I paid a mere £500 in the UK for a cat-back straight through SS system on my X100 with no boxes whatsoever, it was LOUD! But as a V8 it rumbled as opposed to the whine you get on lesser engines.

Best of all the zaust had a lifetime unlimited mileage warranty that was transferrable to another owner

 

Advise keeping the rear muffler intact as it is an essential part of your "active exhaust", which eliminates annoying low speed cruise drone. Consider then substituting an "X" pipe for the central resonator. X Pipes are cheap and readily available from sources like Magnaflow, Dynomax and Borla. Still not loud enough? Then consider 200 cell cats.

 

+1

 

So do all X150's have active exhausts?

Why is there such an aftermarket range of systems that delete them?

 

No, no they don't. PAE (Performance Active Exhaust) was an option on XKRs, and passive exhaust was standard. Passive uses overpressure to open the outer pipes instead of using active valves.
NON-XKRs don't have any exhaust accoutrements, as there is only the two exhaust pipes.
Deleting the "Active" merely opens them 100% of the time. It is sort of a misnomer anyway, as all ACTIVE does is make the car QUIETER when not under load (or in DYNAMIC, or under 4000 RPM). Lots of XKR owners (like me) remove Fuse 19 to permanently open the valves. Basically, a quick 'delete' of the 'active' part.
THEREFORE, when deleting the Active Exhaust, that only leaves the "performance" part.

 

Umm, all XKR's have active exhausts as standard and the valves are controlled by an electric vacuum pump.

The XK's have SAM (semi active muffler) valves operated by exhaust pressure.

PAE was fitted to the XKR-S's and became optional on XKR's and means that the car has an X-pipe in place of the middle resonator and, I believe, a slightly different back box. The last few XKR's had PAE as standard.

 

According to the workshop manual, these are the pressure-actuated valves on the naturally aspirated XK silencer:


Does anyone have a drawing or photos of what that looks like on the inside?

 

I have searched for a cut-a-way photo of the insides of an XK muffler to no avail. My guess is that the small external "pucks" in the photo are actually containers for coil-like springs for internal flapper valves.

An aside on muffler valves : Dynomax at one time offered a "VT Muffler", which had an internal spring-loaded flapper. These mufflers were designed for performance and to reduce/eliminate drone. They "worked" - had them on a car for 30K miles with no issues. Nevertheless, there were complaints of spring failure and Dynomax has ceased production of the VT Muffler.

 

It was late and I was tired. I figured I mucked some of it up.
I did get the over-all concept right though.

 

Can you give a few web links for 'cheap' x pipes and 200 cell cats please?

As as they are quoting me £500 for the X pipe here in the UK plus £250 to fit (so $900 usd), is it plug n play using existing connection points, or does one have to take a saw to the existing zaust? Ask as my brother lives stateside and can give bring them over when he can bring them over in checked luggage

 

Read my build thread...

 

200 cells are very loud

My suggestion would be see how it sounds with the X pipe then look into changing out the cats

In hindsight I probably would have went a set of 400s on mine

 

 

Ditto. Mine has a warbling growl starting at 2500 and sounds absolutely amazing above 4k. I usually forget there's 2k more to go before shifting.

 

Mine is very raspy below 2500 I've got 100cells , X pipe and secondary valves permanently shut

 

There are many sources for "X" pipes. Here is one I like:

Jones Exhaust Stamped X-Pipes SXP4SS

Available at Summit Racing, a major USA vendor who ships to UK. Price is about $37US - Cheap! They slip fit onto 2.5 oem pipes. I've been buying from Summit for at least thirty years - good vendor, fast delivery and easy return policy.

 

Here is a cut-a-way picture of a F-Type V6 rear muffler with semi-active exhaust valve (spring loaded as with XK). Note the Helmholtz chamber.

https://www.jaguarforums.com/forum/p...ype-v6-188620/

 

The factory exhaust tube is 55mm OD, not 2.5"

2.25" is close to 55mm OD, but not a match

 

Cambo, Thanks for the correction.

Jones does make a 2.25" X pipe in either steel or stainless, respectively #SXP3 or #SXP3SS for $21 and $37.

Jones pipes are designed to slip inside a 2.25 " pipe. 55mm = 2.16535 ". Would the Jones slip over the Jaguar 55mm pipe?