Swap diff to 3.58: how fast?

So, it looks like I’ll be buying back an '88 I sold to a friend. He’s bought a big Range Rover, and the S is surplus.

The acceleration was never great. I was thinking I would have to do T700 swap or something. I do have a 3.58 diff from a 1992 4 litre S. Maybe that would be enough to give it some go?

Does anyone have any experience with this, or a formula for improving on the 8.5 second 0-60?

I know DD did a 3.31 swap on his XJ, and said it was worth it.

I did a 3.31 swap into a S3 XJ6, and couldn’t tell the difference,

I know for the best result, the 3.58 AND the T700 would be best.

Thoughts?

Thank you,

Rob

Kirby, yes, I did check the dizzy advance was free.

Rob the GM 700 has a first gear of 3.08 so its hard to see much to be gained unless your starting with a 2.88 axle. Easy to pencil it out. Pete

I agree, if budget allows and you plan on much highway travel.

If long distance highway-speed travel isn’t a big part of your life I’d go with the 3.58 alone and see how you like it. You can always add the TH700 into the mix later.

I find the 3.31 with the TH400 to be fine. In fact, the response at highway speed is actually very pleasing and I still manage 17-18 mpg…which is only a couple MPG less than my XJS with the 2.88

Cheers
DD

So way down the line, after i get my xjs restored, I’d like to up the performance. When you say swap to a higher ratio, are you talking about changing out the differential, or rebuilding it? Is this a major job?

In my case I bought a used 3.31 diff (off an ad here on J-L) and had Coventry West rebuild it for me.

Cheers
DD

It takes about 4 hours to pull the diff cage and all out providing the stock exhaust is on place and not welded together

Fast wouldn’t be a word that i would use when working on a Jaguar suspension.

Realistically it takes about 20 hours to go through the IRS from one end to another. i have a YouTube channel. I’m currently going through an IRS on my channel right now. Well not right now, but its my current project.

I’m editing the videos so they aren’t quite so boring.
I will be posting on the radius arm my first IRS rebuild thread. There are a couple of videos of questions

How about a link to your channel. I’d like to check it out.

I didn’t provide a link because it’s still in a Gelatin state; I’m in the process of putting a theme or make some sort of sense of randomness I’ve got going on now. I started by videoing stuff, then throwing them up on youtube. I quickly discovered that isn’t probably the best plan, since the videos haven’t gotten any comments to speak of; and as I started watching other channels that get attention, I discovered a common continuity that my videos lacked. That being said, I picked up some editing software, pulled out my film books from college and boned up on film structure & editing, and now I’m reviewing my footage to see if any of the footage can be edited into some sort of contextual format for a video AND keep it under 5 minutes.

This is an arduous process.

Currently,

  • I’m writing a script that I’ll use as channel “branding” video to give potential viewers and idea of what the hell I’m on about.

  • Editing The scary process of putting a completely assembled IRS on a bench which is no small feat when you work by yourself

  • Editing the tear down of the IRS

  • Assembling a play list

  • Producing videos while performing the tear down

  • Thinking about what order to put the videos in

    • Breaking each component into separate video

    • Putting the major components into videos

  • Wondering if I should put all aspects of the process

    • includes where to find part numbers on the Internet

    • Where to get manuals

    • ordering parts

Welcome to the mind to an adult with Attention Deficient Disorder, it’s a scary place to be. :stuck_out_tongue_closed_eyes:

Here’s a link to my channel, but like I said I’m still trying to put some order to this.

Youtube
Jag Mods Channel

I’m trying to get some videos up today.

Leave comments, or comment back here or PM me via the Forum with your thoughts and recommendations.

Thank you for your interest

Mark

I’ve been saying we needed videos since the days that meant VHS tapes. What we need today is some sort of access page on jag-lovers.org that will lead owners to the videos they need. The videos could still be on YouTube, jag-lovers.org would simply provide links to find them.

My plan is to eventually go through the XJ’s stem to stern videoing the whole process. Some bits have been reported as boring; which watching some git stand there in silence un-do fasteners is well, pretty boring. So I’m doing what I can to liven it up.

Keep you posted, you all posted.

Mark

i run a 3.73 rear gear, and the 700R4 trans truck unit, plus a large tire 275 width 18 dia.

i like it, in overdrive it comes a final ratio 2.60 to 1, so great fro cruising, and has trouble hookin up in 1 st gear.

wild%20cat%2Cburnout%20006

Now you’re talk’in! I know you’ve done lots of mods to your car though.

Did you use a John’s Cars Kit? Any glitches? I’ve done 2 for XJ6’s but never a 12.

Here’s the car,

RobIMG_0534 IMG_0538