RE: BMW M135i: PH Fleet

[Scottie - NW]

Would this Quaife Helical ATB diff be a 1.5 way?

[SidewaysSi]

I will be getting an LSD for both my Elise (along with a UCR straight cut 'box) and BMW E36 coupe.

I like to drive sideways and having the ability to tweak the back axle on road is a big appeal. And yes, I do tend to find I do get some degree of oversteer on most journeys so for me, an LSD is vital.

On track both cars spin a rear wheel and don't allow for full power slides at the moment which is somewhat frustrating..

I run the BMW as a family car (1 year old sitting behind 5'8" wife in a rearward facing seat) with no space issues at all.

[s m]

Scottie - NW said:

Would this Quaife Helical ATB diff be a 1.5 way?

A Quaife diff doesn't lock like a plate diff so this wouldn't apply.
A Quaife diff is just apportioning the drive torque between the drive wheels dependent on the bias ratio rather than locking them together.
That's why in a Quaife diff if you have zero torque at one wheel ( airborne wheel or no friction say on sheet ice then it can only send or bias the equivalent torque to the other wheel multiplied by that ratio - as zero times anything is zero then that's how much torque is sent to the other wheel .....I.e. Zero )

[Scottie - NW]

s m said:

Scottie - NW said:

Would this Quaife Helical ATB diff be a 1.5 way?

A Quaife diff doesn't lock like a plate diff so this wouldn't apply.
A Quaife diff is just apportioning the drive torque between the drive wheels dependent on the bias ratio rather than locking them together.
That's why in a Quaife diff if you have zero torque at one wheel ( airborne wheel or no friction say on sheet ice then it can only send or bias the equivalent torque to the other wheel multiplied by that ratio - as zero times anything is zero then that's how much torque is sent to the other wheel .....I.e. Zero )

Well explained thank you, getting my head around this a bit better now.

[Toed64]

s m said:

Toed64 said:

The Quaife is a massive improvement over the OE open diff with nannies, but a Wavetrac is better, especially if you want to use a decent rear ARB:

https://www.youtube.com/watch?v=E4wY2NoJ6f8

Guess you're using a much stiffer ARB than perhaps you could with a Torsen/Quaife.

If you don't mind me asking, roughly what did your Wavetrac come in at fitted?

Actually, I have yet to fit, but I'm going for a Wavetrac having tried both. Birds are not letting people test drive their cars at the mo...but a chap I know has a Quaife on his nicely sorted 130i. His M3 rear ARB caused the inside wheel to lift and he lost traction to the point that he wondered if he actually had a Quaife fitted. He had to go back to a 15mm bar.

I don't want to drop the stiffness of the rear bar because it's really improved the high speed stability and ultimate cornering speed of my car. With some extra negative camber provided by M3 LCAs on the front and the stiff ARBs, the car does not understeer anymore, it turns in much harder and it's much more adjustable in the corners. It's now possible to tighten lines mid corner without scrubbing and washing out. The M3 LCAs make an extraordinary difference that I would highly recommend to anyone, even those that don't drive hard, because the front tyre shoulder wear is reduced and the car's roadholding is significantly better in the wet and dry. They are only about £50 each on Amazon.

The Quaife is about £2000 fitted, the Wavetrac is about £300 or so more. Regal Motorsport in Southampton will also need the car for a few days, whereas Birds offer a 2 or 3 hour turn-around.

[xjay1337]

SidewaysSi said:

I will be getting an LSD for both my Elise (along with a UCR straight cut 'box) and BMW E36 coupe.

I like to drive sideways and having the ability to tweak the back axle on road is a big appeal. And yes, I do tend to find I do get some degree of oversteer on most journeys so for me, an LSD is vital.

On track both cars spin a rear wheel and don't allow for full power slides at the moment which is somewhat frustrating..

I run the BMW as a family car (1 year old sitting behind 5'8" wife in a rearward facing seat) with no space issues at all.

While I appreciate this is PH and we all enjoy a bit of fun I think you should perhaps slow down.

"Some degrees of oversteer on most journeys"

[s m]

Toed64 said:

s m said:

Toed64 said:

The Quaife is a massive improvement over the OE open diff with nannies, but a Wavetrac is better, especially if you want to use a decent rear ARB:

https://www.youtube.com/watch?v=E4wY2NoJ6f8

Guess you're using a much stiffer ARB than perhaps you could with a Torsen/Quaife.

If you don't mind me asking, roughly what did your Wavetrac come in at fitted?

Actually, I have yet to fit, but I'm going for a Wavetrac having tried both. Birds are not letting people test drive their cars at the mo...but a chap I know has a Quaife on his nicely sorted 130i. His M3 rear ARB caused the inside wheel to lift and he lost traction to the point that he wondered if he actually had a Quaife fitted. He had to go back to a 15mm bar.

I don't want to drop the stiffness of the rear bar because it's really improved the high speed stability and ultimate cornering speed of my car. With some extra negative camber provided by M3 LCAs on the front and the stiff ARBs, the car does not understeer anymore, it turns in much harder and it's much more adjustable in the corners. It's now possible to tighten lines mid corner without scrubbing and washing out. The M3 LCAs make an extraordinary difference that I would highly recommend to anyone, even those that don't drive hard, because the front tyre shoulder wear is reduced and the car's roadholding is significantly better in the wet and dry. They are only about £50 each on Amazon.

The Quaife is about £2000 fitted, the Wavetrac is about £300 or so more. Regal Motorsport in Southampton will also need the car for a few days, whereas Birds offer a 2 or 3 hour turn-around.

Cheers, I suspected that was the case with the rear ARB

[SidewaysSi]

xjay1337 said:

SidewaysSi said:

I will be getting an LSD for both my Elise (along with a UCR straight cut 'box) and BMW E36 coupe.

I like to drive sideways and having the ability to tweak the back axle on road is a big appeal. And yes, I do tend to find I do get some degree of oversteer on most journeys so for me, an LSD is vital.

On track both cars spin a rear wheel and don't allow for full power slides at the moment which is somewhat frustrating..

I run the BMW as a family car (1 year old sitting behind 5'8" wife in a rearward facing seat) with no space issues at all.

While I appreciate this is PH and we all enjoy a bit of fun I think you should perhaps slow down.

"Some degrees of oversteer on most journeys"

Nothing wrong with that - right place and time. Besides, unlike new stuff, my cars have quite narrow tyres and low limits. Partially why I bought them...

[cbr6fs]

Isn't the ATB a TorSen type diff?

If so it will do absolutely nothing to help on wet grass

[Toed64]

cbr6fs said:

Isn't the ATB a TorSen type diff?

If so it will do absolutely nothing to help on wet grass

Yes, that's why the Wavetrac is superior to the Quaife. It's a geared, torque biasing LSD, like the Quaife, but with a with a central cam (wave) mechanism that detects loss of grip under drive or overrun and engages a plate to lock the sides.

https://www.youtube.com/watch?v=QEhLGe_M6XU

[anonymous-user]

SidewaysSi said:

Nothing wrong with that - right place and time. Besides, unlike new stuff, my cars have quite narrow tyres and low limits. Partially why I bought them...

Every day at some point I have a little bit of fun, mostly low speeds as I'm not an F1 driver and know my limits.

[SidewaysSi]

yonex said:

SidewaysSi said:

Nothing wrong with that - right place and time. Besides, unlike new stuff, my cars have quite narrow tyres and low limits. Partially why I bought them...

Every day at some point I have a little bit of fun, mostly low speeds as I'm not an F1 driver and know my limits.

Totally agree. Was on track on Monday in the Elise. Worn, old tyres made things interesting..;)

[dhutch]

Manchestergas said:

Having a plated diff fitted to my 7 at considerably more cost to the quaife atb unit at the moment (when we can find one, even brand new there like hens teeth). In the caterham world the quaife atb is frowned upon to some degree.

I think it all depends on the cars use. I have a quaife in my Westfield, just for fast road and also autotesting and it was a huge improvement over an open diff, only about £550 and basically maintenance free.

Can't compare it to a plate diff as I've never had one, but very happy non the less.

[dhutch]

Also, why is it £2000 for 135?

For the 330 E46 it's like £750 for diff and £1100 fitted.


Daniel

[s m]

dhutch said:

Also, why is it £2000 for 135?

For the 330 E46 it's like £750 for diff and £1100 fitted.


Daniel

From the horses' mouth


"
The reason why the Quaife conversion on this car (and some others) is so expensive, is that BMW have changed their fixing method, so that the crownwheel gear is actually welded to the standard open diff. So we can't just send out a Quaife kit, for the customer to install himself. So what we do is to buy in a stock of complete final drives, rip 'em apart, machine the crownwheel off the open diff, provide bolt holes into the crownwheel so that it can then be mounted onto the Quaife. So it's a lot more work, and we then also have the financial burden of carrying dozens of final drives in stock. These standard drives cost up to £1,700 each.

But it does make sense to do it this way, because we can ship anywhere in the world, and the customer only has to de-mount his final drive, mount the modified one, then send the standard one back.

The complication above adds £480+ Vat to the "normal" job.
"

[BFleming]

BFleming said:

Maybe I'll post back on here over the weekend with findings. My son is 6ft3, so it'll be interesting to see if he fits the car / car fits him!

Some pictures of my new purchase. Yes, it's a 114i SE, but there's more than enough space for the 4 of us.

[dhutch]

s m said:

From the horses' mouth

"... the crownwheel gear is ... welded to the standard .. diff...."
"

Ahh, that would do it!

Daniel

[kiethton]

Don't know if it's been partially influenced by this thread but we've (well the GF) has just bought herself an M135i to replace an ageing but well optioned 2.0 TSi Scirocco and to sit alongside my S2 Exige and CBR600 commuter tool, a pretty decent 2 person mini-fleet!

Out with the old:



Listed for sale on Thursday evening and sold on Saturday with a token £100 off asking, all in £2k better than WBAC's pre-haggle offer.

In with the new:



Huge spec:

Auto
Professional media and navigation
Harmon kardon
PDC front and back with reverse camera
M dynamic suspension
Adaptive LED lights
Tinted rear windows
Folding mirrors
Heated seats
Folding seats
Cruise control
Comfort access

On top of the standard bits (leather, climate etc.)

Little bit of an upgrade for her and bloody quick, likely leave my Exige for dead until we hit a corner.

[CABC]

Interesting that this thread isn't longer. It's all about tasteful modding to enhance the driving experience. I wonder how many standard cars could be transformed by a few '000.
Modding has bad overtones, but standard cars are leaving a lot of performance on the table. By 'performance' I don't mean 0-60 stats.

[anonymous-user]

Modified 135's seem like huge value right now