Has anyone out there have first hand experience with the difference in sound between the 3 different cell counts .

I'm currently running 100s vs x pipe

 

I think it is well known that lesser cell count = more noise. But wonder about power?
Anyone doing before/after dyno testing?

 

What I'm trying to determine is how much quieter the 200s and 400s are as I'm contemplating switching over to them from 100s

Power wise I'll be posting up official 1/4 mile times this week with 'old jaguar' tune and x-pipe . Expecting to see mid to upper 13s this time around

 

I think you'd need a decibel meter and an honest cell count to know what data you were collecting. In the other thread it was mentioned that the Magnaflow's I have are probably 200 cell but an eyeball count suggests they're a lot closer to 300 or even 400 cells. Actually after looking at mine a little more I think the definition is cells per square inch, not per core. Using a ball point pen for reference my Magnaflow cells are @ .100" which is 1/10th of an inch so 10x10=100 cells per square inch. That seems a really dumb way to measure then as the more core area, the more flow you'll get. Add in the metallic has thinner walls and you get more flow per square inch.

Grrr. So extend the math a bit. My shell is 4" diameter, say the core is 3.75". So, 3.75/2=1.875x1.875=3.52x3.14=11 square inches of core x 100 CPS = 1100 cells across the core.

Back to the point, the stock 2011 5.0 Mustang cats I installed had a tighter cell count, but not a huge difference, say 150 CPS but the core is also much larger vs. the Mags, maybe 4x5" but had double the length. I think the 2nd core is what actually quiets the exhaust. Mine went down @ 1/2 in amplitude (3db) when installing the larger / longer stang cats.

If the original Jag cats were true 400 cell cats I can understand why they clogged up and failed. Truth be told, we really don't know what we have.

 

The factory cats are a pair of bricks, 600 cell in front, 400 cell behind, this is described in several of the technical guides.

That's a lot of cat, and therefore no surprise that the stock cats on their own have quite a muffling effect, and when you remove them (or go to a 100 cell, 200 cell, etc) the cars get really loud.

This was the problem I had with my XJR, I did not know that the factory cats were choked up, and I had the exhaust modified as it was "really quiet" and then after putting on the 100 cell cats, man it was just too damn loud...

I have a source for 400 cell cats here in Sydney, and although they could not give me any precise noise numbers, it was mentioned that "400 cells aren't as loud as 100 cells" which makes sense, but how much quieter 400 cells are than 100's, guess we won't know until we try it.

I'm positive that the cats in my XKR are choked up, the car is not loud at all, even with fuse 19 out, my XJR with 100 cells and straight through rear mufflers (stock center section) is way louder, and not in a nice way...

I'll have the 400 cells fitted soon-ish, I was planning on having the XKR-S centre pipe replicated as well, with the straight pipes and x-pipe in there. Maybe i'll get a chance to try both combinations; with/without cats, with/without XKR-S style center section.

 

What about the primary function? You know, emissions? Some of us live in an area where they are tested.

 

The 100 cell ones in mine pass the smell test easily.

 

How many miles on them?

 

Cambo - have you ever thought about taking the 100 cell cats from the XJ and putting them on the XK and then putting the 400 cell cats on the XJ?

 

Not many lol. I took them off because they were just too rambunctious and loud. From what I've read, 3 years more or less of constant driving before they fall apart. That's not a horrible ROI for me to keep clean air. On my '93 Mustang I'd just get a $400 waiver receipt from a friendly shop and game the system. I get four years of use (two emissions inspections) before needing to replace them. Heck, I could still plug the after o2's bungs and let them breath atmosphere and still pass the OBDii tests we have now.

 

Only took me 5years but I finally made the shift to the 400cell cats , no more ugly raspiness the vehicle sounds devine a very rich & athletic sporty sound ... 400s definitely the sweet spot ...superb

Funny enough I measured the dB and the same reading as 100cell however a much richer refined sound

 

Bet the neighbors are happier now too!

 

Haha very true !!!
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