Catalytic Converters and performance

[Jeff]

I have been doing a lot of asking and soul searching on this topic in the past two days. The van is far too loud now and something needs to be done. Rex tells me that catalytic converters do not hurt performance. What can MM tell me? Are some better then others? Is the $50 e-bay special good enough to get me by? I'll miss the sweet jet-engine sounds of the turbocharger.

[Jeff]

Also, is a shorter cat better for flow? How about the shape? (Bullet or traditional)

[Mike]

a resonator will cost less, reduce more noise, and i would guess do the same to exhaust flow...

[NTIman]

A properly operating Catalytic converter will most likely not hamper performance enough to take one off of a street car.

That being said, since you don't have one at all, unless you're worried about passing inspection (which I think you have that covered pretty well) I'd go with a resonator, cats are kind of expensive to use if you're only worried about shutting your car up a little bit.

[Jeff]

4in around glasspack, 2.5in in/out
Summit?
Thrush?
Dynomax?
Moroso?
Magnaflow?


They range from $21 to $60 at summit racing. Should I go with a "glasspack" like these or a round muffler? Glasspack is going to give me the maximum flow, has anyone heard anything about one brand hushing sound better?

[WRXtranceformed]

A high flow cat will give you about the same hp numbers on the dyno, but you'll sacrifice a tiny amount of spool. That's what I remember from my Suby days anyway. I agree with the resonator, or just get a more muted catback. Magnaflows sound awesome, they're deep and mean but aren't too crazy loud.

[Jeff]

Resonator = glasspack or no?

[WRXtranceformed]

Um I dunno. I think a resonator goes before the muffler? I thought glasspacks usually made your car louder?

[Mike]

resonator = resonator.

a dynomax or magnaflow oval muffler will be quiet as a mofo (what i have on the civic). couple that with an 18" resonator from either of the two and you're money.

[HAULN-SS]

I have dynomax ultra-flo's and they're not that loud for a glasspack, although I have a X-pipe setup too, so that's turning it down somewhat

[PDenbigh]

Don't put glasspacks on a 4-banger. I have just a resonator on my side exhaust 2.3 turbo and I personally thing it sounds pretty mean (as opposed to bumble-bee-like).

[Jeff]

Alright, so muffler != resonator. What exactly is a resonator designed to do? Are most of them strait though type for getting rid of harshness?

[HAULN-SS]

I *think* the resonator is more for sending the 'drone' out the tailpipe instaed of into the cabin..no?

[Mike]

I *think* the resonator is more for sending the 'drone' out the tailpipe instaed of into the cabin..no?

no.

[Mike]

Alright, so muffler != resonator. What exactly is a resonator designed to do? Are most of them strait though type for getting rid of harshness?

yes. they trap high frequency shit.

[Jeff]

ok, I am having a hard time finding anything online termed "resonator." Like I said magnaflow has a "muffler" that I think will serve my purpose.

[Mike]

<!-- m --><a class="postlink" href="http://sms-products.com/Exhausts.html">http://sms-products.com/Exhausts.html</a><!-- m -->

[PDenbigh]

Resonators:

<!-- m --><a class="postlink" href="http://store.summitracing.com/egnsearch.asp?N=700+4294923429+4294922711+115+4294804382">http://store.summitracing.com/egnsearch ... 4294804382</a><!-- m -->

It does appear that there is a fine line between everything. This is what I have on the XR: <!-- m --><a class="postlink" href="http://store.summitracing.com/partdetail.asp?autofilter=1&part=WLK%2D24215&N=700+%2D43867+%2D44585+115&autoview=sku">http://store.summitracing.com/partdetai ... toview=sku</a><!-- m --> except I have the 3" version.

[Jeff]

Pete...that is a glasspack as far as I know. When you search "glasspack" it comes up in the list. As for mike...the freakin magnaflow I am looking at is on that page listed as a resonator. Magna calls it a muffler. I think its really a potAto-potato kinda situation.

[PDenbigh]

A true glass pack is a cylindrical muffler like that, but it actually has a fiberGLASS-like material as an insulator so that it provides that "crack" sound. That link I sent you is not a glass pack. I imagine that list it under there because "glasspack" has become a generic term like "xerox."