Hi All

We have a 2009 XF 5.0 NA with stock exhaust and 2 oval tips.

Would there be an exhaust tone and loudness improvement (subject to opinion I know) by fitting rear boxes from a similar age XFR (quad tips) with the semi-active valves?

Overall the car sounds really great, just a little quiet.

Thanks in advance.
James

 

I just bought an ‘09 XF NA and wanted a little more character as well. Darn thing is TownCar quiet. I had my shop replace the rear mufflers with Magnaflow’s, leaving the existing resonators and H pipe. They even put the oval tips back in place. Tone is about the same but %150 louder which I’m fine with. Definitely sounds like a V8 now.

I had the shop cut off just the resonators on our F Pace and while louder, it also raised the pitch, which wasn’t my goal at all.

I don’t have any experience with the XFR’s muffler but I do like the variable nature of my F Type R’s valved exhaust. You’ll have to rig a button to actuate the valves on the XF and then it will be binary and not variable.

 

The XFR variable mufflers are purely mechanical, actuated by valves which open when the exhaust gas pressure reaches a certain point.
Many XFR owners (including me!) find the default closed valve noise to be too muffled and quiet and several have "fixed" this by cutting out the valves and welding small cover plates over the remaining holes, so effectively the mufflers are permanently open.
This may be the best/cheapest option for the OP.

 

Gotcha, learned something new!

 

Very interesting. I wonder what would be the best sound rear muffler delete or forcing them permanently open. A rear muffler delete (Stage 1) would be the same as we have on the XJ which is a great sound. Looking to do that on the XK too, just not sure on the XF.

Thanks

 

A handful of XFR and XF Supercharged owners have tried the full rear muffler delete and they all report the same thing - sounds great at idle, sounds great at WOT, sounds crap with masses of drone and resonance at all other loads/revs.

 

After watching/listening to some videos on Youtube I think I agree. Rear muffler delete with straight pipes is way too harsh and bordering on annoying. Difficult to hear the lovely engine tone above anything else cracking ans popping from the rear.

Do you have any detail on the valve mod that involves welding a plate over the port? thanks.

 

No other info other than I have read that it's a fairly simply job to cut the valves out and weld cover plates over the resulting holes.
The mufflers with their attached pipes are simple bolt on / bolt off, done it many times at home, so a half decent exhaust shop can easily and quickly do it with no risk to the car.
Here's a diagram I found on-line many years ago, sorry it's in Russian, the valve is parts 2, 3 and 4 so those are what needs to be cut out.

 

Thanks for the info. I found an English version on this forum in the XF docs which are shared.
I think we are going to go for the standard XFR rear boxes, at least it is a potential improvement (looks and sound) over the stanrdard XF oval pipes and passive rear box. From there we can see how it goes.

Cheers

 

Ahh, my error. Here is where I found the doc: http://jagrepair.com/images/Electric...t%20System.pdf

Thanks