carsound cat... size? - Honda Prelude Forum

munscher · 06-13-2004, 09:59 PM

I've decided to go with a carsound hi-flow cat but am unsure of which size.

What size is the collector on the DC cc header? 2.25"?

I also have an old school RS*R exhaust which i believe is 60mm, so am i better off with a 2.25" cat or the 2.5" cat. If im right about the size of the DC, then i assume its better to keep it 2.25" and then open up into the exhaust t han to go too large and create turbulence.

Also, how many people with carsound cats have had them break down and rattle? how long did it take?

caLiH22a · 06-14-2004, 12:02 AM

I would say, modify the collector on your DC header to 2.5", get a Carsound 2.5" exhaust and get your exhasust pipping 2.5" and it will flow real nice. I have a 2.5" exhaust with a 2.5" Carsound cat and it flows real nice, mine hasn't broken down or anything so it's still good but I don't drive my car much, mainly on the weekends and track events.

ancient · 06-14-2004, 12:45 AM

just get whatever fits, the difference between 2.5 and 2.25 is minimal.

branko · 06-14-2004, 06:36 AM

Actually difference is quite large:

2.25" cross section area = 3.9740625
2.5" cross section area = 4.90625

So small 0.25" diameter increase (11%) increases flow area by 24%

Anyway, I got myself a 94105 cat, have a JDM downpipe with 60mm collector and modifed the piping from flex pipe (just before it went down to 2") with some 2.25" piping going to 2.25" cat - so it flows nicely now

munscher · 06-14-2004, 09:30 PM

so can anybody confirm that the DC downpipe is 2.25"?? I'd rather not go remove mine to find out and i can't find the info anywhere including DC's site.

yohan420 · 06-15-2004, 04:14 PM

anything wrong with usin ga 2.5" universal carsounda nd putting 2.25" piping/flanges on it to bolt up w/ stock header & greddy sp cat-back ?

(When I do an engine swap I'll get a diff header as well..)

branko · 06-15-2004, 05:40 PM

Nope its like 2" or 1.8" ID or something. You should modify your collector to 2.25"

Quote:

Originally posted by munscher
so can anybody confirm that the DC downpipe is 2.25"?? I'd rather not go remove mine to find out and i can't find the info anywhere including DC's site.