Thursday 2nd November 2017
quotequote all
Scottie - NW said:
Fairly amazing really that it came without a LSD as standard.

Even 20 years ago rwd cars with decent power came with them standard.
It would have only hiked the price up of the car significantly though. BMW played it clever and made the Golf R/Audi S3 look expensive in comparison. Well, the standard model with no options, at a smidge under 30k, anyway.

Also, the M135i is not a proper M car and more of an M-Lite. So, they clearly needed to leave scope for the proper M car, which currently resides with the M2.

tomcrowther

100 posts

58 months

Thursday 2nd November 2017
quotequote all
Tomatogti said:
Yes it definitely needs one and yes it's to differentiate it from the full fat M cars (doesn't have 4 pipes or a bonnet bulge either). I've just changed my right rear tyre as it was through all the rubber on the inside whilst the centre was only worm a couple of mm and this is just road use. So i think it should be the first upgrade people make. Having had a couple of kids whilst owning it I couldn't justify the outlay but had (a few of) my numbers come up then I would have been straight to Birds. It's got plenty of power so doesn't need a chip really.
If you've mullered the inner shoulder of your tire and the remainder is still okay then I'd suggest you've got problems that aren't related to an open diff

fido

13,105 posts

180 months

Thursday 2nd November 2017
quotequote all
cerb4.5lee said:
That's always baffled me too, my old 200sx couldn't even manage 200bhp as standard...yet it still came with a LSD from the factory.
Traction control helps to some extent - if it can brake individual wheels then you have an electronic locking diff - though it sounds like the M135 doesn't do this or cuts power when what you want is power to both wheels.

james_gt3rs

4,340 posts

116 months

Thursday 2nd November 2017
quotequote all
cerb4.5lee said:
R33FAL said:
Same as the C63... 450hp, no LSD. Amazing.
That's always baffled me too, my old 200sx couldn't even manage 200bhp as standard...yet it still came with a LSD from the factory.
The average driver will have traction control on though so in normal driving you'd not really feel the difference...

kiethton

9,497 posts

105 months

Thursday 2nd November 2017
quotequote all
Very interesting as off to look at M135i's this weekend for the GF

Is there a discernible benefit of that auto over the manual? - seem to be many manuals in budget to chose from but relatively few auto's!

nickfrog

8,042 posts

142 months

Thursday 2nd November 2017
quotequote all
kiethton said:
Is there a discernible benefit of that auto over the manual?
Sorry for stating the obvious but the main difference is that one is auto and the other one manual. They're both great but neither are going to be any good if you prefer the other.

Limpet

2,536 posts

86 months

Thursday 2nd November 2017
quotequote all
Think I'm going to put the Quaife LSD on my M140i in the New Year. The standard suspension isn't actually that awful, IMO but the open diff gets on my nerves, particularly when its wet.

MustardCutter

207 posts

45 months

Thursday 2nd November 2017
quotequote all
Scottie - NW said:
MustardCutter said:
Scottie - NW said:
What type of LSD is fitted, viscous/helical etc?
Birds fit the Quaife ATB.
I know it's Quaife, the article says that, but that is the manufacturer as opposed to the type of LSD?
If you know it's a Quaife then you should know it's an automatic torque biasing (ATB) helical gear based diff like all Quaife diffs. Apologies for trying to help.

fido said:
cerb4.5lee said:
That's always baffled me too, my old 200sx couldn't even manage 200bhp as standard...yet it still came with a LSD from the factory.
Traction control helps to some extent - if it can brake individual wheels then you have an electronic locking diff - though it sounds like the M135 doesn't do this or cuts power when what you want is power to both wheels.
It does use the rear brakes to mimic an LSD, but it can be quite intrusive and unpredictable as the article eludes to. It's certainly a frustration I have with mine.

Edited by MustardCutter on Thursday 2nd November 13:52

kiethton

9,497 posts

105 months

Thursday 2nd November 2017
quotequote all
nickfrog said:
kiethton said:
Is there a discernible benefit of that auto over the manual?
Sorry for stating the obvious but the main difference is that one is auto and the other one manual. They're both great but neither are going to be any good if you prefer the other.
It was more a would prefer the auto as used for commuting/fast road hoon once in a while but if the manual is £2k cheaper lfl and not horrendous to use it may be a good cost saving alternative