After my experience with my 4.2 XKR (now have 5.0 XKR), and from what I've read on this forum for years now, I've decided to leave my exhaust stock, other than swapping over to FrickenFast 200 cell downpipes. This is due to not liking the sound of the X-pipe, not wanting to introduce ANY unwanted drone (can't handle any of it), and not wanting to hack up the stock exhaust. As heavy and unattractive as the stock muffler is, I like the active exhaust feature, and don't see any need to spend huge money on one of the aftermarket options, for what little they offer. 200 cell cats on the stock exhaust sound fantastic with the valve open, and 100% tame whilst cruising with it closed. Best of both worlds. Do I care about the extra 1-3 horsepower from the X-pipe and shaving a few pounds be deleting the resonators? God no. Not worth the time, money, and potential devaluation when I go to sell the car in 2-3 years. Anyway, just my .02 for those of you on the fence. In a nutshell from someone who has done all of these things....leave it alone and just add 200 cell cats (preferably from my good buddy, FrickenFast ).

 

Isn't swapping to the 200-cell cats considered "hacking up the stock exhaust"? Replacing the resonators with an X-pipe is a direct bolt-on, and easily returned to stock as long as you don't throw away the one piece. There IS no drone with removing the resonators and the X-pipe add.

 

No, as the FrickenFast unit is bolt on.

The X-pipe is a bolt-on if you go with an expensive aftermarket unit, correct, but I can't justify that cost.

Correct, there is no drone with res delete and X, but I don't like the sound of that setup.

 

Are those Cats monitored or just passive?

 

If you're going to sell the car in 2-3 years then why waste your money installing new cats.

 

I just commented on the XE forum that when I did the resonator delete and X pipe in my (2010) XKR it made the car more howly than growly, i.e. it lost the throbbiness of the stock exhaust.

That said, it sounded wicked when I gave it the beans.

 

You also said

This is one thing I can't stop playing with on my recently acquired '10 XKR. I don't know how loud it is outside the car but from the drivers seat, with the windows open, the 'grumbling' is so deep. Does the X pipe increase the volume/frequency of them but change the note or are they still very deep?

 

From memory it loses some bass but it sounds pretty good, like it's muttering under its breath.

This video is of an XFRS but it is very close to how the XKR sounds with the X pipe. And before anyone gets all strident about it (as happened a few years back when I put it up), I dont endorse the driving, but the sound is wicked

 

What happens with the X pipe, is it allows peaks in pressure to travel across the opposite pipe. This mutes the loudest portion of sound blasts. It also takes away some of the cross plain crankshaft V8 "rumble", as when two cylinders fire on the same side they aren't fixed on staying in the same pipe together, while the other pipe goes empty.

 

Yep, X pipe mutes the rumble.

 

because they sound amazing, will add HP when I do the tune and pulley, and just like I did on my 4.2, I sold them after and made much of the $ back. plus, 2-3 years is a long time in my book when you really enjoy something.

 

2-3 years is a long time in my book when you really enjoy something.[/QUOTE]

Sorry but gotta laugh here. 2-3 years is a mere snapshot. I usually have a min of 10 years . Last car I had for 14 years.

 

Sorry but gotta laugh here. 2-3 years is a mere snapshot. I usually have a min of 10 years . Last car I had for 14 years.[/QUOTE]

didn't say it was a long time to own a car. I said it was a log time (in my opinion) to have a part on your car that you truly enjoy and can sell after.

as far as length of overall ownership (unrelated to parts), I get bored with cars quite quickly and like a change in 2-3 years. plus, i want an XKRS next.