Type R Club of America

Without diving into the internet rabbit hole, does anyone have comparison notes and side-by-side pictures of the USDM ITR header (exhaust manifold) and the JDM 1996-1997 '96 spec header? Details would include upper and lower manifold dimensions, heat shields, necessary Cat length, etc. USDM and '98 spec headers are getting really difficult to find, especially with good condition heat shields. Are '96 spec headers a good option?

I like rabbit holes.

If it helps your search, here are some good pictures of JDM:

https://page.auctions.yahoo.co.jp/jp/auction/h576862277

https://www.ebay.com/itm/224447589007?e ... SwHYdgjueY

Note in the latter ebay link the headers are advertised as a good replacement for USDM.

https://www.amayama.com/en/genuine-cata ... &fromMap=1

https://www.acuraoemparts.com/v-1998-ac ... manifold-2

Here are diagrams that clearly show the main differences, I suspect it would work well with minimal modification.

I went down this rabbit hole a while back.
Hoping that the 96 header would be easier to carb and might be more compatible with the Twinloop (provided a custom welded carb cat).

Ultimately I decided was easier to drop a carb header in, custom cat and modify bpipe a as needed to allow swapping in systems I want to run.

If an alternative for usdm be careful it has the same large outlet 98+ JDM do so cats will be custom and you may fail visuals, if subject.

There are many reasons to do custom setups but I recommend just finding a quality fabricator and having any sets you want to work together modified to your purpose, it’s a cleaner end result and less frustrating.

Stupid question, if the 96 spec header has the 2.5in outlet to the cat, could you use a top part of a 96 spec header with an USDM LS bottom portion to pass a visual inspection if it bolts up?

aw614 wrote:Stupid question, if the 96 spec header has the 2.5in outlet to the cat, could you use a top part of a 96 spec header with an USDM LS bottom portion to pass a visual inspection if it bolts up?

I did check this but LS lower won’t clear the ITR trans brace and the flange appeared to be at a different angle. I don’t see this combo working.

I don't have measurements but I also went down this rabbit hole. I know you want OEM look but I don't think I would use the 96-97 2 piece JDM header. Might as well go with a quality header if you can't find a JDM 98 spec with shields.

My suggestion: Quality header, aftermarket cat, Spoon or other mid pipe, Spoon street muffler (if you want close to OEM look and sound).

I went from RMF header, Vibrant cat (it was toast and smelly), custom mid pipe and Hytech twin loop (loved this exhaust and miss it).

Over the last year I managed to piece together JDM 98+ 4-1 header no dents (local Garage Five), upper and lower shields (local Type R owner), JDM cat from JDM Ohio (with shields), JDM OEM mid pipe from Jspec Calgary Alberta and JDM muffler (local Type R owner). It is difficult to find all these parts now.

Even all this was still some work. JDM cat has a heat sensor so I had to get that drilled out, get an o2 bung welded on and then use a defouler because the cat is not the same as USDM. I purchased new heat sheld bolts (there are a lot). I had the header heat shields cerakoted black and the JDM cat shields done in high heat silver. I refinished the muffler with high heat flat black. Small ding on the tip repaired by dent removal company. The B pipe was a pain to get here because its one piece and very long. Had a buddy who transports cars end up moving it when he happen to have a trip Calgary to Victoria BC.

The real downside is I have a defouler for the o2 sensor. I just wanted all OEM JDM. To do it properly you may as well go aftermarket cat to pass all inspections.

JDM cat if anyone is looking

https://jdmohiodirect.com/jdm-96-00-civ ... -converter