I've read a lot of threads on the Quaife differential. Lots of talk about installation, bearing acquisition and seals etc but not a lot of talk about the benefits. The electronic traction control kicks in rather abruptly at a standing start on this car. Lot's of brake dust on the rear wheels after a spirited drive in the mountains.

I'm not new to torsen diffs, I installed one on my 1990 Toyota Celica GTFour RC and it improved cornering at the limit on the power. Obviously in loose grip situations it's far superior to an open type. My XKR will never see the snow.

How does it effect the electronic traction control (T/C)? How does the T/C react to the diff? Do you only see benefits with the T/C off? What quantifiable benefits have you seen?

This is a $2000 upgrade on a car that probably should have had one in the first place but that's another rant. It's a fair bit of money and I want to spend it wisely.

Thank you in advance!

 

I have heard that the LSD will kick in before the traction control does, which would be nice!

You may consider upgrading your tires if you don't want all that expense. With my old Hankook Ventus V12s, the traction control would come on constantly, but I switched to new Sumitomo HTR ZIIIs and now it rarely comes on.

 

Don't have an XK myself, but I did put a Quaife in my XJR, which also has an open diff from the factory.

It's a totally different car with the Quaife in.

With the DSC on you still get the abrupt power cuts if you go too hard off the line (but now it's both wheels spinning ) but I do not notice the rear brakes activating under spirited driving anymore, of course you can drive with the DSC off and just let the diff sort it out, which it does, quite well.

The diff does not "fight" with the DSC, which was a concern that turned out to be unfounded. It's not a cheap upgrade, but worth it IMHO...

 

No direct experience but here's an article about some of the benefits:
LSD study shows theraputic benefits of psychedelic drug - BelfastTelegraph.co.uk
;-))

 

Having grown up in San Francisco in the 60's...that was the first thing that came to mind when I saw the title.

Having owned cars with posi (not Jags), I'd think twice. Great for traction off the line or if you have to pull a boat trailer up a launch ramp, but my experience was too much sliding around turns

 

The electronic traction control (ETC) operates based on wheel slip, i.e. a wheel going around faster than the car's reference speed shows it should. In the XK, ETC first tries braking the spinning wheel, then asks the the ECM to reduce torque if braking isn't helping. If you have an LSD, that should happen less frequently, so ETC should cut in less often.

Of course, the 5.0 XKR has an electronic LSD, so there is some interaction between the ABS module which handles ETC and the Active Damping module which controls the diff. That's not the case in other models.

 

Born, raised and educated in Berkeley, thanks for the flashback...

 

Not the benefits of LSD, lol!

Posi is Chevy's trade name for a limited slip differential. I think I'm going to go ahead with the Quaife order. I'm not going to change my all seasons as this is my daily and a 15,000 (or less) mile tire is not practical. I went with the Nitto Motivos and so far so good. I hate the car will be down for a few days. Looks easy and I'll definately install the drain plug trick.