I am buying a DC JDM header, and need to know what the flange pattern is so that I can buy the right high flow cat to attach it to.

Thanks in Advance,
JP

 

I know that there is more than one person in this forum with this header?

Could somebody please help me out?

Thanks,
JP

 

JP, it is the standard 2 bolt flange, but it has a 2.5" collector. The donut gasket you will need is the 2.5" gasket used on the S2000 exhaust manifold, 22$ at Honda. The Cat you need will have to be custom, 2.5 at the header end and setup for the 2.25 USDM bpipe connection. I can HIGHLY recommend that you IM Dave (SMSP) he has a jig and exact dimensions and will make you a custom high flow cat that will fit perfectly. he will even include new bolts, retaining springs and bpipe gasket. I have this setup on the Yellow and it is awesome. Also, the USDM header bracket will crack if you attach it to the JDM DC, so dont even use it.

 

I second not using the header bracket on the DC JDM, mine tore in half and the car sounded terrible until I finally found what it was and removed it.

 

Thanks for the info SlapSmak, very helpful.

I am going with a custom 2.5 inch exaust however with the new header, and this will eliminate the need for a special cat I would assume.

I would like to go with something from SMSP, but at this time I don't think its in the budget. I am going with mandrel piping, cat, resonator, and magnaflow muffler from KTeller8 right here on Honda-Tech.

Thanks Again guys,
JP

 

Bringing this thread back from the dead.

Just verifying to see if the DC JDM 4-1 flange is in fact 2 bolt?

TIA

 

Good shot of the DC JDM 4-1 collector flange: