Anybody using a vibrant 4-2-1 race header on their itr ? I did search but didnt what i was looking for, ive also searched the all motor and read a couple good feedbacks. Basically a copy of the t1R.

http://vibrantperformance.com/...87514

 

https://honda-tech.com/zerothread/699674

it says its worse than the dc jdm header

 

haha oh snap =O

 

Hey Skanky, the vibrant header in this thread is not the 4-2-1 race header but the jdm spec 4-1

 

oh i didnt even notice that, my bad

 

hm..you're going to need a different cat as well. since it has longer runners.

 

Yeah i know, i already have a magaflow cat 2.5''

 

I run the 2539. Quality part, no problems at all with it even after a few years of operation.
I did have to trim the rear mount a tiny bit to get it in with my lower strut bar in place. Not a big deal at all but something to note.
Also, I’m not sure if it’s the 4-2-1 setup but when I first did the install I noticed that the car sounded like it was running a lower RPM than it did with the 4-1 OEM header. Not literally a lower RPM, same engine speed but different exhaust sound. This makes logical sense with a different merge setup, but I’m not sure if it’s the header or the design.. this is the only 4-2-1 I’ve had.

A stock cat with the collector flange enlarged slightly to accommodate the 2.5" collector works fine. At least it does when it's time for emissions testing. Normally I run a 2.5" resonator in its place.

note: setup, 00 itr swap in 92 hatch

 

did u get a good bang compare to the stock header ?

 

I didn't do back to back dyno runs to know for sure.
Butt_dyno says it did help mid range power a little. But I'd be willing to bet my butt_dyno needs calibration.

Honest opinion of the design, for a stock-ish 1.8 (see typical easy bolt ons) the primaries are a little large. I have a feeling the header was designed around a 2.0-2.2 or really really heavy breathing 1.8. With more aggressive cams and slightly higher CR I'd guess it would work better.
But on my setup with stock cams and CR it's not exactly what I was looking for.
I'm parting together an entirely different exhaust setup and planning on installing it when the weather plays nice in the spring. My 4-2-1 will be up for sale after that.

note: if you're expecting 15hp+ gains from a header you're going to be disappointed no matter where you go. Aim for +5hp and be presently surprised when it exceeds that.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Punkaddic &raquo;</TD></TR><TR><TD CLASS="quote">Yeah i know, i already have a magaflow cat 2.5''</TD></TR></TABLE>

i wasn't referring to the size of the cat, i'm talking about the length

this is from vibrant's website

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">This header will not bolt up to stock Honda/Acura catalytic converter. We recommend using our J-SPEC Header Outlet Flange kit (Part #2599) to make it easier to connect this header to a catalytic converter.</TD></TR></TABLE>

 

Maybe I read that wrong. But I read it as you need the reduction from the 2.5" to the standard 2.25" (defeats the purpose of it though)

looked up the part number...
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">The J-Spec Header Outlet Flange Kit was designed to make it easy to install Vibrant's J-Spec Headers or any header with a 2.5" outlet.

This kit consists of a 2-bolt connecting flange (with a flared outlet neck) and a 2-1/2" I.D. donut style Graphite Gasket</TD></TR></TABLE>

pic .. http://vibrantperformance.com/...L.jpg

 

my magnaflow cat has been already modified for a dc jdm that was on my old itr so it should fit, if not im a welder so no problem with that