I am thinking about opening up the exhaust on my stock 89 GXL. I do not intend on doing anything wild I just want to prevent the pre-cat from clogging main cat as my 7 is my daily driver. I would like to know what everyone things about the differences between using a RB downpipe or a RB header. Have to keep it at a reasonable street driving volume. Also I plan to use a Bonez cat to go with the header or downpipe in order to replace the main cat.

 

Racing Beat says they're about the same for fuel injected vehicles; the header is only better with a carb. The downpipe is cheaper and less noisy too. Both replace the main cat with a presilencer IIRC. Most of the gains on both come from eliminating the cat so you might as well get the Bonez cat by itself and call it a day. I think both options replace both the main cat and pre cat, and one option gives you a new precat the other doesn't (straight pipe or presilencer I think). Or if you don't believe me at least get the downpipe rather than the expensive and noisy header. It says it's about as good right on the RB website (again, unless you get a carb).

Since you have an 89+ as long as you keep your air pump you'll be in good shape from there.

 

A header will offer slightly better performance, but at the cost of added noise. A cat or silencer will help cut this down. You also can't bolt an RB downpipe or header to a stock cat or anything other companies make that directly replaces it. RB's stuff is all made 3" shorter to make room for their presilencers, which are longer than the stock main cat.

 

a header bolts to the engine. a downpipe bolts to the turbo.

 

Noise wise you'll be fine either way.
My friend has an S4 vert with the "downpipe"/presilencer and a Borla catback - I have RB headers/presilencer/cat-back.
My car's actually a little quieter.. [also, if you're thinking about a cat-back the RB one is awesome IMO]

 

+1

RB might be confusing it's customers by using the wrong terms.?!

 

Well they actually call them "Cat Replacement Pipes" and "Down Pipes" [title vs picture caption] - so yes, quite confusing, in fact they even call [Turbo] Down Pipes "Cat Replacement Pipes" in the title of the link.

To me it seems that "Down Pipe" is the closet to a normal term for that tube unless you want to get really specific like "NA Pre-cat Replacement Pipe", but since the length isn't *quite* that of just the precat section it's more like "Racing Beat NA Manifold-Presilencer Pipe."

 

Yes, RB calls their precat replacement pipe a "downpipe". It bolts to the exhaust manifold on one end, and the other end is intended for use with their presilencer. I think they've just started packaging the two.

 

I've tried all the options. on my new n/a i'm going to have an exhaust shop make a downpipe. its just one crush bend and a couple flanges. you get a couple more horses with the header, but it's too damn loud.

 

I have a precat still but straight through from there, its loud as a jet.
I want to get headers though and install my own presilencer of sorts and then all will be fine.
More horses and wont be much louder than a f-16.

 

If you consider weight,the cast iron Stock N/A exhaust manifold can hold a tugboat in place if used for a boat anchor!.(about 30 pounds,at least).Then factor in your pipe going to the cat.
The aftermarket header would reduce weight by Half,at least.
I started off N/A and the first purchase I went after was an Aftermarket Exhaust system.
I hated the "droning Bee" sound of the stick exhaust.
The RB or even pacesetter header really makes the car sounds alive.Just don't get the header and attach it to stock cans..or the Bees come back!

 

wrapped RB header with bonez cat ending with a set of RB rev TII cans

 

Thanks everyone I think that I am going go with the header and bonez cat combo but I would like to know how much louder it is than the stock set-up. I have had some experience with vehicles that had headers installed, but none of them were rotaries how the volume increase will compare.