Cat or No Cat or High Flow cat??

BlkB14 · 09-24-2002, 02:38 PM

Which should i go with?
I'm not too worried about not having a cat, cause no emissions testing where i live.

98SERwTricks · 09-24-2002, 02:43 PM

Run a cat. The stock cat is more than enough flow-wise unless you are running a turbo. Give a sh*t about mother nature... Please...

SmoothDaddyFig · 09-24-2002, 04:08 PM

I use a fast flow Cat but I have no EGR.

Go figure.
But I would say go with a fast flow Cat.

I want to do a 14.1 all motor!!! GRRRR!!!!

CowboyDren · 10-01-2002, 03:13 AM

Stock Nissan cats are high-flow cats, with 2.5" inlets and outlets, no less. Unless yours is cracked or clogged, leave it alone. Removing the cat on N/A SR20DEs has actually shown HP losses, and a Random cat showed no gains. Again, if it ain't broke...

aztecred92 · 10-01-2002, 02:13 PM

Quote:

Originally posted by 98SERwTricks
Run a cat. The stock cat is more than enough flow-wise unless you are running a turbo. Give a sh*t about mother nature... Please...

Ditto.

ALLMOTORSENTRA · 10-01-2002, 06:26 PM

Im runnin no cat

SE-Rican · 10-01-2002, 06:28 PM

Quote:

Originally posted by ALLMOTORSENTRA
Im runnin no cat

I also am not running a cat. My car runs awesome. It is louder than a mofo but I deal with it. When I dynoed the 157.5hp I did not have a cat.

Rob · 10-01-2002, 10:26 PM

Quote:

Originally posted by SE-Rican
I also am not running a cat. My car runs awesome. It is louder than a mofo but I deal with it. When I dynoed the 157.5hp I did not have a cat.

mother nature hater!!

I had no cat on my car for a while, i couldnt take the noise, that sh*t was LOUD! I can tell you that test pipe vs. cat, a test pipe wins. I know, my buddy and i raced on the um, well dont worry, but 1st thru 3rd neck and neck, in 4th i would walk away by a car. so, on an track, its worth it, daily driving i dont think so. I run a random tech cat now, car is nice and quiet with a crush bent 2.25" and borla muffler

coach · 10-02-2002, 01:00 PM

I had an incident with a log and an on-ramp that ended in my exhaust layin on the road. I went to a shop and they welded a mandrel system in with no cat, now, I run WITH a cat and instead of a 40 series flowmaster I have the dynamax ultraflow, and it is much much better. Stick with the stock cat if it is ok, if not then get a universal high flow catco catalytic convertor and have flanges welded to it and install that. Not much backpressure at all and it sounds much better and is better for the environment.

Brent Meints (not a tree hugger)

chriscar · 10-02-2002, 01:09 PM

I can tell you guys the without question, a stock cat will not hurt power on a bolt-on car. I was at the Boston dyno day and ran with and without the cat and there was absolutely ZERO difference, other than the standard variation from run to run.

My mods:
Older HS header, probably 2nd or 3rd gen
UR 2 pulleys
HS CAI
Mandrel 2 1/2 exhaust
Dynomax 2 1/2 UltraFlow Bullet as a resonator
Dynomax 2 1/2 UltraFlow muffler

With the cat in I get some rice boy buzz between about 3 & 4,000 rpm, depending on how hard I'm accelerating. Without the cat the car sounds like a dozen angry Vtec's.

It's so loud and buzzy that I felt like a criminal when I was driving it, and I know the neighborhood probably wasn't too happy with me driving through at 5am on my way to work.

P.S.
This is with an original 106,000 mile cat.

eliterit · 12-31-2002, 01:30 AM

question.

if i have a cat with 160,000 miles on it, is it time for me to replace it? How long do they usually last?

Teal97 · 12-31-2002, 07:28 PM

my cat is original @ 149k miles. i don't think it hurt my last dyno #'s.

mapball · 01-05-2003, 04:32 PM

i easily passed emissions here in seattle on my 97 se-r with gutted stock cat.