Just spoke with Eric (DTS). He's confident he can make an 8.8 Tru-Trac work in the S-Type, wether there is or isn't grinding. He'll soon mock up a LSD for one of their 8" differentials. The Quiaf is very expensive ($2000+) compared to an $825 DTS prepared unit (using our carrier). The feeling is becoming stronger that we'll soon have LSD's. DTS said they have a vested interest in us as a means of gaining a good portion of Jags with open differentials...at a modest cost.

 

It's a manual 6 speed but that's the track car. It's just when the ratios of the Getrag land with that diff don't work well at the track. The other one was a 5 speed auto and it really helped in the umph department but it also ate more gas, like 3 mpg more. I'd like to avoid that with the STR. That's all.

 

I would be interested in the LSD as well, hopefully with a group buy price!

 

Quartz, a $100 or better discount will be available for a group buy price, depending on how many orders DTS will recieve within a given time.
Bob, IMO a 3.30 final drive ratio should be adequate for both the V6 and V8. Though a lower numerical ratio multiplies torque, it can be in many cases be the death nell to a solid launch. Both a 400 chp and 650 chp twin screw STR will likely benefit more from a higher ratio such as the stock V8 2.87 or V6 3.30:1 rear. Remember; the ZF has a 4:1 1st gear ratio. If rollimg in neutral at 5 mph, slipping it into drive will cause a very noticeable rpm rise. Thankfully, Jag factored in the low 1st gear when it finalized its choice of a 2.87 rear gear. IMO, both a stock or modded 400-450 chp STR or a 650 chp twin screw STR will enjoy the 2.87 rear gear i.e At launch, more rpm can be loaded against the brakes just prior to launching the beast = Less tire slippage= lower ET.

 

How hard is it to pull the rear pumpkin?

 

Mike, depends on who and where the carrier is to be taken from the car. I'd have a shop do it on a lift. Likely a 2.5 hour job for a skilled mechanic.

 

Eh... I Don't think our electronics work to control the diff like that.
I believe the STR's DSC system simply modulates the rear brake calipers through the ABS module. It will attempt to slow down the spinning tire by modulating the brakes on that specific corner, thats it. A band-aid solution at best to an open diff.

A mechanical LSD would make a WORLD of difference on the STR and is up there with must-have mods including twin-screw and a good ecu/tcm reflash.

 

Bob was referring to the XF's electronically controlled differential.

 

It's been one of my life long desires to experience a re-flash/ twin screw ...

Hope you're correct about the effects of this mod on our old STRs. That's why I'm curious to here about the experience AVOS has had.

My FWD Mercury Sable wagon probably uses a similar system and I wonder if it also reduces power to prevent slip? When it engages I don't really notice it but then there'a lot of weight on those front wheels and whole lot less sudden, large amounts of torque to deal with.

I have a mid engine 3,400 lb 325hp car that has a limited slip transaxel and it's very effective. But I also have RWD front engine turbo charged car that develops a lot of torque suddenly and the Torsen diff in that car doesn't do all that well. Just a bit better than the Salisbury diff did.

Electronically controlled diffs and active chassis handling can be an amazingly effective system. I'm very used to driving powerful cars that have none of this but 400hp and 400 ft lbs of torque is a bit much for the STR's setup IMHO.

We shall see how well this works. I'm hoping!

 

I wounder how our lsd works? If its the same system as say an e55 amg it should still be able to cut good 60ft times. With good drag radials like m/t et streets ive seen 1.7 60ft's on the stock open diff in an e55 multiple times.

 

Doesn't the MB E55 AMG come with a LSD?

 

Nope it has the same electronic style lsd that come in our cars. For some reason i think with the dsc off in the str it turns off the electronic lsd.

 

Ours don't have any kind of lsd, electronic or otherwise.

 

The STR does not have an LSD, of any sort, electronics or not.

 

amgeater, our S-Types have non electronic (old school) open differentials. Almost finding it hard to accept that MB would put an open differential into a beast such as the E55 AMG?

 

Here are the images of the Gen1 and Gen 2 carriers next to each other from the LVC Forum. The LS guys confirmed that the Gen 2 differential case was not symmetrical and the differential in the Gen 2 is off-set further to one side with un-equal axle/spline lengths. Someone tried to put in a Trutrac and was not successful.
On the differential image you can see the gen 2 differential has a longer distance between the bearing and the gear. This requires a longer spline on the axle. I suspect at a minimum one new axle will be required if a Trutrac can be fitted.

Somewhere it was written that it was too much machining to make it worth their while. Hopefully this shop will have the equipment to be able to modify the differential and make it work. Perhaps on a short-run production basis it will be worth their effort.

GEN 2 with LSD? - Page 3 - Lincoln vs Cadillac

 

Thanks Joe. I'll bring these points up with Eric (DTS). He'll visit the thread.

 

Uh guys, do you think one of these will fit?

Eaton Detroit Truetrac Differentials 912A616 - SummitRacing.com

It's a dedicated 8.0" unit.

 

Eric (DTS) mentioned the Eaton but don't remember his comment on it.

 

If I go down the the path of putting in an LSD, I will figure out how to put in a Torsen T-R2 differential. They are much better at transferring the torque than the Eaton or TrueTrac differentials. On my 2000 conversion S-type, I am going to have to go with a Cobra or Explorer differential anyway, because I want/need to go with 3.55 gears to better match the TR6060 six speed and larger diameter tires being fitted to the car.

On my STR, I really hope this works out fitting a modified 8.8 in the Gen 2 pumpkin. If not, in a couple years, I'll figure out how to put in a Cobra IRS with LSD. If I go through the process on the Gen 1, it would be easy to repeat on the Gen 2 sub-frame.

All it takes is time and money....