My RX4 wagon has the original exhaust. The whole thing from manifold to thermal reactor to tailpipe. The whole nine yards.

I have been told these exhausts are worth some money. I don't plan on selling it, but I was thinking it made sense to preserve it. Then I would be able to take it back to original if necessary.

So, I was thinking about getting a mazdatrix header and presilencer to replace my original exhaust. Then, obviously store the original. I was told this would increase the horsepower by 20-25. Is this realistic? Not that I am really looking for a hot rod right now, but an extra 25 hp would be nice.

Thoughts?

 

I doubt the old one is worth much....however, it's not a bad idea to hold on to it if you think you might want to restore the car years from now.
As far as picking up more ponys, it depends on the year of the motor. As I recall the 74-75 13b's had the larger exhaust ports and will benefit considerable more from a complete exhaust than the later "early" 13b motors. If it is a 74-75 then I could see you gaining up to 25, sure.

 

Are you the owner of the yellow wagon I have seen around? The one with the turbo engine swap and the coupe style bumperettes (not to mention the other cool stuff)?

I am going for a watered down version of the yellow one. Not quite as nice since my skill or pocket book could not handle it.

 

right on man, yeah thats me. thanks.

 

I installed an RB system on my bro's blue RX-4 wagon. RX-4/Cosmo header, presilencer, '83-'85 muffler. I had to customize the pipes going into and out of the RB muffler to fit the RX-4 chassis. In the end it was worth the effort because it flows well enough to breath up to 8k with a supecharger.