3" or 2.5" inch cat. converter????

[SinEclipse]

i dont know much about these stuff so please dont go crazy on me if this is a stupid question. im looking on getting a high flow cat since the car doesnt have one but i dont know which im suppose to get the car have an apex'i n1 dp and apex'i n1 exhaust. so do i get the 3" cat. converter or the 2.5" cat. converter for this car?

 

[TalonTSiGuy]

since you live in california, and if your not insanely serious about your car, id go with a high flow cat. But if your wanting max perf. id run no cat.

i also live in cali and so do most of my dsm buddies, and we all run with no cat, and have never gotten in trouble for it. Its just gonna be a pain in the ass when we have to go get smogged


So its up to you.

 

[leakyfaucet]

Uh, he was asking which size to get...

I believe the N1 is a 3" exhaust which would lead me to believe you should get a 3" cat but check with someone else to be sure.

 

[SinEclipse]

so i should get a 3" cat. since i need to get the car smog soon

 

[rghrdr18]

The Apexi can come in either 60 mm (approx 2.5 inches) or 75 mm (3") on the N1 exhaust. If you find out which one you have, then go with thte same size high flow pipe.

 

[SinEclipse]

oh thanks alot, but one problem that car came with the apexi n1 so how do i check if its a 60mm or 75mm

 

[midnght]

Unbolt the cat that is in there and measure it.

 

[SinEclipse]

alright thanks alot for the help ill do it when my brother gets home since he got all the tools. i think its a 3" but gonna measure it just in case. since when my uncle jacked up my whole car he said it was a 3" but he was unsure

 

[Generation1JeY]

wouldnt u have to get one that matches ur downpipe and catback size? if u have 3" high flo cat and 2.5" downpipe and 2" cat back can u even put those together with the flanges they come with?

 

[kmartind]

It would require cutting and welding either way since the N1 downpipe is "long" and eliminates the cat. I'd probably go with the 3" high flow cat with a flange welded on either end, and the same size flange welded onto the downpipe after cutting it to the right length. Then you could swap in either the test pipe or the cat as needed. It will then look something like the bottom pic here: http://www.roadraceengineering.com/parts/dp/rredp-2gfwd-options.jpg

Alternately just put your stock exhaust back on temporarilly (or borrow one). That might be easier and won't raise any eyebrows on the visual inspection of the exhaust.

 

[SinEclipse]

ill be gettin that cat. converter since i dont know any with a 2g eclipse gst that would let me borrow his exhaust

 

[SinEclipse]

forgot to mention where would i find that cat. converter in that picture.

 

[kmartind]

forgot to mention where would i find that cat. converter in that picture.

The picture was from Road Race Engineering:
http://www.roadraceengineering.com/eclcatalogindex.htm
They should be within about 20-30 minutes of you. I think most any exhaust shop should be able to fix you up though. Even if you get a cat with the right flanges already on it (like the RRE one) you'll still need to modify the N1 downpipe or replace it with a "short" downpipe to have something to bolt the cat to.
You could also try dsmtrader or ebay to try and save some money, but be sure you're actaully getting what you need and not something that won't fit.

 

[SinEclipse]

thanks for the help. i jack it up found out i got a 3" and a long dp