danglerb

All new cats stink, but that should be gone in a few days.

What stinks forever is running a car without cats for no real gain and polluting the air.

Its a bit of a sore point with me, every time I hear about people running without cats it makes me want to vote for nationwide smog testing.

Cliff Ruckstuhl

If the cats removed makes no difference then I will keep them in place I had just thought it would be a gain for a car I will drive less then 3000k a year.

Keeping it Green

Cliff

danglerb

The old cats might be eating some HP, its the new OBDII style that really flow. The new spun metal cats from Magnaflow look really appealing to me, the 59950 series I think.

Once you recognize the smell of a no cat car, many start to notice it.

auzivision

I currently have a stock exhaust except for the RMB. I love the current sound and really want the performance gains the x pipes offer, but I don’t necessarily want a screamer (exhaust system that is…)

I could live with a little more WOT sound, but don’t want to rattle the windows in the neighborhood at low RPM or have every slight throttle change be noticed by my wife when freeway cruising at 2200 RPM.

I have an older S4 with the larger resonators and am considering an x-pipe with or without high-flow cats and wonder if the cats offer up much in the sound deadening department. The other choice would be to x pipe with no cats and put a rear muffler back on.

I really like the look of the dual black pipes out back and don’t want to go back to one. I guess my choices are:

A) X pipe, no cats, S4 resonator, RMB
B) X pipe, high-flow cats, S4 resonator, RMB
C) X pipe, no cats, S4 resonator, S4 Rear muffler

While I leaning towards A or B… is there any other options I should be considering?

Also, I cant find much on the comparisons between the ones supplied from Utah (?Motorsports?) versus the ones supplied from North Carolina (928 Specialists). Anyone care to share their opinions between the stainless steel versus matrix metal.

Are they both modular (as in easy add or delete cats)? Are they both available (as in with in the next month or two)? I believe they both offer dual O2 sensor connections. What other aspects should be considered?

Cliff Ruckstuhl

928 Motor Sports have a good deal going on the X pipe set up. I am going to look into the X pipe set up next week.
Cliff

the flyin' scotsman

My X, GT resonators & RMB combo was loud enough to set off car alarms; one particular instance when parked on a city street the car parked behind alarm was set off when I started the 928; oops.

With the larger 'S4' resonators you may be ok with option A, just keep the original muffler around if its too loud.

Understand what your saying re. the twin outlets, thats why I ended up getting the GT rear muffler.

The Motosport X (designed, developed and manufactured in Utah) is sold through 928 Motosport...........check out their site http://www.928motorsports.com/ so you can compare the 2.

Cliff Ruckstuhl

How do I get my car to sound like the car on 928 Motorsports when you open ther web site up? That is very nice.

Cliff

H2

I find this discussion useful. At some point, I'll be installing a "cat back" RMB or Xpipe of some kind on my '88 S4. I've really not studied the options yet since I have other changes I want to make first. On my '85S I kept the cats and added a dual pipe RMB with two small glasspacks. It's a bit too loud for radio listening, etc but I like the sound although admittedly too loud. I haven't checked to see what's available in cat-back X pipes with some kind of small muffling...slightly softer sound than on my '85. I'll probably go with an X pipe but need to make some comparisons. I hope this discussion continues. Thanks.

HH

HH

danglerb

Somebody needs to start making some sound clips. Maybe the next gathering record the classic exhaust parade where one at a time cars startup and then tear off down a street, with a text description of what each system is.

BTW nothing prevents you from having two pipes out the back regardless of what goes before it.

Ketchmi

The 100cpi cats I had made lose almost no horsepower but do deaden the sound quite a bit. With 87' resonators, high flow cats and an RMB you will have a great sound. It's only slightly louder than stock with an RMB but flows considerably better. If you re-install the rear muffler, it will be almost as quiet as stock. With no cats and the RMB, it may be a touch loud but at that point is personal taste. It's not obnoxiously loud but you may have to pedal it a bit when driving past folks that don't appreciate it. I have ran that way for years and most people have good comments about it.

The new Magnaflow 59956 is about the same as the 300cpi ones I tested and until recently sold with the X. It will lose approx. 7 horsepower on my setup. The ceramic substrate 400cpi's made by car-sound, magnaflow, gorlich and others lost approx. 14 horsepower.

I also now have some small mufflers that go in place of the cats. I haven't had a chance to test them yet but will soon. I had them made just for the folks with GT style resonators and an RMB that don't want cats. I believe they'll take the edge off of the sound. I had our GT running an X, no cats and with the small resonators and an RMB for a while, it did sound quite exotic but I was scared of breaking store windows if I really opened it up in town.

Stainless steel vs. matrix metal? All cats are constructed from stainless steel as far as I know, are you talking about the X itself? We now offer stainless steel X's for $549.95 and yes, they are all modular in design allowing you to switch between cats, mufflers and straight pipes in about 15 minutes.