I bought a 2013 XKR-S with straight pipes beyond the X-pipe. Sounds awesome, but way too loud. A stock exhaust, or any of the better aftermarket systems, are more than what I want to spend at this time.

There are a ton of Magnaflow options with 2.25" inlets, either straight through or XL series with baffles. Also 3.5 x 7" or 4 x 9" ovals in 14" or 18" lengths. Single inlet and either single or dual outlet.

Another option could be a single straight through 4 x 9" muffler with dual inlet and outlet, either longitudinal (parallel) or transverse (crossover).

I'm looking for a nice, deep sound with some bark and over-run pop, but reasonable volume at higher revs and near WOT. I need to stay somewhat stealthy when I'm flogging it in the canyons and one of my local tracks (PIR) has sound limits.

Anyone have part numbers or configurations that have either worked well, or not so well? I'm hoping to only do this once. Will post before and after videos for sound.

 

Here's the most applicable video I've found so far, this is with two 11148 mufflers, which are 3.5 x 7 x 14" straight through. I should probably go with something quieter than this.

 

Sounds good but quieter then my XKR when I'm in dynamic mode. I would think this would be good for cruising around.

 

Read my build thread. There's a ton of vibration and frequency dynamics you'll need to understand once you delve into aftermarket parts. With a straight muffler swap I'd expect some unpleasant drone during cruise.

That Mag video doesn't represent how you are droning along on the interstate.

 

the drone will be miserable without the stock muffler or some expensive no-drone corsas. I know this from experience.

 

Still looking at options, also considering Borla. Corsa doesn't sell individual mufflers or have systems for our cars. I'm working my way through Ranchero50's thread, very impressive fabrication work!

Here's a startup video from my phone, with no mufflers. I rev it to 2k a couple of times, and you can see the underside of the car.

 

i'm thinking that the magnaflow system is a great looker . bit raspy, although
seems inherent to the AJ-V8 a bit .

BUT also thinking a bout the poor shade tree bloke that has to change the diff oil in 10 years 5 owners time .

 

Here are some drive-by runs, without mufflers. I just have my phone stuck in a tree, so the sound isn't very good. I downshift to 2nd while entering the turn, both directions. I don't get on it very hard going downhill, right to left. Going uphill I can about floor it on the way out, and the DSC cuts the power as the back tires break loose (after I'm out of the frame). I haven't tried it with DSC in TRAC or OFF, the pavement was cold and there's obviously no shoulder or runoff on this road. Also, I typically would not cross the centerline, but I can see a long way past that turn as I approach it. I'm hoping to make it less raspy and quite a bit quieter, to attract less attention.

 

I think it sounds great, but yea, too loud for a car that will be driven often IMO.

 

I LIKE it!

 

Minor update: I've purchased two , which will be installed by my local guy tomorrow. These are 4 x 9" oval mufflers, 14" long. They're also available in 19" long, but I wasn't sure that would fit well under the existing heat shield. I love the noise with no mufflers, but it is excessive. I'm hoping this will be just enough quieter. If they're too quiet I might have cutouts added later. If too loud I could try another type or possibly add resonators between the x-pipe and rear axle.

Borla 40357

 

We cut out the straight pipes and installed the Borla 40357s today, re-using the existing tips. My local guy did a nice job, aligning everything perfectly. Using the offset-in, center-out mufflers, the exhaust is actually a straighter shot from the rear axle back than before. The car is dirty now, I've been driving in the rain and kicking up a lot of pine needles and junk from our forest service roads.





These are straight-through mufflers and I was concerned that they would still be too loud, but I was very surprised how much quieter the car is from inside. I'd say it's about 1/3 as loud inside on startup, and while driving you barely hear the exhaust over the tire noise, which is now much more obvious. Unfortunately, I did lose a lot of the pop and gurgle on overrun, but it's much less tiresome to drive around town or on the highway. With all of the discussion about drone, I was also concerned about this, but it's really undetectable. At low speeds on a slight hill at about 1,500 RPM there is a bit, but it was much, much worse before. If anything, the car seems to pull harder, but I suspect that I'm using more throttle and higher revs because I'm expecting more noise. Cost of the system was $188 for the two mufflers, $240 for installation.

Here's a new startup video from my garage, before and after filmed with the same phone, no audio adjustments. Drive-by video to follow.

 

Here's my before and after drive-by video, same phone and position in tree. I edited to alternate with and without mufflers on each pass. I was interested to hear that the car is not whole lot quieter when on the power going uphill, but it is when going downhill. It is much quieter inside the car at all times. I would have liked to have maintained a little more burble and pop, but I'm very pleased overall, especially for under $450. Success!

 

The funny thing is it doesn't really matter how it sounds outside the car as long as you enjoy it inside the car. Good deal that it's working well. Mine had drone problems around 2200 - 2400 rpm. Heavier load was worse.

 

like them both!!

 

At one time I was looking at replacing my muffler on my Ferrari 308. It required 2 inlets and 2 outlets in one muffler package. While doing my search I found that there were a few options with this configuration made for Camaro/Firebird cars. Also you may want to look at late model Mustangs which may have a similar set up. Something to look at as the after market folks make units for these cars.

 

Yes, looked at them briefly before smacking myself in the noggin as a reminder that I did not want my XKR sounding like a '80's Camaro.