00 Si

I read some where that there is some modifications that you have to do to fit on a B16A2 but not sure. Can someone tell me if you have to modify anything or if it is a direct bolt up. Thanks in advance.

DragII

It will bolt up to the head, but not the cat


Go aftermarket, much less headache...same if not better power gains

RacerXI

What Drag said...you're either looking at an OBDII compliant test pipe * won't throw CEL* or a 2.5" carsound cat or something to that effect. Good luck with it.

00 Si

How much is the cat and where can I find it? Will it bolt directly to the aftermarket cat with no problems? What kind of modification am I looking at if I keep the factory cat?

RacerXI

if you keep the factory cat, you're looking at rebuilding the inlet to your cat to accept the 2.5" collector. If i were you, i'd just pick up a test pipe or 2.5" cat.....to think of it down the road, you may want to replace the header setup with your stock cat and exhaust manifold. You won't have it all hacked up. Try this place.....you might want to e-mail him personally to make sure it doesn't throw a CEL i hope it's not down right now http://www.godspeed.hack.net/

ElectronVTEC

The JDM 4-1 is a damned nice header. I can say for sure it'll support at least 200 whp . The nice thing is that with the factory heat shields, no one even notices the damned thing... plus its butt-*** ugly so do us all a favor and get the heatshields too. Peace, EV.

00 Si

I have a Comptech header right now. Will it benifit me any to get the JDM piece or should I just keep the Comptech header?

RacerXI

I think unless you were planning on building a serious NA car real soon the comptech header will work just fine. The comptech header is a nice piece. Maybe EV can shed some light.

DragII

The comptech should make more power than the stock JDM manifold....think about it....why would they sell header in japan if you wouldn't benefit from them?

ElectronVTEC

Uh, just cause they sell it doesn't mean it will work. Take the Pacesetter header... you think that thing actually makes power and *wont* fall apart in a year? Riiiight. As for the comptech vs JDM 4-1, the main reason to get the JDM is for the 2.5" collector as it seems to be more appropriate for cams that are larger than stock. The comptech isn't a bad header but can you honestly tell me they know more about B-series engines than Honda? That may sound like a weird reason but I used the JDM 4-1 because its engineered by the same people who designed the B-series engines. IMO, it was worth the trouble and I'm not even thinking about going to a high dollar JDM 4-2-1 as I dont see much of a gain to be had. Peace, EV.

ITR764

the deck hight on the b18c is higher than the b16, so the jdm itr header will hange lower.

sloppy_seconds

the jdm ITR header is mostly for high end use...this meaning that some of your low end torque will disappear when the header is installed. too much $ to modify your car install a header if you already have a comptech one!
--justin

Kengs

Good point. My favorite car wash place won't take my Si now

Still, you can't beat the bang for the buck, even if it is butt-ugly