My subrames have seen better times and rusted badly. Why not to upgrade to better factory option? Looks like f-type's is one piece design and ours is steel frame plus aluminium strut. Getting rid of bushings also seems like two hares kill. Does it have same geometry and mounting points?

Pics from internet:

 

I doubt it, but hey get it and see. You never know, otherwise you may need to consult frame specs that frame repair body shops use may be your best source

 

Wow! A bold proposition! I love it. Wish I had some room in the pocket to try this out with my '04 restoration. Mine sat in a gravel yard in upstate NY for two years. Subframe is rusty but not the worst I've seen. Ditching the bushings might make for a pretty harsh ride though. At the end of the day I don't really want my XJ to ride like an F-Type.

 

I've been thinking about this swap/upgrade for a while now. Since the F-Type subframe can be swapped into the XKR, it might be helpful to compare the X350 subframe vs the X150 subframe to try to get a better idea about its feasibility. It wouldn't completely surprise me if it did fit.

 

The rust on the original pictured subframe is nothing.

What do you hope to achieve? A barn find in 100 years consisting of just an F-Type sub-frame?
"Oh hang on ...it's not original"

Assuming you replace with an original subframe, a rare occurrence I think, how many subframes would you expect before the rest of the car goes belly-up?

 

ChrisMills has good a point.

Glass bead blast, then powder coat the ones you have.

Having them off of the vehicle already, & don't look all that bad, it would extend their life a great deal.

Don't get me wrong, a frame immune to rust would make our cars last a lot longer, a real plus.

 

Not sure about the OP, but my interest was purely from a performance perspective. The XJ is already a fairly lightweight car, for its class. Not much heavier than the XK, & way lighter than the F-Type. If you could move the power-to-weight ratio & give it better handling to boot, wouldn't be awesome?

 

I'm a bit puzzled here. Some months ago there was a big row in the Jaguar Enthusiasts Club magazine about rusting of the front subframe of the F-type !! AFAIK they are steel like all the others. Jaguars have apparently acknowledged this problem and people had new ones fitted under warranty.

So what subframes are we looking at in the photos ?

 

AFAIK, that was in reference to the rear subframe

 

Did this ever go anywhere?

 

Pretty sure nobody tried it. That would cost money that could/would/will be spent on something else on the car like maintenance items... or "bling" stuff

 

Estimating the original crossmember would be 30kg and based on aluminium weighing roughly a third of steel it would be roughly a 45lb reduction.

As a collective whole we do know the f type rack is a straight bolt up to the x150 subframe and looking at the suspension components of a f type they all look quite similar to the x150

The crunch would be having a breaker measuring the subframe mounting points to the body

 

After speaking to a particular breakers Ive established that the radiator support and rails are the same on the f-type .

There are 3 crossmembers available - steel, aluminium AWD, aluminium rwd obviously that's the one we are interested in .

I'll get my car up on the lift week and use a Tremel to get measurements off the xkr subframe to see if they match up as I've had another breaker send me through some pics of the f-type measurements.

For a part reference we are after T2R21964 / T2R40869 :
GX53-5019-BD / GX53-5019-BE



Approx 39" as measured by breaker