The Mugen 4-2-1 header is great, it's just mad loot, and for the same price the Toda header is supposed to make a little more power. As far as JDM cat, you really just need a 2.5 inch collector welded onto your cat, but a JDM cat would work too....

Later,
Aj

 

weld some cheap piece of metal to my (possibly soon to be) expensive Mugen Header and Exhaust!?!? lolx.
Anyway, do u think the 4-2-1 design produces more torque than the 4-1 does?

 

another thought...the stock exhaust manifold is kind of restrictive, so an aftermarket one would be beneficial, but isn't the stock ITR exhaust flowing pretty nicely already? maybe i should just keep it, and swap out the header, and with the $1000 saved from not buying the exhaust, i could buy some internals...maybe cams...?

 

well, about welding something to your cat, if you have it done right and don't skimp out on it, there are plenty of places that do tig welding, that will look perfect, I mean, go forbit someone might look under your car and see some nasty welds...lol....any way, neither the stock manifold or exhaust are very free flowing depending on what you have done, if you need a lot of flow, the stock stuff isn't cutting it.

The 4-2-1 design doesn't necesarily produce more toruqe, it just produces power in different places in the rpm band, and depending on the modifications done to the car, it could be more or less torque than the 4-1 in different places. Hard to explain, it's mainly mid range power with the 4-2-1, and mainly high end power on the 4-1.....

And, with a thousand dollars, you really can get a set of cams and a valve train, so you might as well get a really trick exhaust and just save for cams at a later date


Later,
Aj

 

so, which (in ur opinion) would u go with...4-2-1, 4-1?
(i'm kinda wanting to go 4-2-1 myself, but i'm asking for opinion, and why u think so...

 

4-2-1, it's got more ground clearance, and creates more midrange power where most hondas lack power. Not only that, it looks mad trick.

Later,
Aj

 

great...so u can verify the need for the JDM cat, or a 2.5" collector with the header?

(man, and I was gonna go ahead and order it right now)

 

You can do either. A JDM cat is 2.5", as is the collector size on any JDM-spec header (Mugen, Toda, Spoon, OEM) so you can bolt that directly on. Or you can modify your stock US cat by cutting off the header side collector and welding on a larger 2.5" one.

 

is it a bad idea to get the headers flange changed to in case i wanna keep my cat intact so that i can re-switch headers to stock for my guarantee.

going the test pipe route is probably annoying as hell on the highway huh?

 

You would not be able to simply switch the header collector to a 2.25 inch collector. If you were going to do that, you might as well get a much less expensive header that already has a 2.25 inch collector, as you will completely screw up the flow characteristics by welding on a different flange, not to mention, that's not something that can easily be done, correctly at least.

Aside from that, why would you modify your header to keep your stock cat intact, get a test pipe...to keep your stock cat would be dumb any way, you'll have a 2.5 inch collector on a very free flowing header connected to a 2 inch cat, what point would that be, you'll defeat the purpose of the header, or at the very least minimize it's power potential. Either that, or if you want a cat, get a high flow cat like a random technologies cat or something, that has the option of a 2.5 flange. If you need to take something in to the dealership, more than likely they won't say anything about a header, unless it's directly related, but if you're really paranoid, you can just pull the header and either test pipe, or high flow cat off, and put your stock stuff back on.

Well, what ever you decide, good luck with it.

Later,
Aj