I’ve been looking for a 4.2 XKR back box to no avail and am now considering getting the standard back box modified - knocking out blanked off pipes and welding into the existing two outlets via electric valves so I can have it loud or quiet.

Before I start I just wondered if anyone knows definitively what the box/pipes are made of? Look too well preserved to be mild steel, possibly 304 or some other stainless alloy?

 

Even with the valves fully open all the time, the exhaust is not loud. Normal driving around town is plenty quiet and silent on the interstate. I wouldn't go to the extra trouble to fit valves. I removed the vacuum pump on mine, "while I was in there", and honestly don't notice a big difference.

 

^^ Same here. I don't have vacuum valve connected on my XKR back box (permanently open) and the exhaust note is not loud with normal driving. It gets throaty when you put your foot in it, but otherwise not loud at all. It might be worth the wait and search for an XKR box and not go to the trouble of cutting up your XK box.

 

If anybody has a 4.2 exhaust they’d be willing to sell I’d love to have a chat but none have come up for sale in the two weeks I’ve been searching. There are some 5.0 XKR’s exhausts knocking about but they’d need modding. Thought I’d try modding my standard one in the meantime.

 

to each their own. IMO, many modified exhausts sound “immature”.
In reading your requirement, why not just replace the fuse. Do you have the technical description of the active exhaust?
Have you replaced the front muffler?

 

He has an XK, no fuse to pull. His exhaust valves are normally closed, opened only by exhaust gas pressure.

 

I missed that as the thread seemed to meander between an xk or xkr…. Thanks.

 

@3MSW

Found this on the marketplace today. https://www.jaguarforums.com/forum/market/281452

 

except for shipping costs!


wj

 

360 km, that's barely a day-trip.

 

SC (USA)~ UK?
wj

 

Seller: Gosport, PO12, United Kingdom

Buyer/OP: Lancashire

 

My bad!
I skipped the first poster's addy...thought it was luv2fly.
wj