Jump to content
Volvospeed Forums

Permanent Awd Instead Of Haldex


markroemers

Recommended Posts

Hi there,

My Volvo XC90 V8 needs a new read diff. I will have it changed next week, but started to wonder about more mods for my Volvo.

Has anyone tried to change it to a real permanent AWD system like the Audi Quattro? I want this because I want less understeer.

Question 1:

Would it be possible? I cannot find how the power from the front end it distributed to the rear.

Is there another diff or is a basic 50/50 split and does the Haldex reduce the torque getting through to the rear wheels?

IF there is a central diff, can I change it for a Torsen diff? Torsen is a mechanical torque distribution diff with no electronics.

Regards Mark

Link to comment
Share on other sites

It's an XC90, nobody would ever do that for a DD XC90. If it was a 240, then it might be worth discussing crazy mods since they'd be 99% easier and actually possible.

The worst part of the Volvo AWD system on your car is the fact that it uses a splined collar to transfer power to the angle gear, not a transmission specifically designed to be AWD. It's basically a FWD transmission with some clever engineering to make it AWD, but it isn't the most rugged, and you wouldn't want it working 100% of the time in a 50/50 distribution setup.

Link to comment
Share on other sites

Audis with a transverse engine (A/S3, TT, A4, etc) use a Haldex based system.

Models with a longitudinal engine (S4, RS5, S6, etc) use a Torsen- based system that is very robust and capable of sending 80+% torque to any given end of the car.

A number of P2 R guys have had great success welding the trans output collar to to the angle gear input shaft. This prevents the splines on the collar from stripping. The major downside to that method is a different (more expensive) component of the AWD system (angle gear or front diff) becomes the failure point and not the comparatively cheap collar.

Link to comment
Share on other sites

Audis with a transverse engine (A/S3, TT, A4, etc) use a Haldex based system.

Models with a longitudinal engine (S4, RS5, S6, etc) use a Torsen- based system that is very robust and capable of sending 80+% torque to any given end of the car.

A number of P2 R guys have had great success welding the trans output collar to to the angle gear input shaft.

This prevents the splines on the collar from stripping. The major downside to that method is a different (more expensive) component of the AWD system (angle gear or front diff) becomes the failure point and not the comparatively cheap collar.

Though it's unrelated to OP's question... couldn't red locktite be used for nearly the same effect? I wondered if I should have added anything to it when it had it apart a few years back.

Link to comment
Share on other sites

Audis with a transverse engine (A/S3, TT, A4, etc) use a Haldex based system.

Models with a longitudinal engine (S4, RS5, S6, etc) use a Torsen- based system that is very robust and capable of sending 80+% torque to any given end of the car.

A number of P2 R guys have had great success welding the trans output collar to to the angle gear input shaft.

This prevents the splines on the collar from stripping. The major downside to that method is a different (more expensive) component of the AWD system (angle gear or front diff) becomes the failure point and not the comparatively cheap collar.

A4's are longitudinal. even with the FrontTrak, the A4's and A6's are longitudinal. TT'S and A3's are the only Haldex systems used. friendly correction :)

Link to comment
Share on other sites

  • 3 weeks later...

Exactly. Why do you want to have to accelerate hard into every turn that you make? Permanent 4x4 mode will cost you more gas.

You could, hypothetically, program it to keep the haldex locked up all the time. The question is, why would you want it to? For normal driving you want the rear to just be freewheeling.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...