+1 on that although on occasion I have to walk away from an issue to sit and think.

Had to do that when our vacation home had frozen pipes in MA after a power failure a month ago. Many,many breaks but no flood as water was off.

 

I doubt you will hear much of a difference between the two, however you would hear more of a difference between 200 & 400. There are other factors in the exhaust that will also affect tone/note for you to consider. I went with 200 cell cats, removed the resonators for an x-pipe & plan at some point to fabricate a custom rear box.

No offense but I think you are WAY overthinking these two options considering how little difference there is between them and should just pick one of them on your own. But if you are really that particular and can afford it, I can certainly understand, then you should absolutely just buy both and figure it out on your own as you are the only one who will appreciate the difference.

 

jahummer,
What brand of 200 cell cats do you have? Did you have any issues with C.E.L.'s? Also, I see your build is probably meant more for the track/strip, I'm just a daily driver...in your own opinion, do you think 200 cell is too obnoxious for the street?

 

Magnaflow, but I custom fabricated the full assemblies and kept the original cats. No CEL issues. Over time the tone of the exhaust will change with use. It is loud but not obnoxiously loud however it is no longer a quiet car by any means, new cats and possibly tune also caused over run loss. Just removing the resonators made it louder than stock as well.

 

200 cel cats are great however codes are more probable than not….even with oxy extensions. Most tuners can eliminate the codes easily. Reading your mod list i think you need to look at pipe diameter as stock mods on 2 1/8” 2 1.4 “ piping is not efficient scavenging for any v8 over 450HP regardless of cats, mufflers or x pipe. If you want performance results along with sound you may want to look at 2 1/2” to 3” from cats to tail pipes more so if you like deep tone as you mentioned. X pipe is also very effective at stopping pops and crackles. 2 1/2” pipes 100 to 400 cel cats high flow mufflers, resonators or not, gives more of an Aston 4.7 v8 deep rumble roar plus the scavenging necessary for high horsepower engines .




my2c

 

You just created a monster.
People will say "You NEED back pressure!".
Well, to be honest, the current TUNE needs back pressure, not the engine. A hoover industrial vacuum on every exhaust port would be very useful for building power. Back pressure keeps dirty, nasty, unburnable gasses inside the combustion chamber. What good would that do? It would create a lower fuel demand to keep the Air/Fuel ratio correct, and less fuel equals less power.
You are right about larger exhaust, but ONLY if the TUNE is changed to compensate for vastly improved exhaust flow. It's very problematic to get a proper CUSTOM tune on these things, very near impossible for most of us.

 

EGR lowers cyl temperatures, too.

 

On my 2007 XKR I gutted the cats (took out the bricks) welded in a 2" perforated steel tube and then packed them with ceramic glass. Welded them back up. Basically made up a set of mini glass pacs. Only other modification was pull fuse 19.
The good; exhaust note was beyond amazing. Almost-ish normal under most situations but with a deeper growl. But when on the fun pedal everyone around you knows something is going on. Zero drone.
The bad; no back pressure which resulted in a loss of power. Not really an issue unless you participate in the red light grand prix on occasion. CEL all day long. Will never pass a MOT. Non-existent in Wisconsin.

I had Alpha Jag load up a tune which also eliminated my CEL. This did change the exhaust note back to a little more mainstream by tuning for the increased flow. The increased power is too much fun. Traction is now an issue, never was before! But it still is way beyond better than stock. If your car has to pass an emissions test this would not be the way to go.