I have read a lot of threads about attempts to improve the sound of the vehicles exhaust. Rear muffler delete, center delete, x-pipe, h-pipe, remove everything from cats back- except rear mufflers, Mina, Borla, Adamesh, etc.

I am wondering if anyone ever just tried replacing the rear mufflers only? Any success/satisfaction? Any reason that would be a bad idea?

Thanks, Jac

 

The lowest cost option to improve sound is the rear muffler delete, Adamesh Europe and Mina Gallery sell them (Mina's is a little better, Mandrel bent, I bought both). The tips actually look rather good too. I likely spent $5K messing with this and the best sound I got for the money was the first thing I tried and that was this. Did it to an XK8 (Adamesh) and an XKR (Mina).

 

Rear muffler delete helps a bit... replacing the factory over axle portion helps too I'm sure. Replacing the center muffler with a Borla really opened the sound up for me, but the best change was replacing the cats.

Yeah, replacing the rear with a Mina kit was nice. It wasn't enough for me. I have NP cats, h-pipe right up front leading to the Borla 2x2 with straight pipes to the Mina cans.

I can rev up in front of anything... Ferraris, McLarens... not that I could ever beat them, but I can sure as hell sound as nice as one. One of the best and most unique exhaust sounds that my muffler guys or I've ever heard. I didn't do it all at one time so a bit of it is a little more patchwork than I'd like, but it sounds so good I don't want to mess with it.

I'm sure anyone who has done a full performance cat - back system will attest to how nice this supercharged engine sounds with a clear throat...

 

I think Jacsun is more on the idea of replacing the muffler with another type rather than doing the delete as he already mentions it? I could be wrong but that is the impression I got.

You can remove the rear box completely and you would hardly notice a difference in sound, with the straight pipe added all you are doing is adding a trumpet e.g. Purse your lips and blow, just air comes out, stick a musical instrument to it and do the same thing like a trumpet and you will wake the neighbors and the dog down the road, so you get my drift....
The rear box is a straight through resonator box, its purpose is to do exactly what it is called and stop droning, this is why with the muffler delete setup you get frequency noise at certain speeds around 40-50ish mph after that and before is fine..... OK after that lengthy explanation, yes you may get more noise but not much as you have a box in the way, unless you fit a cherry bomb which after all is a musical instrument for your exhaust

 

I had a factory exhaust. Had the rear most boxes replaced with pipes, sounded like a muscle car with deep V8 tone. I loved the sound, but it was loud, very loud. I was surprised it made such a difference. The real problem was the drone though, at about 2000-2800 rpm it became maddening quickly. Went back and they installed magnaflow glass packs, now too quiet. Not like factory, but that V8 rumble was gone. Went back again and removed front center muffler, installed x pipe. This woke it up, sounds about right mostly, very little drone, has a nice tone, but still not quite enough low rumble - still not completely satisfied now. I really don't understand the whole thing...mid to late 60's and early 70's muscle cars had simple exhausts with a pipe on each side, maybe an H pipe crossover to balance, and a muffler on each side, nice sound, no drone. Why can't we duplicate this at a good/reasonable price. I can't believe the cats are a factor except for reducing some of the overall volume, but are they the drone source? I would think not. Shouldn't it be as simple as those muscle car systems?

 

I replaced my rears with simple pipes and tips. It improves the sound, especially with the windows down. However, not nearly as loud as all the V8 powered trucks I hear constantly. I also don't drive on the highway much and the drone is amusing to me.

I drove 2 days with absolutely no pipes, and while very fun, it was awful on the highway and massive reduction in back pressure reduced low-end torque.

I'm planning to eliminate the middle cans completely in 30 days or so after I pay for lots of maintenance in 5 days.

 

Thanks everyone. XKR had it right and these responses explain why I havent heard of anyone just replacing the rear mufflers-only.

 

I actually systematically replaced every one of the components of the exhaust. The biggest single change by far was going to the Nameless Cats, the stock cats make a huge difference in sound volume. I even had electric cut outs for a while (fun but scary loud). I ended up with the MacLeod system, not cheap but a nice sound. Only issue is that on a lowered car the second set of mufflers (needed for the Nameless cats) are about .5" too low. I'm going to try it without them later in the year.



Were I to do it over again I'd likely start with the cats and not end with them as I did. They give both a performance and a sound boost.

 

Has anyone tried deleting the center muffler or the before-the-axle mufflers? Or perhaps replacing either of those with a freer flowing muffler or glass pack?

It sounds as if the rear mufflers are more like resonators intended to reduce droning tones than to quiet the exhaust note (though anything will reduce the sound somewhat.)

The consensus seems to be that the best option is replacing the catalysts but I'm hoping to find a lower cost and less involved option.

To be clear, I'n more concerned with getting a nicer (louder) exhaust tone than looking for performance gains.

 

Someone here removed the center muffler and the two little ones completely and put in some Magnaflows on the rear with great effect. He then put a central X Pipe which many of us thought diminished the v8 sound too much but it made his wife happier.

I will try straight pipes for a week, and either live with it or go with glasspacks in the center. Being a coupe, you cannot enjoy the sound out back anything close to convertibles. As a result, glass packs in the center for coupes looks good, and someone else did that and was quite pleased. Glass packs wear out so I am told to plan to replace them evey 3,000 miles.

 

You'll get drone removing the center muffler... not so much on an xk8, but a bunch on the xkr. I've done it to both. The xk8 sounds ok without a center muffler... it sounds horrible on an xkr. I ended up putting a Borla 2x2 in there and couldn't be happier.


The oem cats are the primary source of sound reduction in the factory exhaust. Replacing them gives a boost in sound level and an incredibly nicer exhaust tone.

They also add a nice performance boost... of course there's debate about the results but dynos have showed as much as 17rwhp, but somewhere between 8-10 is typical. At least from the few reports that have popped up here that I've read.

 

I removed the front muffler and substituted an "H" pipe. I couldn't tell much of a difference from that. I removed the two rear mufflers, and they ARE mufflers, and substituted a pair of "Turbo Tubes" and welded on Monza twin outlets. Now it sounds pretty good, a bit of rumble at idle and almost quiet cruising. They have a decent roar when accelerating hard. There is a slight drone around 2000-2500rpm though but I have to pay attention to notice.

 

Where did u get the "turbo tubes"

 

Summit Racing, Talmadge, OH, get the shortest ones, I think they're 18". They're online.

 

If you just removed the center muffler and put the H there and then replaced the rear-most boxes, do you still have a box on each side between your turbo tubes and the the H-pipe or is it just exhaust pipe between your turbo tubes and the "H"? Thanks!

Also, regarding the turbo tubes, I see you recommended the 18" ones. Is that just so they fit or do they sound better than the longer ones or something else??

 

Mike,

You have heard mine. I have a very short "H" crossover (virtuually an "X") with 2 center glasspacks and straight pipes out the rear with 4" tips. I would go with Rob's recommendation to eliminate the rear muffler. Any custom exhaust shop can do it for less than $200 including the tips of your choice.

Dave

 

Yes, the little square resonators are still there. I went with 18" because of space up under the rear fender. Doing it again, I'd probably just go with straight pipes in back and a pair of turbo mufflers up front. I may do that anyway, I've been known to "improve" things until they fail.

 

The biggest problem with any aftermarket exhaust or OEM delete is exhaust drone. Drone is not heard on a typical U-Tube exterior sound test. It is heard loud and clear in the cabin around 1300-1500 rpm. It is a huge problem for any daily driver. Drone is not a problem autocrossing or tracking as most of the drives there are well above 1500 rpm.
All manufacturers spend a lot of R&D eliminating drone; and Jaguar has done so by an active exhaust, which opens up under full throttle, etc. Corvette has also addressed drone with an active exhaust at $1100 extra.
You can spend a lot of money for a shiny "designer" exhaust, which offer little technology betterment than comparatively cheap off-the-shelf components.
First check the central resonator which, I believe, covers an "H" connector between the right and left exhaust banks. Consider an "X" pipe. Not sure, but think the latest and greates XKR-Rs are using an "X" pipe. Whatever, you can buy just an X pipe cheap from Magnaflow. Or, you can pay a little more and buy Magnaflow's own resonator with a "X" connector inside. My research indicates that a X pipe connector reduces some of the exhaust "crackle" to a more mellow tone.
For the rear mufflers check out the Dynomax VT muffler. These mufflers have a spring loaded interior flap, which opens on full throttle - much like the OEM mufflers on the base 2007+ XK. The Dynomax VTs "work" as advertised. I had them on another car for well over 30K miles with no problems whatsoever.

 

please delete incomplete entry

 

Thank you! That is great news.
Update, rear muffler delete is a drone monster for hour long canyon runs so everyone else is correct. Did not bother gal in the passenger seat but certainly did not add proper V8 sounds when blasting it.

Straight pipes next, then electric cut outs. If still not good enough then Dynomax it shall be