h23a downpipe on h22a header. - Honda Prelude Forum

LudeDrew · 08-31-2002, 03:22 AM

I am in the process of swapping my motor into my car...about to lower the motor into the car....anyhow....

will my h23a downpipe fit my jdm h22a exhaust manifold? i only got the top half when i bought my motor

Machine Head · 08-31-2002, 03:24 AM

I don't think so, not wothout some modification to the flanges

LudeDrew · 08-31-2002, 03:30 AM

guess ill go to the junkyard and buy it then....will my cat fit the downpipe?

Absolut · 08-31-2002, 11:28 PM

Your in for some fun....
I did the same thing.. h22 into Si.

You have 3 options:

A: Get a VTEC downpipe and cut the flange that bolts to the cat off. Now cut off the same flange on the Si downpipe and weld it on to the VTEC downpipe. This setup will allow you to buy an exhaust system made for an Si and it will fit. Unless you buy a header, then it most likely wont.

2: Buy a VTEC downpipe(or complete header) and buy a new cat and entire cat-back exhaust and bolt everything up to the car. (this is what I did)

D: You might be able to elongate the holes on the VTEC downpipe to make the SI catalytic bolt up, but you might just wind up with a horrible exhaust leak and a ruined downpipe.

Good luck, pm or email for more info.