I had my center muffler removed and replaced with a X-pipe. I barely noticed a difference. In fact, I felt it was a waste of money. If I had it to do over, I'd probably leave the center muffler and remove the two in front of the rear axle.

 

Thats what I want to do Sam , remove the two in front of the axle and leave the rest as standard , I have already fitted a 05 XKR system to my 98 XK8 so I could have the genuine Jaguar XKR Quad pipes , as the rear boxes are shorter than my originals and the exit pipes straight it appears a little louder but I'd like to improve on the growl

All the best

NikasilNik

 

Removing mufflers add more noise. Replacing the cats both improves the quality of the noise and makes it much louder.

I removed the center muffler on my XK8 and added a H pipe, it sounded alright. I removed the center muffler on my XKR and added a H pipe and it sounded horrid.

 

My XKR came fitted with a one-off Nameless free flow system including high-flow cats. It sounds great. Love it. Wonderful growling rumble on-throttle; nothing more than distant thunder in cruise. It has resonators and mufflers, but no X or H pipe. However, when I spoke with the guys that designed the system they said they probably "would" have built in an X or H pipe if they'd have the time.

Properly done, the cross-overs do add performance. Locate them closer to the engine for power peak at higher RPMs; further downstream lowers the RPM at peak. On a full out race rig you can place the cross over where ever it is ideal, but in the case of modifying a production car the options for its location may be limited. Still, just as in the case of long vs. short pipe headers, regardless of what constitutes your ideal there "should" be some performance gains over the stock configuration. Someplace.

Ciao! - Jim

 

The stock center resonator has a built in crossover passage. Without it one bank can overcome the other (less smooth), less chp and trq., and the exhaust will emit a 'Braap" sound. Maintain the stock mufflers but install Magnaflow hi-flow (200 cell) cats, or Magnaflow 50 State Legal cats (outflow stock cats), Magnaflow Tru-X center muffler (built-in x-pipe). Here, smoothness, chp, and trq. are improved, along with a non-overbearing Muscular European Rap.

 

The proper Borla center muffler has an internal x-pipe crossover... at least it did when I purchased mine. They still have the same part but make no mention of it in their literature anymore. All I know is everything OEM behind the stock exhaust manifolds suck. The cats are horrible and the over the axle pipe being the worst offenders. The stock exhaust was designed to be quiet, not to be beneficial to performance.

 

Agree. Jag was def. more concerned with peace and quiet at the expense of proper flow. Hi-flow cats are at the top of the list of power enhancers on my 03 STR, really woke it up.

 

I know that this comment will offend some of us - but I gotta ask it anyway...

Has anybody out there "gutted" their cats? I mean, taken a big honkin' hammer and screwdriver and crush the material inside the cats - hollowing them out? How did that sound?

Yeah, it'll pollute more - but I live in the midwest USA - where "the wind goes sweeping down the plains" and besides, I'm wayyyy more of a heathen in many other ways!

I'm thinking of doing just that - looking for a better sound out of my "R"

Plus, of course, adding some home-made MIL eliminators to the secondary O2 sensors. (I know the circuit pictured is not for a Jaguar, but I just included it to illustrate how easy a circuit may be to build)

http://tinyurl.com/afczs4s

 

... towards someone else ... no thanks ... its the same as someone dumping chemicals into the headwaters of the Mississipi because "it'll flow downstream anyways"

 

Any car I've ever run "gutted" cats on ended up sounding raspy and hollow. I've always liked a good high-flow cat over no cats.

 

Pop on a pair of hi-flow cats (200 cell). Closest thing to running open pipe, whilst cutting down on hydrocarbons.

 

Well, Plums I can see your point - mostly because, living on the Missouri river in Kansas City - For my entire life, every day, I've been drinking the water that persons Omaha and Sioux City had just crapped in!

But I guess I just cant imagine that automobile exhaust pollution blowing out of the Kansas City area is pooling around somebody else's home in Chicago, St.Louis or Memphis. The Midwest is a BIG place! - And I don't drive my car very often either. Should I put fuel injection and cat convertors on my 1962 Dodge?

Hey, plums, I'm not saying your wrong, I suppose, to me, its a matter of numbers and geography - If I lived in LA or Denver, I'd never consider gutting my cats. And Hey! At least there's not lead particles from TEL drifting in and out of all our lungs anymore.

bfsgross, You are right, the cars I have gutted the cats on (sorry Plums) HAVE ended up sounding a bit raspy.... My son's Mazda RX-7 sounds kinda cool but a rasp is definitely a component of that sound - I had thought it was the innate sound of the rotary motor. I used to have a '79 Z-28 that had gutted convertors and when it was revved, it too had a bit of a "rasp" to it. Perhaps this is NOT the deal for my XKR.

Hmmm Reconsidering now....

Thanks for the input guys,

 

Went to Meineke last week, removed the center resonator and left the rest intact. Not much difference in the sound. Then removed the next 2 mufflers leaving the rears. Sounded a little better. Went ahead and removed the rear two. Now it sounds like a tuner care, braaap. What can I do to get a better v8 sound??????????. Has an H pipe where the center resonator was removed.

 

Not a good idea to split the systems, it unbalances the engine and loses low down power....

I have removed the cat innards when they have broken up by themselves just to stop the rattle until new ones are obtained, problem you get is too much flow also reduces low end power and a benefit is not felt until you hit over 3000 rpm at which point because of the auto box you are already doing 100mph+ unless you use the J gate but nobody drives like that all the time (unless you are maxwdg), I will always recommend an X pipe of some description

 

Go back and re-read my post. XKRacer makes perfect sense with loss of balance and backpressure. Simply maintain original cats or place on sport cats, use the Borla or Magnaflow center mufflers with built-in x-pipe while maintaining resonators and rear boxes. If need more sound, then delete resonators, see how you like it. Drive uphill in high gear betweent 2000-3000 rpm to detect drone. If no drone and more sound is required, then swap in a pair of rear boxes such as Borla's, Magnaflow's, etc. For many, just placing in 200 cell sport cats should do the trick while maintaining the stock exhaust.

 

Well, I had no idea what the exhaust system was supposed to look like when I bought my 2002 XK8. But after I got it home and on the lift I realized that something was not stock. After referring to the Jag manual I realized that someone had removed the middle mufflers and added a crossover pipe. The job they did looks kind of rough, but the sound is very smooth. At speed, especially with the top up, it is very quiet inside. But when you have the top down and push it a bit it sounds very good. Maybe not as good as my hot rods, but just about right for a "sexy cat".

 

Dang! Larry, you have a nice collection of old toys.

 

I use the manual side of my J-Gate 90% of the time, seriously.

God, I long for a manual trans. I like to shift when I feel like it - not having the 'Ghost in the Machine' do it for me.

Control freak?

Possibly....

 

Edited accordingly

 

Max, your wife is well blessed...thus so are you.