I've tried to search but not found all the answers I need. I'm looking into what parts I need to fit a JDM 4-1 header to my UK ITR. My ITR has a 17inch cat as standard, I don't know if it's the same on the US version but thought I would ask.

OK I want to use the original cat for MOT purposes (the yearly test that checks on the road worthiness of vehicles in the UK and also the only time the emissions are checked), but will get a 2.5inch replacement pipe made for road use.

Eventually I will get a custom 2.5inch b-pipe and rear box made up but to start with I want to use the standard b-pipe and exhaust (so I don't have to spend cash I don't have yet).

So question is: If I get one of those 2.5inch flange adapters can it be used with the standard cat to fit onto the standard exhaust? And will I need to have the b-pipe "cut-back" to make up for the extra length in the cat+adapter or is the JDM 4-1 header shorter than the stock header?

Thanks in advance for any advice

Richard

BTW if this has already been discussed sorry and can you directly me to the threads.

 

Hi there, welcome,

I saw a Type R at SONY Basingstoke 3 months ago. Was it yours?

You need 2 of those 2.5" flanges. One for your stock cat and one for the test-pipe.
You can cut the flange of the stock cat off, but be careful not to damage the cat material inside. When you are using the stock B-pipe cut the B-pipe flange (restriction) and put a 57 or 60 or 63 mm flange on it (depending on your test-pipe outer diameter)....

 

Have you considered purchasing a 2.5" aftermarket cat fitted for your car? I would (and am) going with this option for 3 reasons:

1. Smell/Emissions ...you car will stink without a cat (at least from behind it will be)
2. Sound, unless you plan on getting another resonator, you exhaust system is going to be buzzy (tinny sounding).
3. High flow cats give almost the same performance gains as a test pipe.

Any good muffler shop will flange up a high flow cat so it fits your car.

 

No I don't work there but I live very close (in the Brighton Hill estate)

So the minimum I would need is the 2.5" flanges (would that be the ones from inlinefour.com), I could then hook it up together without modifying the b-pipe?

It will only be a temporary measure until I get the catback made up in 2.5" and at that point I will get a proper 2.5" test pipe made too.



[Modified by HardHead42, 12:03 PM 2/28/2002]

 

I have been running a test pipe and not had these problems although my current test pipe does have a resonator on it (checkout http://www.supersprint.com).

 

You don't have to modify the B-pipe to make it fit. It's only needed for the extra power because there is a bottleneck there. I would recommend the 2.5" test-pipe put on it together with the header and the cat-back later.

 

Thanks for that, So I think my plan will be, get one flange and modify my cat to work with the JDM header, and get a 2.5" test pipe made up at the same time. And then sort out the 2.5" catback system later.

Thanks again.

Rich

Just a thought, can the flange be sleeve jointed to the original cat or does it have to be welded in (wondering if I can use one flange for both my cureent cat and current testpipe)

 

pictures for your viewing (borrowed from ITR-NC.com)

universal cat.... 2.5" cat-back





Will

 

A bit more info here --> http://www.itr-nc.com/pages/jdm_4.htm

 

Thanks for all the help. BTW what's the overall length of the cat on that picture?

Another related question, what header would people recommend for someone with a stock ITR that may want to upgrade to TODA B or JUN III cams? Any real difference, I saw the the header test and they all seem pretty similar on a stock ITR.