Hey everyone, I have a Mugen H22a header that came off a 94 JDM Accord. This would be perfect, since I have an H22 in my project Accord, but it is going to have to be modified; I measured the collector and the ID is only 2"!!

I will post pics if someone can host, but I could not believe that it was only 2", even my JDM downpipe was 2.3 or around there at least.

It was odd, right after the flex pipe, it narrowed down into 2". My assumption is that since it was meant to be a bolt-on mod for the JDM H22 Accord they tapered collector to fit the stock cat. Makes sense right?

Anywho, what I was planning on doing was to have the collector modified to about 2.5in at the flange where it meets the cat, and taper it back to the Y-pipe. (Right after the Y-pipe, it looks like it is 2.5in OD, but most likely 2.3in ID.)

My question is if a Flex pipe is recommedended? I noticed the SMSP, Prodspeed, etc do not have flex pipes and I am thinking maybe I could skip the flexpipe.

Any thoughts on this?

 

You should use a flexpipe to prevent your welds from cracking over time. You might be able to get away without the flex pipe if you use the donut flange.

 

Also you might need to change your flange. I have a jdm rsr header and I had to modify the flange. The flange looks similar to the usdm but the bolt pattern is not the same.

 

Thanks for the advice. I was going to buy 4 matching flanges since I was going to go with a high-flow cat.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by luderacer22 &raquo;</TD></TR><TR><TD CLASS="quote">You should use a flexpipe to prevent your welds from cracking over time. You might be able to get away without the flex pipe if you use the donut flange.</TD></TR></TABLE>

has anyone had problems cracking their welds even while using stiff motor mounts? with SS that is....