Hi I currently use a 1987 rx7 N/A as my daily. It currently has a Racing Beat cat-back exhaust system on it with the stock manifold and cats and I was wondering what would be the best option to finish my exhaust. I was looking at either the RB headers with the presilencer or the headers with a Bonez hi-flow cat. Does anyone have any experience with either of these setups or is familiar with other alternatives?

 

It think the headers with the bonez hi-flow would be your best option. Most places require some sort of cat to be road legal, especially if your area has emissions testing.. Ive ran no cats before and the exhaust coming from the back of the car gave me the dizzys a couple times hah. Besides all that from what I've heard the presilencer makes it way to quiet. The RB mufflers kill enough of the sound as is. Good tone just no volume.

 

I need to Google this bonez cat,as I do not know if it has what I am about to describe, but since you have an S4 you need to keep the back pressure tube coming off the stock cat to the Aux ports.

Other wise you will lose top end power from not having the 5/6 ports opening

 

Thanks for the replies. I've heard both options really boost the volume of the exhaust compared to stock. Now that you mention the getting dizzy, I remember what it was like driving with half my exhaust missing so I'll probably go for the cat.

Also to answer archaphil's question I read that that you'll need to fabricate a split air pipe, it even says on rx7.com's site that you'll need to do that. How exactly, I'm not sure.

 

I have an 86 gxl na with the rb true dual headers. It has the back pressure pickup tube you need for the secondary port to open. From the headers I have the rb presilencer to the rb y pipe with apexi mufflers. It is too loud for a DD imo. Here is a link so you can hear my car.

 

^I love the sound of your car but wow, that's definitely too loud for my intended use. Thanks for the reference though!

 

There is 2 other videos of my setup idleing from cold to warm, this one is WOT.

RB streetable to punched stock cat with and extended tube and factory resonator removed.. STOCK y pipe and mufflers, those are next on my agenda. I like it