Joe, of DTS, said he messed around with our test mule differential, but doesn't feel he'll be successful transplanting a Traction-Lok (too much grinding for ultimately failure to fit). He's visiting this thread as a means to examining our pics and data. He understands the Quaife, though costlier, will work.

 

Disappointing, but none too surprising. Guess we are out of luck on the diff front... unless your pockets are deep enough for the quaife,

Who distributes the quaife in North America for the STR, and how much are they asking?

 

Thanks for all of your efforts Seth! At least know we know, looks like the Quaife is our only option...

That said, I am out, I will just deal with the computer based / TC LSD. There are alot of other / cooler things I can do with $2000+ bucks!

Oh well, glad I was able to at least to help source the test mule... I guess we will move our efforts over to the headers now then??

 

let's not jump too far yet.
Has anybody got any First-Hand-Experience on this Phantom Grip thing?

 

Well don't forget we can follow the LS guys and install the Gen I axles and diff. That would still give us a LSD and the cost would depend on how much you need to pay to get the Gen I stuff.

A supercharged LS has been running 12.8 quarter miles for over 30K miles without tearing up any rear end parts so we know strength is not a problem.
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I have no first hand experience, but I know they were kinda of a middle of the road thing with my other turbo import cars. Not quite as good as a real $2000 diff, but not as bad as the knock of Chinese parts you find on ebay.

In a "racing" environment they might not stand up to the constant abuse, but no one is road or hard core drag racing their STR, so I think it would take street duty.

Some one buy a PG and try it out.

 

Bummer. But I figured that they were having difficulty trying to get it to work. Thanks for giving it a go!

So it looks like it is down to 2 approaches:

1. Put a Gen 1 housing with LSD into the car. Means swapping the axles as well.
(I noticed that they use a different style reluctor rings between the gen 1 and gen 2 cars. Tooth count is the same, but they are different style and mounting of the sensor.)

2. Swap in a Cobra, Mark 8, or Explorer IRS rear end. (Requires new front housing mounts, a modified drive-shaft and axles.

I am heading down path #2, but it will probably be 6 months to a years before I do the swap. (I'll slowly purchase all the parts over time based on what I find out on my 2000 S-type conversion.)

I'll keep adding to this thread and post my findings as I build up my Mark VIII housing with a Torsen T-2R 31 spline rear end.

 

Thanks for pursuing this. This is one refinement I think these cars could really use. I know that some of you want this for better drag times but that's not my motivation. I just don't like the OEM solution to traction control. I'd rather spend the money on fixing something like this, if it actually works, than on just getting more boost. Control is more important to me than more raw grunt.

 

The one put in OK in England by TL Jaguar was the Quaife, and written up in JWM (Jag World Monthly magazine).

 

Given the relatively low purchase price of these vehicles now I think the issue of such a conversion becomes the price of the conversion to vehicle value ratio.

I've seen this before with other marques.

It's nice that there is such an option. Sending your pumpkin to the UK and back from the USA is not terribly practical though. It's a heavy part.

Is there an online link for that article?

 

IMO, aside from the possibilities of the "Phantom Grip", a Quaif LSD is the way to go. The Cobra/Mark VIII/Explorer option appears to be more costly and a burden than a $800 Quaif LSD, $200 for carrier bearings and seals, plus $500 install.

 

Staatsof - You can buy back issues unless they're sold out. I posted the details a while back, more than once, such as post #100 here https://www.jaguarforums.com/forum/s...g-58761/page5/

 

I agree, handling is very important. I am getting frustrated with how traction control works on my STR. When I occasionally commute with the STR, I get very frustrated on one fun tight uphill corner on my way home. There are a couple of "S" turns that are fun to push through under power. At the start of first corner is a gouge out of the road several feet long and about 3 inches wide. When I hit this spot in the road, the left tires hop slightly. This turns on the traction control light, then the car cuts power and puts on the brakes. This ruins the line through the corner. For a while I thought it was something wrong with the car, until I saw the gouge in the road. My other non-traction control cars aren't even be bothered by this sort of road condition. I believe LSD would really help in this condition to keep more even power to the wheels.

 

Ditto, Coming summer I'll look into a Quaif LSD.

 

I have another question about adding LSD to an STR. I believe the STR has 2.87 gears. I was reading some of the past posts that if you change the gear ratio then the car goes into limp mode. (Can anyone confirm this?)

I am making plans on eventually putting in a Mark VIII rear end into my STR. But I do not believe that a pinion from the Gen II STR carrier will fit into the Mark VIII housing. (Not long enough?)

Here are the 8.8 gear ratios I've found posted on other forums:
Ratios:2.26, 2.73, 3.08, 3.27, 3.45, 3.55, 3.73 & 4.10

As posted before in the forum, there are 4 rear end gear ratio's used on the S Type.
2.69:1 on manual Diesel only
2.87:1 on the 4.2 NA and all STR's
3.07:1 on various V-6 models manual and automatic
3.31:1 on most V-6 automatics except Diesel

Now I am wondering what gear ratio to use and if anyone ever figured out how to reprogram our ECM.

 

Joe, yes, she'll go into limp mode if far exceeding the stock gear ratio. IMO, for commuter/street duty...a 2.87 warmed over STR will do great against many late model muscle due to her low 4:1 first gear and protigious 500 lb/ft trq. A twin screw STR with LSD, and intake and exhaust mods will likely do a 11.89 1/4 mile on street tires. This is based on a similar modded 4.0 XJR doing 11.89 with drag radials.

 

Tijoe;
I was the one who posted that. We only have second hand reports about going into limp home mode so you are right to question this.

But it was posted by someone who had the entire rear end replaced under factory warranty. The dealership ordered a V-6 rear end and installed it in a 4.2L car by mistake and nobody noticed anything until the car was driven. So that showed all the mechanical things are dimensionally the same across the S Type line. V-6,V-8 and STR.

We have such a lack of ECM programming and knowledge that we can't say for sure if this can be changed or not. With the age and low price of our cars I don't think we will ever have it !! Time has moved on and our ECM is getting old and out of date with no further development likely.
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Yes putting a "wrong" ratio diff in our cars will definitely throw up restricted performance.

https://www.jaguarforums.com/forum/g...ids-sdd-77299/

Now if you read that thread all the way through, you'll see i've mentioned at the very end that I found someone who claims they can reprogram the TCM in the ZF 6HP26.

I've just ordered a brand new 3.58:1 ring & pinion for an LS from a Ford dealer in the US. Just waiting on shipping confirmation & then i'll be ordering a Quaife centre from TL Jaguar, and then i'll get the TCM reprogrammed.

A very complicated/expensive exercise, & i'm still not sure 100% sure if it'll work. Install is planned for 3rd week of March, will update if it's successful or not.

 

Does anyone know if there was ever a set of 2.87 gears that will fit an 8.8 differential?

Are you talking about having the TCM that sits in the trunk/boot reprogrammed, or the Transmission controller? I'll have to go back an look at the control system schematics to see what I can find.

In my swap car I wont have the same issues, because it is all being changed to a GM control system and 3:55 is the stock rear end ratio for a LS3 with TR6060 trans.

 

TCM inside the transmission, it's the "tronic" out of Mechatronic.