Sup all, i searched & would like your opinions:

So there are 6 vendors with high flow cats that i know of:

1) RX7store/Pettit
2) N-Tech
3) Gottham Racing
4) Shane Racing
5) RX7.com/Bonez
6) Peter Farrel

(The prices vary from $299 to $595)

I know that for downpipes when this question is asked, the normal response is: "mostly all downpipes are same, its just a pipe, hks is mild steel has bend for RHD, some require removal of studs/harder to install."

Now regarding high flow cats, is there more of a design difference from each vendor than when producing a downpipe? Or are 'high flow cats' basically all the same as well?

How about installations, i read that n-tech requires your own custom piping for fitament to the air-pump, anyone able to concur? Notes on fitament/performance for other vendors?

Thanks!
Edgardo

Closest thread i found regarding high flow cats:
https://www.rx7club.com/forum/showth...hreadid=163547

 

Check these threads:

https://www.rx7club.com/forum/showth...hreadid=128667

https://www.rx7club.com/forum/showth...threadid=90067


Here's a quote from one of the threads:

 

Ill start by saying random makes perhaps the worst fitting products I have ever seen and they dont pass emmisions in most states... Its a true PIECE OF ****! and the factory doesnt help you once you fail emissions.. dont ask how I know!

 

Thanks Mahjik, your searching skills truly own me
BTW: Wish i found those before (I searched " "High Flow Cat" ")

 

No problem. I only know a lot of the threads because I've usually posted in them. IMO, get the Bonez. It will cost a little more than the rest but you won't have any fitment or other problems.

 

I've used the Random Cat' on my Honda and it lasted a few years. Well the first one lasted afew days because of a bad distributor and the cat was burning alot of fuel and glowed like a charcoal. I haven't tried it on my Mazda but they are bolt on kits.

If you don't mind welding, you can get a DynoMax Cat' or A Magnaflow Cat' , maybe Xtremeflow Cat' but never tired them though.

 

I've had my N-tech HF Cat for over a year w/o problems. Nicely constructed(SS) And it flows really well over stock cats. That's all I can say.

 

Any cat other than stock won't last long. Why? Because they are made for piston engined vehicles with much lower exhaust temps. This is why fiberglass mufflers last about as long as a hotdog on the end of a blow torch. The hi flow cats are lasting about 10,000 miles. We see this on the dyno as the car drops power slowly over 10-20000 miles.

 

I agree. I have the N-Tech Hi-Flow and it has worked very well. I have no had it for a year yet but it has performed great so far. I will let you know how it looks inside when I change it out for the stock cat when emissions time comes around.

 

I don't think that's entirely true. A normal cat won't last long, but the ones he mentioned are RX-7 specific and should be designed for rotaries (thus the higher prices). I had the Bonez and liked it (other than the way it changed the exhaust sound). It bolted right up and everything fit perfectly. Ultimately ditched it for a resonated midpipe, though.