JDM ITR 4-1 header into 94-99 GSR fitment trouble?

Y2K-DC

low n' slow
Would I have this same problem with a 2000 LS ? I'm also looking to install a ITR header.
 

SOMD_GSR_STi

Flatout Performance
Im running open header right now (i know all about the valve issue so im being careful) until I get my blox test pipe. my cat wouldnt bolt up but then again thats because of the 2.5 header with a 2.25 cat. ordered the Blox 2.5 test pipe that is adjustable too. Also had o2 in header and a port in test pipe as well so that way my HKS Hi Power can bolt up and ill be A OK. Just annoying as hell right now because its so loud, ughhhh
 

NemesisCBR

Boredest Member
Feel like this thread could use some more info. Research tells me the jdm itr 4-1 is the same length as all 94-01 integras except 94-99 gsr. Most are already familiar with 94-99 gsr being different than the rest. Research says the 94-99 gsr A pipe is 2" shorter than the others. The B pipe is also 4.5" longer than the others because of this and the cat is also shorter. 17.5" confirmed. Stock ID on oem usdm exhaut is 2" or 1.9". Usdm ITR is 2.25". JDM is 2.25" with collector and cat flanges 2.5". JDM cat is 12" and the jdm itr B pipe is 8" longer than usdm B pipes. Thus it is 3.5" longer than 94-99 gsr B pipes. This information suggests all other usdm cat lengths excluding 94-99 gsr are 20". Ive read different lengths for that so still looking to confirm via measurement. If anyones got one, whip out the measuring tape.

Ill edit post, info, organization as i get more solid numbers.

 

NemesisCBR

Boredest Member
I took some measurements trying to confirm some numbers on pipe diameter and got interesting results. Time and time again i have read that stock piping is 2" (i think usually implied ID) and itr is 2.25" (also implied ID). Either way people across the interenet have referred to them in both ID and OD measurements using the same number. Here are my results.

ls/gsr b pipe - 1.9" od 1.75" id
jdm itr b pipe - 2.24" od 2" id (id estimated, piping bolted on the car)
Skunk2 gsr b pipe 2.38" od 2.25" id

Measurements are within .01-.02" accuracy. When i get access to another itr b pipe im going to take new measurements.
 

gsr_nikhil

Member
Has anyone had trouble with a donut gasket from the header to cat? I can't find one that doesn't break or stretch from the heat leaving me with a leak :/

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TegSox

Super Duper Moderator
I didn't use a gasket between the header and cat, just between the cat and b pipe.


And just to reiterate for everyone: To put a JDM ITR header into a 94-99 GSR and you still want to use the stock B pipe location, you need a cat that is exactly 1 foot long.

I deleted some non-useful posts to keep the Sticky clean.
 
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NemesisCBR

Boredest Member
Really? No donut gasket and no leak?? In my research theres no gasket used cat to b pipe, theres a metal ring in the pipe if you look at both ends and they say this is used as the gasket. So i have the donut but no cat to b pipe gasket. With my aftermarket piping i intend to add a gasket there.
 

gsr_nikhil

Member
Would you recommend that or just welding a flex pipe to a cat then to custom piping

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covert_Con

Senior Ricer
Really? No donut gasket and no leak?? In my research theres no gasket used cat to b pipe, theres a metal ring in the pipe if you look at both ends and they say this is used as the gasket. So i have the donut but no cat to b pipe gasket. With my aftermarket piping i intend to add a gasket there.
I don't have a donut gasket and can confirm this. You've heard the sound clips. The bolts are tight enough, at least in my experience.
 


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