Well Im getting my RB header and presilencer on soon, and was thinking of what to do about emissions. I was just going to swap out the presilencer for a cat once a year when I need to get it inspected, but was thinking of just maybe putting in a high-flow cat instead of the silencer, to just save on the hassle, also not have to worry about getting a ticket or something for having no cat. Will there be a noticable increase in power in favor of the midpipe as opposed to a bonez high-flow cat??, or will the difference be minimal? If there is a big differnce ill install the midpipe and just swap out for the cat when I need inspection, but if I probably wont notice a difference Ill just leave the cat on all year.

 

IMHO, on an NA with regular bolt-on mods, you won't see THAT big of a difference with the high-flow cat - maybe a few horsepower, that's it. Might be worthwhile to stick with it, considering you already have it anyhow.

Dale

 

Thanks, anyone else have any input?

 

my car is faster with an intake and high flow cat, then mid pipe and stock air box if that helps any

can't run a midpipe with intake or the boost goes too high

the cat will be much quieter as well. which you will want with the headers!!

 

Since you are getting the RB header, you'll either run the presilencer or a custom catalytic. Power difference shouldn't noticeable since most NEW higher flowing converters do not eat as much power as people think. Mazdatrix sells the RB header with a cat and calls it the GRAY area exhaust. If you look at the cat pictures, you will see that they added an extension to it so that it is a direct bolt on between the header/catback.
If you use your own catalytic, you'll need a muffler shop or competent welder to make the extension. Problem with catalytics is that they wear out with time. Cheap ones won't last long.
You might be better off swapping for each inspection and keeping the hardly used catalytic in storage until it is needed again.

 

Well I have the Bonez Superflow system on my car now. Its less that a year old, and if there was not a noticable difference I was just going to cut the cat off of that and have extensions and pipes welded on to the ends to make it fit. I have access to welders, and my Dad welds for a living so that wouls be no big deal. I already have the RB silencer, but was just going to sell it as to not have to hassle with swapping it out once a year. This all, of course, is if there is no major loss from a midpipe to cat. So you are saying that the difference in power will be pretty much negligable?