i have an 88 na and i was wondering what the best high flow cat is. i ve looked and all i could find was the bonez superflow system., but i heard they wont fit with an aftermarket header.if any one has any opinons on this system or any other sytem that would be great.

 

I have to pass emissions in Ohio, and this exhaust modification has been the best one I've done so far. I kept the stock exhaust manifold & a modified dual cat-back.

The resulting sound of the exhaust is pretty good. It has a nice low tone with the typical spinning whine of the rotary superimposed on it. It does NOT make your car sound like an oversized chainsaw like some I've heard.

http://www.rx7.com/cgi-local/2catalo...cat=4&part=300

You might want to send an e-mail or give a call to the people at rx7.com (Texas). A header may work if you just buy the Bonez Main Cat instead of the one with the presilencer attached (like I did).

I don't know what the upper RPM gains are for a header over the stock exhaust manifold. Maybe someone else can respond to that question.

Oh, and make sure you double check your 6PI system (auxillary ports), because you have a series 4 car. They may or may not work the same as before because of the change in exhaust pressure.

Good Luck

 

Mazdatrix sells cats that will bolt up to headers, but they're a little pricey. If you went with the Bonez, you just have to have a short section of pipe attached to one end of the cat so that it reaches the header.

Wouldn't be too hard for a competent welder or an exhaust shop.

 

I used to have a N/A 87 Rx7 SE. My cats got clogged so I went with Mindtrain high-flo cat. They are based in Beverly Hills CA. The good thing about this cat is it gives your car 20hp!! I installed it on mine took it to a dyno. Mods before the mindtrain cat was just a K&N replactment filter and 2.5 catback. Dyno read 178 hp after the Mindtrain cat. They are hard to find but they work great.

 

GO with Mindtrain. Their cat convertor gives your car an additional 20hp! My little SE was fast for an N/A

 

could it have been that the 20 hp increase was more because you replaced your clogged cat and less because of the header?

 

Yeah are you sure about that horsepower number? If so where did you buy the cat from? is there a web site?

 

thanks for the replys. but has anyone had experince with the bonez system?

 

best cat=no cat hehe

 

I have the bonez cat on a 88 convertible with otherwise stock exhaust system. I'm not sure about horsepower gains but it's holding up well and its a bit louder than stock when you open it up, but not by much. It's the cheapest way to pass emissions, I think.

 

any body else have opionions

 

I've never used one on a car, but I can get a good deal on carsound high-flo cats if anybody is interested.

 

I've used a Bonez cat setup for my 86 (while it was N/A) and I purchased another Bonez cat for my T2 conversion I am doing right now. With the N/A, I passed California emmissions twice. Power-wise, it seemed fine as well, although I won't boast a 20hp gain from just the cat

 

thanks everyone. ok i think ill go with the bonez cat. with a custom pipe to single side muffler. im thinking corksport though because there not to exspensive and from what ive heard there prety well made. any suggestions for a different muffler. better?

 

Catco

 

Bonez is a good cat, but i would go with the Catco will burn up, and clog after about a year. It's a cheap intermediate replacement. I would recommend www.randomtechnologies.com for something custom made specifically for the rotary. Good stuff

 

Random technology is over priced, and some forum memebers have run catcos with no problems.

 

https://www.rx7club.com/forum/showth...Bonez+superflo

https://www.rx7club.com/forum/showth...hreadid=207223

 

any opinions on a good low tone muffler

 

ive thoght about using a moroso spiral flow muffler, but i havent heard any opinions on it

 

anybody out there using a moroso muffler?

 

borla makes some real nice stuff. I use an xr-1 as a presilencer.

 

i looked at the xr-1 and there nice but im trying to save money, so another 200$ pre silencer wont work. would using the corksport muffler be a good choice?

 

i have a R.P. exhaust from rx7.com they look almost stock. tips and y pipe are a littel bigger nice sound.good price 395 for duals.i am going for the bonze super flow cat system now will let you know what i think.

 

the r.p. system is good but i dont want duals. plus i would like a muffler with a little bigger tip , like 3in. to 3.5in.