The V8 Owners Forum -

Is it feasable to convert from inboard to outboard discs?

I own two cars both of which used Salibury Jag based IRS's that I'd dearly love to get that 4-wheel dusc brake look from the Italian exotics?

An alternative I'd thought of was substituting for an XJ40 Jag axle but maybe this is biting off more than one could chew???

Thoughts?

Thanks.

Phil

Are there some jags which use inboard and some outboard discs? (both IRS of course), I had an XJ6 a while ago which had outies, just wondering if you could do a straight swap with another model?

the hardest part would be finding a way to mount the callipers to the floating hub, the obvious way I would be looking at is finding somebody who makes steel hub carriers, I have seen them, I would think the KitCar world would be the place to look,
If you have a friendly welder, they MA be able to weld brackets to the alloy hubs, But the area needed to welds to is not that thick. and may well pull the hub out of shape.

IIRC the later Jags have the same IRS, but with outboard discs, so it shouldn't be too much of a problem to either change the whole unit for the later type, or graft the later hubs, lower arms and driveshafts on to the early diff.

Just don't blame me when it turns out to be anything but easy.......

Wiki has the answer !
http://en.wikipedia.org/wiki/File:1995_ ... bframe.jpg
Looks like the later xjs had a "crossover" unit, the later ones look much diffrent

And can be done by fitting XJ40 hub carriers to the earlier units by the sounds of it. (You're more than welcome to blame Wiki if it isn't quite that simple.....)

Thanks for all the feedback.

Something I've learned is that the late XJS 6.0's had the X300 vented discs and better calipers, Brembo's I believe.

In fact I have some of these calipers so they may finally come in handy.

The only problems, and I think they're pretty minor is that I'll need a spacer to mimic the in-bopard discs that will be removed and I've been told the lower fulcrum pin holeswill require some packing pieces.

Will have to sort out a handbrake mechanism. Something hydraulic would be far far superior to the crap Jag handbrake.

I'll let you know how I get on.

Phil

Will have to sort out a handbrake mechanism. Something hydraulic would be far far superior to the crap Jag handbrake.

Leave the inboards in place and use them for the handbrake and the outboards for footbrake

As you may know early Jag handbrakes need to be in perfect condition and adjusted correctly to work.

I'm thinking of saving some weight and replacing the inboard discs with a spacer then using an aftermarket hydraulic handbrake on one of the outboard discs.

Thanks again guys.

Phil

Correct me if I'm wrong but you wont get an MOT with a hydraulic handbrake as they creep off, thats what I was told by a guy that used to build the WRC cars a few years ago! I guess if the tester doesn't notice though it wont matter...

Hydraulic handbrakes are officially allowed, but they have to be completley seperate from the main brake system (even different fluid resevior) and fail safe also they have to demonstrate that they wont creap off. The net result is most MOT places will not pass them no matter what, and SVA likewise.
Citroen have had them on some of their cars on and off over the years, their way around it was to have a mechanical (big spring and friction "servo" on the brake shoe) that held the handbrake on until the Hydraulic system disengaged the break when you had hydraulic pressure and released the handbrake leaver (which was actually just a hydraulic valve). Fairly obviously if you lost hydraulic pressure your brakes came on, but on the relevent models if you lost pressure you lost everything so you wanted the brakes to come on
Mike

What I had in mind was use the outers for foot brake and handbrake to keep Mr tester happy then keep the inboard disc and calipers and feed that from a hydraulic handbrake then you have best of both worlds

Unless you're rallying is there any point having a hydraulic handbrake?

Guys,

Thanks for all your thoughts and feedback.

I mentioned a hydraulic handbrake earlier as I was sure I had read somewhere where a second and smaller caliper was used as the handbrake.

As I am intending to go to the hassle of converting from in-board to out-board rear discs I though what better time to try and improve on the Jag style rear 'penny washer pad size' handrake.

If I can replace the in-board discs with ali spacers then I'll also be saving a considerable weight.

I have just purchase at £50 a pop two X300 Jag rear hubs & drivershafts with vented discs + calipers - nice.

The first TVR wedge with outboard discs

Phil

I just came across this rear handbrake and wonder what all your thoughts were about such a unit?

http://www.ultima-gtr.org.uk/photo.php?pic_id=67

This is on an Ultima but this same Brembo cable operated handbrake caliper is offered by Gardner Douglas for under £200.00.

Seems cheap for a new, complete and legal handbrake - looks nice also!

Phil