I was wondering what the power difference is between a full RB exhaust, and if I were to remove my own cat's but leave the rest stock.

Thanks

 

With just removing the cats it'll free up that section of the exhaust but leave behind the restrictions of the stock muffler and stock manifold. The RB system replaces the manifold with a high flow header and replaces the muffler with a more free flowing one, although it too is not completely free flow to help keep the noise in check

 

thanks for the tip i guess ill save some money

 

Take the time to research all of the options when it comes to exhaust. Some members have been researching alternative designs which might perform better and are significantly cheaper.

 

Did someone say my name?

The best upgrade for the RX-7 is a header. Racing Beat's short primary unit is a good economical upgrade that provides a very good bang-for-your-buck increase in HP. If you're looking for the ultimate in HP gain there are other, far more expensive, options for headers. In any case, I have the RB short primary header and one of their Powerpulse silencers which is their proprietary resonator. I think it's worth spending the cash for the RB silencer as it is a very good unit and does amazing things to the quality of the exhaust note.

From there it's really personal choice as to what needs to be done. I like my exhaust to be authoritative, but not loud enough to turn heads a kilometer down the street. With that in mind, I puchased a Magnaflow bottle silencer and a Borla Turbo muffler that was center in/offset out. Both are straight through stainless designs with perforated cores. If you do nothing else, stay away from baffled or chambered mufflers and anything with a louvered core. Chambers and baffles make the exahust change directions, slowing it down and causing restriction. Louvers create so much turbulance that they aren't much better than the chambered style, even though they are 'straight through.'

Anyhow, I like the Borla because it provides the best flow and noise reduction combo that I have found so far. It produces a very nice bass tone that is smooth and very pleasant to listen to. All the buzzing and harshness characteristic of the rotary exhaust is eliminated. I also used a second silencer because I hate excessive noise, but if you aren't bothered by a fairly loud exahust note (we're talking Honda fart can loud) then you can forego the extra silencer. I chose Magnaflow because they're cheap and very nicely constructed. Ditto for the Borla. Whatever muffler you choose, make sure it's stainless construction with welded seams. I used to have a Magnaflow main muffler but I found it to be loud and fairly buzzy and it lacked the nice bass tone that the Borla provided.

What I like best about this route is that I have a freeflowing exhaust that performs well and sounds great without spending massive dollars on the full RB setup, which apparently doesn't flow as well as other straight through designs like Borla or Magnaflow.

Here's an audio clip of my exhaust
http://members.shaw.ca/deuteronomy/Borla.mp3