Overview of Jag differentials
#21
I am running a Quaife in my XJR and in fact it greatly improved the way that the traction control intervenes, it's much less intrusive than before. A huge improvement.
Where did you get the idea that you need to disable the traction control? That is simply not true...
#23
If anything, the LSD would mean that the TRAC system sees less
of the types of inputs that would engage TRAC in the first place.
Unless, the TRAC tries to kick in faster than the LSD reacts
because it is essentially an electronic system. Then, it might be
possible that they end up fighting each other.
of the types of inputs that would engage TRAC in the first place.
Unless, the TRAC tries to kick in faster than the LSD reacts
because it is essentially an electronic system. Then, it might be
possible that they end up fighting each other.
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kulddy (02-04-2016)
#24
#25
Same with mine, now that the Quaife is installed I don't ever see the DSC engage at all.
The torque biasing type are a gentle engagement, and don't "lock" in the way that a clutch type does, so the DSC won't even know it's there.
I could imagine that a clutch type that was set up to be loose such that it would grab could cause problems. I have no experience with this, but if you had an LSD that allowed wheelspin before it engaged, then I could see how the DSC might come into play.
The torque biasing type are a gentle engagement, and don't "lock" in the way that a clutch type does, so the DSC won't even know it's there.
I could imagine that a clutch type that was set up to be loose such that it would grab could cause problems. I have no experience with this, but if you had an LSD that allowed wheelspin before it engaged, then I could see how the DSC might come into play.
#26
Me fighting the TRAC is what got my car to the frame shop. ON/OFF/ON/OFF condition. Snapped my foot off after it over rotated on a sprinkling right turn at light. I know what caused it, TRAC sensor on left front pulled too tight and disengaged. New paint stripes on street. Snapping throttle off caused momentary stall, increasing my steering effort. The MM Torsen 2R LSD 8.8 will fit right in, add the cooler and I'm good to go!
#27
The one thing I am unsure off with the ATB units and DSC, is indeed as said that they could work counteractive, so when the dsc decides to brake one wheel, the ATB unit will automatically transfer torque to that wheel, as that is how they work. Now this fighting may not be directly noticeable, unless you maybe could compare track times with and without DSC, as I would assume you would be quicker without with a ATB unit considering the possible fights.
Therefor I actually think that the clutch type ones work better with traction control as the above situation doesn’t apply as they lock both wheels at the same time.
As an example, one of my biggest annoyances was when taking a sharp 90 degree turn going left (or right) on a T crossing. Here the traction control would even kill power for half a second if I want to accelerate to fast. Pretty dangerous when you try to get quickly on the road and other cars are coming! This I also had with the Quaife unit, and could have been a result of the fighting mentioned, but with the clutch type unit I have now, I can go really aggressive in these turns with traction control on without it reducing power, that’s a BIG difference.
This may be more hairsplitting for normal driving and I fully agree that an ATB unit on itself is already a great (almost must have) addition over the open diff!
Therefor I actually think that the clutch type ones work better with traction control as the above situation doesn’t apply as they lock both wheels at the same time.
As an example, one of my biggest annoyances was when taking a sharp 90 degree turn going left (or right) on a T crossing. Here the traction control would even kill power for half a second if I want to accelerate to fast. Pretty dangerous when you try to get quickly on the road and other cars are coming! This I also had with the Quaife unit, and could have been a result of the fighting mentioned, but with the clutch type unit I have now, I can go really aggressive in these turns with traction control on without it reducing power, that’s a BIG difference.
This may be more hairsplitting for normal driving and I fully agree that an ATB unit on itself is already a great (almost must have) addition over the open diff!
#28
I think that there is probably a difference in the DSC systems between a 2000 model XKR and a 2005 model XJR. In my XJR i've had no DSC issues with the Quaife, perhaps because the DSC is a little bit more advanced? I don't know, just speculating.
The good thing is that there are clutch-type LSD's available that bolt straight into the diff of an X100 XKR. We don't have that option on the later cars.
The good thing is that there are clutch-type LSD's available that bolt straight into the diff of an X100 XKR. We don't have that option on the later cars.
#29
The 8.8" centers only fit in the S-Type diff up to 2002.
Your avatar is an X100 XKR, they are a totally different diff, not Ford.
#30
At the risk of being contradicted by a corner case, clutch
type LSD are always preloaded to some degree. Thus,
they are never completely uncoupled from side to side.
As for snap lifting off the gas when trouble is sensed,
you just don't do that.
There is an old saying ... you lift, you die.
type LSD are always preloaded to some degree. Thus,
they are never completely uncoupled from side to side.
As for snap lifting off the gas when trouble is sensed,
you just don't do that.
There is an old saying ... you lift, you die.
Last edited by plums; 02-06-2016 at 01:09 AM. Reason: ocd sp
#31
Many thanks to Plums and Cambo! I already have a quote coming from Quaife with the shipping. S, OK, so that's definite no. And yes I drive like you Cambo. I never life, just modulate. This case just caught me by surprise, my fault. I incorrectly was surprised when the engine started to die. I thought it was because I snapped the throttle off, thinking back, that might have happened after the back end got loose and the car started to die. I may have been trying to makeup for the loss of power which made the steering slow/impossible. This makes perfect sense. I will drive around the town and twisty roads with it off. Leave it on for pleasure drives with the wife when judicious throttle use is needed anyway. Never had this on a freeway onramp. Just remember it dying on tight corners at slow speeds.
New mantra......leave the TRAC OFF, DO NOT LEAN ON THE TRAC, USE YOUR SKILLS!!!
New mantra......leave the TRAC OFF, DO NOT LEAN ON THE TRAC, USE YOUR SKILLS!!!
#32
#33
Here is some more info about possible difs for the XKR:
https://www.jaguarforums.com/forum/x...lsd-xkr-84143/
Unfortunately OS Giken isn't making them until they can build 5 units. Other bad news is that the Gripper clutch type one is also now about the same price as the Quaife. When I bought that one it was much lower in price, possibly as I was the 1st.
So considering your post about the price for the Quaife, it leaves you only one option which is the x300 diff, which can be built in with some mods. There are some threads about this.
https://www.jaguarforums.com/forum/x...lsd-xkr-84143/
Unfortunately OS Giken isn't making them until they can build 5 units. Other bad news is that the Gripper clutch type one is also now about the same price as the Quaife. When I bought that one it was much lower in price, possibly as I was the 1st.
So considering your post about the price for the Quaife, it leaves you only one option which is the x300 diff, which can be built in with some mods. There are some threads about this.
#34
#35
The Quaife QDF3W is the diff centre to suit all 8" diffs in Jaguars.
Originally they listed it only for the X150 XK/R 4.2, but it's the same diff in the S-Type, X350 XJ, early XF's, Lincoln LS, etc...
I have a QDF3W installed in my 2005MY XJR...
As for which is better, a geared (Quaife, Torsen, etc) or a traditional clutch type, there are many opinions on this...
What I can tell you...
A Quaife never locks both wheels together like a traditional clutched diff (not necessarily a good thing though)
A Quaife does not wear out like a clutch type (the clutch plates wearing over time).
Sometimes with the Quaife you get the feeling that it's bouncing the torque back & forth between each rear wheel, which can be a bit of a wierd sensation...
If you are used to drifting around corners in a RWD car with a clutch-plate LSD, the Quaife requires a different technique to do the same thing, because the rear axles are not locked together.
But let me put it this way. A Quaife is a MILLION times better than an open differential.
It's been so long since I had a car with a traditonal clutched diff, it's hard to really make a comparison between the two anymore. But Avos has tried both in his XKR, he prefers the clutch type. I'm just happy to not have an open diff anymore!
Originally they listed it only for the X150 XK/R 4.2, but it's the same diff in the S-Type, X350 XJ, early XF's, Lincoln LS, etc...
I have a QDF3W installed in my 2005MY XJR...
As for which is better, a geared (Quaife, Torsen, etc) or a traditional clutch type, there are many opinions on this...
What I can tell you...
A Quaife never locks both wheels together like a traditional clutched diff (not necessarily a good thing though)
A Quaife does not wear out like a clutch type (the clutch plates wearing over time).
Sometimes with the Quaife you get the feeling that it's bouncing the torque back & forth between each rear wheel, which can be a bit of a wierd sensation...
If you are used to drifting around corners in a RWD car with a clutch-plate LSD, the Quaife requires a different technique to do the same thing, because the rear axles are not locked together.
But let me put it this way. A Quaife is a MILLION times better than an open differential.
It's been so long since I had a car with a traditonal clutched diff, it's hard to really make a comparison between the two anymore. But Avos has tried both in his XKR, he prefers the clutch type. I'm just happy to not have an open diff anymore!
#36
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jackra_1 (12-12-2016)
#37
#38
Assuming my axle shafts are usable with the s-type differential I am looking at about $700 to $800 for the S-type clutch conversion minus any bearings.
I can get a QDF3W for around $1500 in the US and not worry about import duty.
I would be buying used parts for the S-type conversion the condition of which will be unknown.
Using the Quaife I use my existing components that I believe are in very good condition and no worries about the prop or axles.
For a fairly major conversion, in my mind, I am leaning Quaife.
I can get a QDF3W for around $1500 in the US and not worry about import duty.
I would be buying used parts for the S-type conversion the condition of which will be unknown.
Using the Quaife I use my existing components that I believe are in very good condition and no worries about the prop or axles.
For a fairly major conversion, in my mind, I am leaning Quaife.
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paydase (02-25-2017)
#39
However the propshaft is compatible.
If you want to make the 4.0L diff conversion, you need the diff and the axle shafts / half shafts.
Then swap the gears out of your diff into the 4.0L one, along with the LSD.
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jackra_1 (12-14-2016)
#40