I just purchased a 2005 XK8 and one of the first things I would like to do is give it a slightly louder voice. So before I go chasing down a shop to do the work does anyone have any suggestions? A local Jag dealership service guy highly recommended using Magnaflow over Flowmaster and he also felt that if all I was looking at doing was replacing the muffler(s) then I could just go ahead and do that without any custom pipe bending. ANY input would be greatly appreciated.

 

There are a plethora of threads on this subject in the forum. A quick search will net you hours of reading
Two common approaches ( all subject to debate about too loud , not loud enough, drone , no drone etc )

Completely remove the large central muffler and replace with X or H pipe
Remove rear resonators and replace with pipe ( Adamesh has a nice kit for this)

I like mine to be quiet so I have done nothing

 

Okay that's what I thought but when I tried to do a search for this I got tons of stuff that didn't apply to exhaust options. I must have used the wrong search criteria. I did use the advanced search.

 

DBC,

If your XK8 system is in good shape, just leave it as is and remove the little silencers and change the Mufflers to either Flowmasters or Magniflow rear Mufflers,,,They will be more than load enough......Be sure to keep your Tips.....As I recall the XK8 only has single Tips but they are made for the 2005 XK8 and are part of the look!, Any old Muffler Shop should be able to do the job! The Jaguar Guy is correct.....you want have to do any pipe bending to speak of!!! Do Not remove the Center Silencer are you not be able to sit in the Jag and enjoy it without Ear Plugs.....

Billy Clyde in Houston

 

So I'm going to do it in stages because I don't have time to get it all done at once. I'm trying to find a diagram of my exhaust system. I'm a little confused by what you said above, sorry it's probably me but There are two sets of items on the car, first there is the mufflers and then toward the back there are silencers? Is that correct?

 

DBC,

The Front Muffler, which is (5) the double Muffler up Front should be left alone...Cut the little silencers off (6) that are right behind the Double Muffler and replace with the same size pipe to fill in the area.....Then cut the Rear Mufflers (7) off and replace with the Muffler of your choice! Magnaflow or what ever you want!...Then put the chrome Tips on and match them up with the Bumper...………...This will give you a nice sounding system that is not real loud but sounds the way you want! (See Attachment Below for System) This is a easy job for the Muffler Man, so when you go to the Shop, do the entire job don't do it a little here and a little there...…………..

Billy Clyde in Houston

 

The motive in all of these exhaust modifications seems to be to make the car louder. Putting the sound issue aside has anyone noticed any performance improvement in exhaust modification?

 

I think the MacLeod exhaust has been dyno tested for a few HP, but the $/HP ratio is pretty bad; high-flow catalytic converters from Nameless are supposed to be better in that regard, but those are also pretty pricey and are custom jobs with a long lead-up to build.

 

I found an article from years back where a Jaguar engineer was explaining the design of the XK8 exhaust system. Their whole point was to tune the system to sound like a European sports car.
I find a local custom muffler shop that the local Jaguar Dealership service tech recommended.

Here's the scoop. Using American lingo, each pipe has a long 18" or so resonator, a short resonator, and a muffler. Well not really a muffler per se since they are all pass through units. Per what the Jaguar engineer said, and as a sound guy myself for 28 years, all combined they simply tune the exhaust sound to a specific frequency.
That all being said I agreed with the muffler guy and for $250 I had him remove the first long resonator and replace it with an "H" pipe arrangement. Unlike what was mentioned by one of the other guys in here, and I mean no disrespect since he sounds like an amazing Jag experienced guy, the sound is increased but still very subtle. There is no deafening sounds inside the car just a slightly louder overall sound that makes it clear my engine is not some tamped down cat with a horse bit in its mouth. There's no droning or weird V6 sound.

I'm going to continue to drive it for a while but I may take it back and have him remove the smaller resonators. If I touch the rear muffler I'll use a Magnaflow since they use much better quality materials than the Flowmaster.

I'll try to get a recording of it from the outside and also a recording inside with my sound meter. And post a link to it on my YouTube. I kind of screw up and didn't get a before recording.

 

Fellow forum member DBC: The forum is fantastic, but I've found very little in the forum on what to expect from a dealer, independent garage or dedicated muffler shop. Much of the information here concerns kits or components of the exhaust system. If you do go to a shop, as opposed to DIY, I would like to know. if the shop custom (re)built your exhaust system or gathered parts from a kit? Also, some cost information would be helpful. I have to admit that I'm clueless when it comes to Jaguar exhaust system repair or modifications and anxiously look forward to reading of your experience as I would like to know what to expect. Thank you.

 

Look at changing your cats. I went from 400 cell cats to 200 cell. The result was a much louder throatier note to the exhaust and more BHP.

 

Frankc I will definitely do that. Truck Graphics as I said a custom muffler shop should have the experience to build a system without a kit. In this case he literally just removed the long resonators and replace them with a couple of straight pipes and an "H" crossover pipe between them. As I said it was only $250 for this work. The fun is if I feel like I want to try something else like changing the Catalytic converters I can with this guy. It just depends on what I want to spend.

 

I am going to give you the counterpoint to this. ;-)

As you just got the car, take a bit of time and let the essence of the jaguarness seep into you first, and decide on the sound level later. For now, enjoy the car for what it is: a fine piece of machinery that is not really the most anything, but provides a fine mix of features resulting in a unique feel. Unless you need to repair a rusted out exhaust system, maybe consider addressing a few key maintenance items first, like a transmission service, oil cooler lines, ride height and plastic thermostat housing. Also double check everything cooling related (hoses, etc.). These well chosen maintenance items, while certainly not sexy, will pay you back a thousand times over. Then revisit the exhaust question a few months down the line. Just my thoughts.

Best of luck, and keep us posted.

 

Agreed ....when I first got mine I considered modifying the exhaust as well, but after a year of driving and enjoying the car I have decided that I like the sound just as it is It's a matter of personal preference

 

Oh, I fully understand the personal preference issue. You have to understand that I spent my youth driving my Dad's 1973 Saab Sonett III. Little tiny V4 with just glasspacks for exhaust. Then all my cars have been pieces of garbage because I put to kids through private school in the Seattle area which left no money for a real car for Dad. If one of my pieces of junk broke down I had to fix it if I wanted to get to work or anywhere else. Suddenly I have the ability to own a really nice used car. After waiting 29 years to own a car like this, and having all kinds of experience with a very wide range of vehicles and learning my desires for various options, well here I am. At this point in my life I am not waiting to see what happens. Some of you missed the fact that I have already done the first change and the sound is perfect. In fact it could be a little throatier than it is but I'm good for now. This is really easy folks, I can have it changed again if I want too, this can be undone if I don't like it.

All in all is sounds a lot nicer than the 1980 VW Rabbit Diesel I owned that had the muffler that was held on by a coat hanger and would fall off at the least opportune times. Now, that car without a muffler was horrible! Well that and without the back pressure provided by a muffler you could burn out the Valves.

 

Not sure how it on on the 2005, but isn't the long centre resonator an H pipe to begin with?

I am personally thinking of replacing the centre unit in my XKR with an X pipe and removing the very last resonators post axle.

 

If you do, no need to let us know. We'll all hear your car across the globe.

 

I've done exactly that in my XKR, and it sounds great when you're pushing it, but it drones between 1700-2100 RPM, which isn't fun when you're part-throttle just trying to keep up with traffic. I'm reinstalling the rearmost resonators to see what that sounds like; I bought the car with those removed in the first place, so I don't know what it'll sound like with just the center muffler gone and an X-pipe in its place.

That being said, DBC, the XKR and XK8 rear boxes seem to have different configurations, with the exit pipes leaving the boxes at different locations, so what works for the XKR will likely work differently for the XK8 and vice-versa.

 

When you refer to drone, I am kind of curious to know how you mean. With the factory set up I notice what I would call in my opinion a "drone" in the cabin, but it's not irritating, just turn the radio on or put the top down and it's great!

 

I have only driven two XKRs and both had the same "drone" at highway speeds when compared to my whisper quiet XK8. Also noticeably louder on acceleration. I think that it's the nature of the beast that is an XKR.

For anyone thinking of carving up their XK8 exhaust, just go test drive a local XKR for sale and see if the noise level is what you desire. Might help you decide without opening your wallet. But don't mash the pedal or you may end up buying it. The power is dramatically different.