I've done a deal to P/X my 4.2 X150 XKR for a 5.0 XKR. I had a nice aftermarket exhaust on the 4.2, got a back box and a mid section with x-over pipe. I know the pipework routing for the 5.0 cars is different to run around the larger diff but is that the only difference, e.g. are things like mounting points and the rest of the pipework etc. the same? If not then I'll sell the parts I have here and get a 5.0 specific exhaust, just wondering if I could have the pipes on the existing system adapted to suit first.

 

JEPC suggests several differences between 4.2 silencers and the numerous 5.0 litre installations:




The two considerations are whether your 4.2 setup will:

1. physically fit
2. be suitable

The only way is to give it a go. If it doesn't work out, then sell it.

Graham

 

The mounting points where the rubber hangers go on the rear muffler changed on the later 5.0 from 2012 (I think, not sure the exact changeover point).
On the later car you can unbolt the metal brackets where the hangers are, on the 4.2 those brackets are welded to the chassis.
The position of the hangers might have changed a little, hard to say for sure without two cars side by side.

The exhaust tube dimensions are the same on 4.2 and 5.0, all 55mm OD

The front section where the centre pipe connects to the cat downpipes "looks" similar, but to be honest I never took any measurements, could be slightly different.

The major change being the tubing around the diff, that has to be accommodated.

The rear tubing from the rear muffler around the diff is also re-routed. So effectively everything is different around the diff, it won't bolt in without some modifications.

I only have 4.2 exhausts here at the moment, the 5.0L one I took off was taken away by the owner... so I can't easily check dimensions.

 

I have the mid-pipe that I replaced hanging in my garage. I could take measurements off of this if it would help?

 

Didn't someone on the forum use a 5L backbox on a 4.2L a couple of years ago? It needed modifying but he got it to work.