Thinking about starting with just a header and then progressing as desired so I have a few questions.

1) if I do just the header, will it bolt up to my stock exhaust?

2) What will this gain me?

3) Does anyone sell the straight through replacement pipe that replaces the cat converter?

4) I want to keep the stock exhaust for now.. what will bolt onto what..

5) Or, should I just get the entire RX exhaust ( which curiously doesn't come with the replacement pipe for the converter.

Thanks
Peter

PS, not crazy about making the noise tinnier... hopefully this will deepen the note a bit..

 

1. no.
1a. the header pre-silencer combo does bolt to the stock "cat back" though

2. from stock? about 25hp

3. RB used to, im sure if you look you can find one, although 1a is the preferred option

4. see 1a. the stock system is manifold, 2 precats, 1 main cat, 1 connecting pipe and 1 muffler. RB replaces the muffler and the manifold/cats.

5. see 1a, the converters get replaced with the presilencer.

ps, the stock muffler gets tinny and nasty when you take the cats out, although in kind of a neat way, and its not super loud

 

Thanks! Is there a system that I can use that retains the cats but uses more up to date ones that flow better?

2 pre cats??? I thought there was just one..... Sheesh how dirty does this engine run anyways?

 

nothing off the shelf that i can think of that will use OE or updated cats.... but if you are interested, send me a PM as i have a RB presilencer that will allow you to bolt everything up to the stock back half of the exhaust if your using a RB header

 

I have the RB header and pre- silencer with stock muffler. Just put it on, and must say, dont like the sound. Loud and tinny. Is it better with another muffler?

 

full RB system on my old 12A sounded pretty nice, but I personally needed more loud...enter ported s$ 13b and straight 2" duals to RB muffler

 

This is the RB Magnaflow Borla system that I'd been running. Nice deep tone, not too loud, and the price was reasonable.

 

Put a 2" Magnapack behind the presilencer and a 2.5" Borla 1 in 2 out at the end. You'll be very pleased, I'm sure.








Running the exhaust into a larger diameter muffler lowers the tone. This I learned after buying what I did simply because it was cheaper.
To be sure, it sounds better (deeper) than the stock RB system.

 

Here's a replacement pre-silencer (or "race pipe", as they're called) a direct bolt-in replacement for the cats.

Once the four mounting nuts are loosened you can swap the pipe and cats back and forth in about an hour.

It's available at rx7.com for under $150 shipped, a fantastic poor man's alternative to the $900 RB system.

(I have the full RB system myself, it pays for itself over time, but I used the bonez race pipe for years in my 84/85 GSLs, same pipe swapped into three different cars).

You'll get a noticeable improvement in HP and MPG by eliminating the cats.

And the exhaust note is very sweet, pretty much the same as the full RB street exhaust if all your other exhaust components remain stock.

Rotary Performance | SA Exhaust

 

Good morning Ray! Yes, from my long ago experience the cat replacement pipe is 2/3 the power increase of the header system at a fraction of the price. My cobbled together system was under 500, shop costs included, a little at a time.

 

Howdy Andy, hope to see you up in the mountains at this year's Blue Ridge Rotary Run. I may even have my new Special Edition GSL project ready to roll by then.

So as a recommendation for Peter, assuming he's working on a nice FB that he plans to hold onto for a long time, may we all agree:

1) Get a cat replacement race pipe for a quick fix and immediate satisfaction.

2) Then, once the FB has earned it's keep in a couple years, spring for the full RB system.

PS, anderman, concerning your recent exhaust upgrade:

"I have the RB header and pre- silencer with stock muffler. Just put it on, and must say, dont like the sound. Loud and tinny. Is it better with another muffler?"

It shouldn't sound like that. Chances are you have a small exhaust leak someplace, either a gasket at one of the flange joints or maybe a problem with the muffler.

 

Ray, I hope to make it to the B3R. I'd love to see you driving the 'New' fb.

Yes, the cat replacement is a great bargain 1st step that I would recommend.

As to Andernamen's metallic sound, I concur with him. My experience is that changes upstream, as J9 stated, result in a tinny sound from the stock muffler. My 3 can system was built over time to eliminate exactly that, and did very well.

 

you can buy an RB header, and then make a short pipe to bolt up to whatever cat you want. the precats are there to make it all warm up more quickly, they don't do much once the thing is up to temperature