High Flow Cats/Test Pipes...putting what with what exhaust

Well for those of you who have read threads started by me in the past, you will know that I have been on a long hunt for the elusive "perfect" exhaust for my car. This christmas, I will be installing an Apex'i N1 catback system for my 98 prelude SH, unless of course someone would like to let me know of an exhaust system that results in a larger gain in performance than the N1.

Now the real question: once the N1 is installed, I would also like to put either a high flow cat or a test pipe on my car in place of the stock cat. I am not familiar with any manufacterers who make high flow cats or test pipes, or whether certain combinations of exhuast systems and cats/pipes work better than others: quite frankly I dont know that much about them at all.

If anyone has any advice on a high flo cat or a testpipe i could couple with my exhuast, plz let me know.

Thanks! :evillol:

for high flow cats. the top name brands are carsound and random technologies. the random techs are nice but they're quite pricey. i would suggest getting a carsound. depending on your setup, you can either go 2.25" or 2.5". if n/a i would stick with just 2.25" but if boosted, i'd go 2.5" you'll probably have to take it to the muffler shop to get the flanges welded on if you get the universal cat. no big deal, $30 and it's done.

for testpipes, go to www.testpipe.com

So...you think I should go with the N1 then?

Will a carsould universal cat pass smog?

So...you think I should go with the N1 then?

Will a carsould universal cat pass smog?


what's your setup? the N1 does provide excellent flow, relative to most other exhausts. it is on the loud side however, and unless your boosted, it'll make little difference. so if you're not bothered with the loudness, go for it. it's an excellent system. there are others that are quieter, and IMO at least, sound better but also provide decent flow. for boosted applications, the N1 is easily one of the top choices. if you're not boosted, i'd also recomend the thermal or mugen(though pricey).

and yes, the carsound is 50 state legal.

what's your setup? the N1 does provide excellent flow, relative to most other exhausts. it is on the loud side however, and unless your boosted, it'll make little difference. so if you're not bothered with the loudness, go for it. it's an excellent system. there are others that are quieter, and IMO at least, sound better but also provide decent flow. for boosted applications, the N1 is easily one of the top choices. if you're not boosted, i'd also recomend the thermal or mugen(though pricey).

and yes, the carsound is 50 state legal.

So which is quietest, and will still give you gain over stock?

So which is quietest, and will still give you gain over stock?

the quietest exhaust would probably be the apexi ws catback. almost like stock and yes it'll give you a little bit of gain. forget about it if you're going FI though.

my setup is stock, except for bolt ons. i have an AEM intake, a dc sport 421 ss header, but aside from that, shes stock.

u mentioned that the N1 is loud...loud as in annoying lawnmower BWAAAAAAAAAAAAAAAAAAAAAA loud or loud as in db level.

im probably not going to go FI, too much $$$, so i dont need a setup that will allow me to do that in the future.

thanks for all of your helpful responses!

the quietest exhaust would probably be the apexi ws catback. almost like stock and yes it'll give you a little bit of gain. forget about it if you're going FI though.

Sure wish they made one for a 4th gen...

How would you rate the DC sports exhaust? It's that, or the greddy SP for now. Can't stand my piece of......

my setup is stock, except for bolt ons. i have an AEM intake, a dc sport 421 ss header, but aside from that, shes stock.

u mentioned that the N1 is loud...loud as in annoying lawnmower BWAAAAAAAAAAAAAAAAAAAAAA loud or loud as in db level.

im probably not going to go FI, too much $$$, so i dont need a setup that will allow me to do that in the future.

thanks for all of your helpful responses!


both, it can become annoying after a while on the highway. it does come with a silencer, which helps a little. and since it's a straight-through design, the db level is up there.

Prelewd, never was a fan of the DC exhaust. it doesnt' sound bad, but there's better overall systems available. b/w that and the greddy, i'd go with the greddy.

which exhaust would u recommend that would produce a rich deep sound with my setup, del?

which exhaust would u recommend that would produce a rich deep sound with my setup, del?


i mentioned the thermal or mugen. those two are great exhausts. the mugen is hella expensive though. check into those.

Thanks del. Think I'm going to order the greddy SP tomorrow, but I'll sleep on it. Need a new h23 though..

i heard that catbacks drastically drop your mpg, is this true? and if so how much is drastically....cause i know an ordinary 4th gen manual gets 29 highway and like 25-27 city, how much would it be with a catback, do different cat backs affect it differently, and if so why? Thanks

At the import show down in Tacoma last weekend there was some group that deal through (i.e. you can order-through) Napa stores that was trying to get word out on their stuff, I left the catalog at work; but they had a polished stainless header & catback w/ muffler choices & resonators, etc., that were mandrel bent of course, and pretty affordable. I guess the big question is how would they perform since I doubt there's many out there yet, but I'll try to remember tomorrow to log on from work & post the name. It was a 3-letter dealie, like NZX or AXZ & I keep thinking it had at least an X or Z in the name if not both.

Regardless, I'm new to Preludes, but what I know of exhaust systems, I tend to trust Greddy & have recently heard a lot of good things about the Thermal as mentioned above, too. Since I'll be doin' one myself for my '97 next month probably, hope to keep this thread rollin' ;)

It was a 3-letter dealie, like NZX or AXZ & I keep thinking it had at least an X or Z in the name if not both.



Wasn't OBX was it?

Anybody heard anything about megan mufflers. I'm not really considering these, but have seen them on ebay quite a bit, and was wondering about the quality of them.

Wasn't OBX was it?

Anybody heard anything about megan mufflers. I'm not really considering these, but have seen them on ebay quite a bit, and was wondering about the quality of them.


Nope, turns out the new guys (at least new to me, never heard of 'em) are *DNX*. Not sure if they're good, but they're cheap! ;)

Nope, turns out the new guys (at least new to me, never heard of 'em) are *DNX*. Not sure if they're good, but they're cheap! ;)

Usually, cheap != good. I'll have to look them up anyway though.