Narrowing a Jaguar IRS

Gary · September 29, 2013, 01:52:04 AM

Hi Guys,
I have been surfing around your site and must say that it has encouraged me in the project I'm about to embark. I have just bought my first MG roadster, a 63 model with Rover 3.5 V8 installed. I need to do a rebuild as it has been neglected some what. I'm planning to install the 1977 model XJ6 rear suspension which I have.
Does anyone have any information on how to shorten the width of the suspension? maybe a link to another site.
Any help would be most welcome.
Cheers for now..
Gary

(Moderator split this from another thread, gave it an appropriate title, and moved it to the correct sub-forum.)

Gary · September 29, 2013, 02:46:55 AM

-- moved topic --

Moderator · September 29, 2013, 02:52:31 AM

Welcome to the forum! Sounds like you've got a great project. Good luck with it.

BlownMGB-V8 · September 29, 2013, 11:22:22 AM

If you don't mind some reading you could do worse than the MG-Roadmaster thread:
http://forum.britishv8.org/read.php?2,166,page=2
There's also the 340 build thread:
http://forum.britishv8.org/read.php?2,274,page=1

Those are pretty detailed. There are some other very good threads on here as well.

Jim

Richard/SIA · January 27, 2014, 02:51:10 AM

ALL about IRS conversions and narrowing.

Lots of Jag. info.

http://irsforum.boardhost.com/viewforum.php?id=1

socorob · January 31, 2014, 10:07:34 AM

There was a wheeler dealers episode, I think it was one about a cobra kit car where they narrowed a Jag IRS somewhat. It was by using a mix and match of parts from different years mainly and it made it narrower, but not sure it would have been MG narrow. Edd mentioned what parts he used to do it.

Dan B · January 31, 2014, 01:31:06 PM

Using the S-type axles shortens it by 17mm. http://www.youtube.com/watch?feature=player_detailpage&v=mvfDEdmDj8M#t=582

BlownMGB-V8 · January 31, 2014, 06:15:35 PM

Looked like a lot more than that to me.

Jim

DiDueColpi · January 31, 2014, 07:05:40 PM

I think the real # is 70mm which is 7cm or 2.75 inches.
And that is per side. So a total reduction of 5.5 inches.
Not sure that that is narrow enough but it is a significant change.
Cheers
Fred

rficalora · January 31, 2014, 07:24:36 PM

I think it was more like 70 than 17mm. What's the width of the XJ6 IRS? 70mm per side would narrow it about 5.5 inches.

BlownMGB-V8 · January 31, 2014, 09:32:00 PM

That seems much closer to what we see in the video.
Now here is the fun part. That is 1/2" more than I narrowed the XJ6 RE for installation into my roadster and the MG-Roadmaster or 1/4" more per side. Using stock parts. The pinion will not be centered in the transmission tunnel but depending on the diameter of the driveshaft and how much the handbrake bolt is dressed down it should be usable. The uprights will have to be trimmed a bit more closely but that should work out too. You'd still need the 3" flares but might be able to get by with 2-1/2 or even 2" depending on your choice of wheels and tires. And you could still get that wonderful 8" of wheel travel.

Jim

Joyridin' · May 04, 2014, 05:25:46 PM

You need to find the E type Series 1 or 2. They are 50" across.

TR6-6SPD · May 04, 2014, 07:50:26 PM

I'm using one from a 1965 XKE Series I and it measures 53 1/8" hub to hub.

Joyridin' · May 05, 2014, 07:43:48 AM

That is probably correct. They are saying the "track" width is 50", but I measured mine and it is 53" also.

Pretty narrow considering.

Jim Stabe · May 06, 2014, 06:47:54 PM

When I put the Series 1 XKE rear in my roadster back in the early 70's I had to take 1 1/4" out of each side to fit the wheel offset that was available then. Now you can get wheels with a lot more backspace and you should be able to run it without narrowing. The XKE cage bolts into the the B like it was made for it. It only took me an afternoon to have it all mounted once the battery boxes were removed. I bolted mounts through the short shelf at the front of the trunk into the rear of the cage top and made brackets that bolted the front of the cage to the shock mount holes. You have to be careful to pivot the trailing arms from the same axis as the inner pivots of the lower suspension arms, it will bind if you don't. As I recall the stock early gas tank won't fit with the Jag rear, I replaced mine with one from a Ford Falcon but I'm sure there are others that would work as well.

BlownMGB-V8 · May 07, 2014, 10:14:53 AM

That sounds right. On the RM and my roadster we had to dimple the tanks and the full cage would be worse. The tank has an internal baffle which complicates just bending it for clearance. You have the advantage of the OEM isolators which are pretty good but will probably have to adjust the ride height so that there is room below the frame rails for the knuckles, I'm guessing you might have to raise the ride height a little in the process. But check it out, it could be ok. A 17" wheel will definitely clear the upright allowing you to use that offset to advantage. Some 16's might work. As a side benefit those rims will also allow your tire to go inboard of the front steering knuckle which will allow the use of wider tires and also reduce steering effort. Win-Win. 60/70s Camaro or Malibu hubs will match the lug pattern with vented rotors (Some machining is needed, change out the studs to match) and Dodge Dart calipers match up well enough with slight ovaling of the mounting holes. Brake pads don't match perfectly but plenty good enough. We run those on the RM.

Jim