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ITR header thread

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81K views 557 replies 126 participants last post by  REVmore 
#1 · (Edited)
Here's a cut and paste of my install thread from ephatch. Got the idea and a lot of the info on here so in the interest of giving back thought I'd post it up. The install as detailed is for the Ep so there are some differences for the DC5 -- 1) stock sway will not work and 2) midpipe is not needed.

Why you want it:
It's essentially a race header -- 4-2-1 with a metallic cat. Not polished and pretty, but don't see it on the car anyway. And you're getting factory looks, fit, and reliability -- no banging on the subframe or flex joint failures and a smog tech or cop can't tell it from stock.

What you need:
It's bolt-on -- a simple remove and replace with a few extras required. You will need: 1) ITR manifold and cat, 2) type-S or ITR midpipe, 3) 6" extension lead for the secondary o2, and 4) gaskets -- that's it. NO clearance issues with stock front sway.

You reuse all the factory hardware, in addition you will want/need:
gasket @ head --- 18115-PRB-A01
gasket @ b-pipe -- 18393-SS0-J30
gasket @ flex ---- 18212-SM4-003
donut gasket------ 18229-S01-X11
12mm nut (x2) ---- 90215-SB0-003 (for 2nd downpipe)

All available from US Honda.

Sourcing the parts:
Expect $300-500 in parts for the install. There are deals out there, but beware, you will spend more in the long run fixing a piece of junk.

Manifold: get it from one of the JDM motor import vendors or classifieds on clubrsx.
1) it will be rusty, just surface rust, doesn't affect function. Options are: have it blasted and ceramic coated or buy new from Japan ~$300 shipped.
2) the heatshields will probably be dinged or missing. If they're beat, don't see them on the car anyway. Missing, go naked or get them from Japan ~$50 each shipped.
3) the studs will probably be damaged or missing, either means machine shop repair. The studs are not available as a separate part from Honda or as generic hardware because they are 1.25 thread pitch. Replacement options are: 1) use bolts -- 12mm, 1.25 pitch bolts are available. 2) make studs by cutting the heads off and threading the head ends of 1.25 pitch bolts. 3) have the machine shop rethread or helicoil the manifold to 1.75 pitch -- these studs are available. Conclusion: find one with good studs or pay very little for it because there will be a repair bill.

Cat: same source as the manifold, make sure it has shields and isn't bent from accident. If the studs are damaged, these are available from Honda US.

Midpipe: they're cheap used if you can find one local on craigslist or clubrsx -- got mine for $50. But because of length, package will be oversized so probably won't pay to ship. Can't find used local, get it new from Acura ~$150.

o2 extension: get it here, call them for custom length:
http://www.casperselectronics.com/m...e_Code=CEI&Product_Code=109200&Category_Code=

The install:
Same as a race header. You will need to R&R the axle guard and the swaybar clamps for clearance. Use the ITR rubber hangar on the cat if you have it -- hangs 1/2" closer to the bottom of the car. VERY IMPORTANT: make sure you install the lower heatshield onto the manifold before installing it to the head, it's a bitch getting it on after.
 
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#536 ·
Sorry to revive an old thread, but;

Does anybody know the exact size, correct length, of the bolts i can use to attach the upper to lower manifold, the ones where the JDM studs are ripped out from the ITR that it was pulled out of?

Clearance is tight, and the nut and bolt set I have I'm not sure if the bolts are long enough to safely attached the upper manifold the the 'non-flex" pipe on the lower piece.

If anybody knows exactly what I can use to attach that side of the lower pipe to the upper manifold it would really be a great help. This has been sitting in my garage for 4 years because I can't figure it out.
 
#542 · (Edited)
Im getting tired of removing my header for ca emissions so I'm going to do a tune with the itr header and simple bolt ons. I got my itr header for $120 because it had a stripped bolt but i got that fixed at no charge
:D

I was surprised the header was complete( not missing any bolts or heat shields) I bought the itr header/cat here on the forums. All i needed for install was a 02 extension and it was an easy install. I'm now in the market for a em2 sway bar and I'm currently driving without a sway bar.
 
#551 ·
When my header/exhaust is up to temperature I'm getting this weird popping noise under the car around the center dash/console upon releasing the gas or even just cruising slowing down in neutral. I honestly can't tell if it's just bumping the chassis or if there's an issue with the header. Any ideas?
 
#553 ·
I finally got my ITR exhaust manifold and cat along with the 06 RSX-S b-pipe installed on my 03 EP3. I have a few notes:

I bought the ITR exhaust manifold and cat with all the heat shields from hmotorsonline for $330 shipped. My brother used his dealer discount to get me a brand new 06 RSX-S b-pipe for a little over $100.

I had my local shop do the install. They quoted me $130 but it ended up being $180 because two of the bolts had to be drilled out and re-tapped or whatever it's called.

I have the stock 03 EP3 front sway bar and there are no fitment issues.

The car sounds basically stock at all engine speeds. It has a little bit of a deeper tone in spots of the rev range that were deep to begin with. I also noticed that the engine is smoother now. My fiancée also noticed this fact.

The car has better throttle response and pulls a bit harder at the top of the rev range. I can still hear my intake over the exhaust at WOT.

It feels the same if not a bit better than when I had a DC race header and Greddy Evo 2 exhaust while still sounding like stock, which is exactly what I wanted.

Overall I am very happy with both the sound of the exhaust system and the increase in power. Big thanks to everybody in this thread who contributed. My mechanic had never done this install before and he thought it was a really cool idea. The shop I go to specializes in Hondas and Subarus.
 
#554 ·
I recently got and refreshed an ITR header and this thread was worth gold in information and so I would like to contribute my experience with the install. Much of my time was spent on removing heavy rust from the header and cat system. I purchased all new hardware/gaskets for it with the part numbers off the first page. I also went ahead and got new nuts that attach the cat to the b-pipe since mine were heavily rusted and very difficult to remove.

The nut used that attach the cat to the b-pipe is part 90212-SA5-003 and I replaced all three using plenty of anti-seize compound.

My example also had the common issue where on the upper header, the two threaded bolts that attach the upper part of the header to the lower half needed replacement. I grinded off the spot welds with a Dremel rotary tool and then removed them with a very large pipe wrench and help of a friend. The threaded replacement bolts were difficult to find since as stated before Honda doesn't sell them separately; but with enough searching online, I found a Mazda replacement that is the exact same diameter and thread pitch, just 10 mm longer.

It is Crown Bolt M12-1.25 x 50 mm Catalytic Converter Mazda. It can be ordered at a variety of places online, but the only place I found it sold in pairs instead of a set of 4 was home depot online.

After those were tack welded in place, I painted the header inside and out with Eastwood's Internal Header Coating to protect the bare metal from rust. I worked hard removing the rust and I wanted to make sure it stayed away. AND the coating is rated at 1800 degrees F. This is my first time using this paint and I find it works very well. It coats well and looks great. Here is a pic of it before it was installed with the new bolts. Also a pic of the heat shield restored the best I could...

In terms of performance, my car is stock without any ecu tuning, so I really didn't feel much difference other than smoother power delivery. Slightly deeper tone at certain rpms and the general impression that the engine is breathing better. I'm glad that I have no CEL's since originally my secondary was telling me I needed a new cat on my stock system. I know that until I get some form of ecu tuning, the header is not being utilized to it's potential. Overall, exactly what I was looking for since my car is daily driven.
 

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#556 ·
REVmore,

You did some great work with the upper section - It looks clean and functional. Nice man! I am looking to go the same path and had a few questions:

1. Did you clean up the Cat section as well? Any recommendation?
2. What front sway bar are you running? Did you have any clearance issues?
3. Where did you source the header? I have found a few outlets but lead times are excessive.

Nice post and I enjoyed seeing your work!

-eric
 
#558 ·
Hey Ericcarver1,

My apologies for the extremely late reply~

1. Did you clean up the Cat section as well? Any recommendation?

Yes, I did. Not nearly as cleanly since the awkward shape. for the actual header section, i soaked it in a tub of vinegar (add salt) for a day. This made getting the rust off a lot easier. I couldn't really do that for the cat section since the awkward shape of it, so I just dremeled off what i could and sprayed it with the same paint. It worked well to my liking.

2. What front sway bar are you running? Did you have any clearance issues?

If you didn't search for it already, you have to use the EM2 Civic sway bar to clear. The only other sway bar that will fit is the ITR's, but you'll need the aluminum control arms to run that piece.

3. Where did you source the header? I have found a few outlets but lead times are excessive.

I was fortunate enough for get the header off a guy on facebook. If you have any other questions, please let me know. After being the original owner of my car since 03' I'm finally doing stuff to the car I've always wanted to.... Hope these answers help, Let me know if you have any other questions.
 
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