Is X drive the same as haldex

Is X drive the same as haldex

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Discussion

PorkRind

Original Poster:

3,053 posts

205 months

Tuesday 11th February 2014
quotequote all
Is it just a rebranded version of haldex?

Monty Python

4,812 posts

197 months

Tuesday 11th February 2014
quotequote all
No - Haldex works as FWD until slippage occurs, then drive is sent to the rear wheels (at least in the case of Volvo). X-Drive is permanent with 40:60 front:rear split under normal conditions.

dododo

734 posts

127 months

Tuesday 11th February 2014
quotequote all
Unless I dreamt it I read on PH also that x-drive is electronic 4x4 rather than the mechanical version with haldex?

Liquid Tuna

1,400 posts

156 months

Tuesday 11th February 2014
quotequote all
Monty Python said:
No - Haldex works as FWD until slippage occurs, then drive is sent to the rear wheels (at least in the case of Volvo). X-Drive is permanent with 40:60 front:rear split under normal conditions.
dododo said:
Unless I dreamt it I read on PH also that x-drive is electronic 4x4 rather than the mechanical version with haldex?
Well it can't be both, surely? Either it's part time or full time. So which is it?

TooMany2cvs

29,008 posts

126 months

Tuesday 11th February 2014
quotequote all
http://en.wikipedia.org/wiki/BMW_xDrive

BMW's current xDrive has a wet-plate central diff capable of adjusting the torque split between the front and rear. Normally, it's 60:40 R:F, but it can go to 100% either end. I s'pose you could call that "part-time"...

No, they don't buy it in from Haldex.

richs2891

897 posts

253 months

Tuesday 11th February 2014
quotequote all
I'm pretty certain x drive is considered permanent with a 40:60 F to R split and it can vary the amount between the front and rear axles depending on the amount of slip detected.
Haldex is primevally 2 wheel drive most common is front wheel drive and send power to the rear upon slip detected. It can be configured to be rear wheel drive and sending power to the front.
Which is better - not sure !

Horse Pop

685 posts

144 months

Tuesday 11th February 2014
quotequote all
A lot of 4WD systems are conceptually similar to Haldex if you look at it like that.

Edited by Horse Pop on Tuesday 11th February 13:57

Ozzie Osmond

21,189 posts

246 months

Tuesday 11th February 2014
quotequote all
All I would add is that a large number of modern performance diffs are "hybrids" using a mixture of technologies.

jon-

16,509 posts

216 months

Tuesday 11th February 2014
quotequote all
richs2891 said:
I'm pretty certain x drive is considered permanent with a 40:60 F to R split and it can vary the amount between the front and rear axles depending on the amount of slip detected.
Haldex is primevally 2 wheel drive most common is front wheel drive and send power to the rear upon slip detected. It can be configured to be rear wheel drive and sending power to the front.
Which is better - not sure !
Surely x drive?

The Vambo

6,643 posts

141 months

Tuesday 11th February 2014
quotequote all
richs2891 said:
Haldex is primevally 2 wheel drive
They cavemen were really ahead of their time hehe

scherzkeks

4,460 posts

134 months

Tuesday 11th February 2014
quotequote all
Monty Python said:
No - Haldex works as FWD until slippage occurs, then drive is sent to the rear wheels (at least in the case of Volvo). X-Drive is permanent with 40:60 front:rear split under normal conditions.
Haldex Gen 2 (which you refer to) is usually set up as a 90/10 or 85/15 (Audi) config and then sends torque to the rear as needed based on driveline slip. It is largely a traction aid.

Haldex Gen 4 and 5 are different, and serve to improve dynamics as well as traction. The clutchpack is preemptively locked at 50/50 on acceleration or in sports driving, and driveline slip in this condition typically pushes the car into rear bias. Essentially, the systems function like the old Torsen 50/50s, but with better fuel economy for the times where the AWD does not need to be as active and the ability to transfer up to 100% of torque to either axle.

X drive is 40/60 and varies traction based on slip, and the latest versions are pretty good, but BMW does not offer a sport suspension on X-drive models.

Dave Hedgehog

14,565 posts

204 months

Tuesday 11th February 2014
quotequote all
scherzkeks said:
Haldex Gen 4 and 5 are different, and serve to improve dynamics as well as traction. The clutchpack is preemptively locked at 50/50 on acceleration or in sports driving, and driveline slip in this condition typically pushes the car into rear bias. Essentially, the systems function like the old Torsen 50/50s, but with better fuel economy for the times where the AWD does not need to be as active and the ability to transfer up to 100% of torque to either axle.
it can also torque vector by applying braking to individual wheels

underphil

1,246 posts

210 months

Tuesday 11th February 2014
quotequote all
what system does the Countryman use?

The Nur

9,168 posts

185 months

Tuesday 11th February 2014
quotequote all
scherzkeks said:
Haldex Gen 2 (which you refer to) is usually set up as a 90/10 or 85/15 (Audi) config and then sends torque to the rear as needed based on driveline slip. It is largely a traction aid.

Haldex Gen 4 and 5 are different, and serve to improve dynamics as well as traction. The clutchpack is preemptively locked at 50/50 on acceleration or in sports driving, and driveline slip in this condition typically pushes the car into rear bias. Essentially, the systems function like the old Torsen 50/50s, but with better fuel economy for the times where the AWD does not need to be as active and the ability to transfer up to 100% of torque to either axle.

X drive is 40/60 and varies traction based on slip, and the latest versions are pretty good, but BMW does not offer a sport suspension on X-drive models.
Top quality post, chap.

chrisx666

808 posts

261 months

Tuesday 11th February 2014
quotequote all
The Nur said:
scherzkeks said:
Haldex Gen 2 (which you refer to) is usually set up as a 90/10 or 85/15 (Audi) config and then sends torque to the rear as needed based on driveline slip. It is largely a traction aid.

Haldex Gen 4 and 5 are different, and serve to improve dynamics as well as traction. The clutchpack is preemptively locked at 50/50 on acceleration or in sports driving, and driveline slip in this condition typically pushes the car into rear bias. Essentially, the systems function like the old Torsen 50/50s, but with better fuel economy for the times where the AWD does not need to be as active and the ability to transfer up to 100% of torque to either axle.

X drive is 40/60 and varies traction based on slip, and the latest versions are pretty good, but BMW does not offer a sport suspension on X-drive models.
Top quality post, chap.
+1, very well explained.

Earthdweller

13,563 posts

126 months

Tuesday 11th February 2014
quotequote all
They do I have an x drive with sport suspension

Scuffers

20,887 posts

274 months

Tuesday 11th February 2014
quotequote all
The Nur said:
scherzkeks said:
Haldex Gen 2 (which you refer to) is usually set up as a 90/10 or 85/15 (Audi) config and then sends torque to the rear as needed based on driveline slip. It is largely a traction aid.

Haldex Gen 4 and 5 are different, and serve to improve dynamics as well as traction. The clutchpack is preemptively locked at 50/50 on acceleration or in sports driving, and driveline slip in this condition typically pushes the car into rear bias. Essentially, the systems function like the old Torsen 50/50s, but with better fuel economy for the times where the AWD does not need to be as active and the ability to transfer up to 100% of torque to either axle.

X drive is 40/60 and varies traction based on slip, and the latest versions are pretty good, but BMW does not offer a sport suspension on X-drive models.
Top quality post, chap.
Except it's just marketing speak...

Haldex is a clutch, and as such, cannot torque split as such, all it can do is join the front and rear axles together (with a variable degree of slip toothed rear)

A differential can deal with front and rear axles at different speeds

To try claim otherwise is just showing mechanical ignorance.




Edited by Scuffers on Tuesday 11th February 19:37

The Nur

9,168 posts

185 months

Tuesday 11th February 2014
quotequote all
Scuffers said:
Except it's just marketing speak...

Handed is a clutch, and as such, cannot torque split as such, all it can do is join the front and rear axles together (with a variable degree of slip toothed rear)

A differential can deal with front and rear axles at different speeds

To try claim otherwise is just showing mechanical ignorance.
Well it seemed very informative from the perspective of the ill-informed hehe

Scuffers

20,887 posts

274 months

Tuesday 11th February 2014
quotequote all
The Nur said:
Well it seemed very informative from the perspective of the ill-informed hehe
Yes very, haldex is a clutch.

Are you going to try and claim otherwise?

Go on, tell me it's not... go on...


The Nur

9,168 posts

185 months

Tuesday 11th February 2014
quotequote all
Scuffers said:
Yes very, haldex is a clutch.

Are you going to try and claim otherwise?

Go on, tell me it's not... go on...
Eh?