Finished with cosmetics and am now moving on to performance upgrades. I have my mind set on an Apexi World Sport 2 catback and some U.S.-style Type R headers. I'm looking for something that will give me an immediate horsepower increase but is still large enough to be effective after I've put a little bit of work in under the hood. I'd like to only have to buy this once. My goal is about 220whp N/A. My friend recommended 2¼ inch. He said any bigger would wear on my wires and plugs. Would that 2¼ inch get in the way later on? Or would it still be helpful after mid-level mods? Thanks.

 

N/A huh? How many miles on your motor? And what motor?

 

140k b18c1

 

2 1/4" exhaust or bigger will wear on your wires and plugs?
I dont understand.
Id say closer to 2.5" exhaust piping to support 220whp.
As far as headers go, SMSP,RMF,Hytech,Rage all come to mind when I hear about a potent high hp all motor setup.
The USDM ITR exhaust manifold is cast iron I believe, while the JDM 98+ get a better flowing 4-1 tubular header, not cast...Im not sure if a JDM ITR header will flow enough for 220 whp, (might be a little restrictive)...

 

Thanks. I wanted the USDM's because like 6-7 months ago I read an article in Turbo magazine about headers in their project GS-R. They dyno tested 4 different types of headers: DC Sport 4-2-1, DC Sport 4-1, USDM Type R, and JDM Type R. The USDM's gave the biggest hp increase. Of the ones you just mentioned, is there a particular one that you think is better than the rest?

As for the plugs, I had no idea that that was even an issue when upgrading H/E. I thought the only problem you could run into was that if you went too big, you lose power because your exhaust gases would lose velocity rather than flowing quickly out of your pipe. I didn't talk to my friend for long, but he said that bigger than 2¼ inch would damage them over time (my guess is that if it's true, it's like a slower version of how running nitrous can melt your plugs). I really don't see how another ¼ inch would really hurt, so 2.5 it is

Edit: Alright, I decided on RMF, but I'm having trouble finding someone who sells it. Anyone know a place?