I was wondering what the best high flow catalytic converter is in your opinions? Im looking into buying one but I dont know which one i should get.

 

Random Technology.

 

http://www.smb.net.au/fullsystemsmazdarx7.htm - SMB makes some quality units

 

Given the number of failures that Random's had with FDs, that's not a solid recommendation IMO.

The Bonez one from Rotary Performance (www.rx7.com) is a great hi-flow cat. Quality construction and includes the air pump tube already welded up.

 

smb is definetly best bang for the buck, its a beautifully crafted piece. If I ever put a cat on the car again it will be that one.

 

random technoogies. I have one and the car runs very smooth. It adds a low growling sound. Very nice sound and great quality.

 

SMB (also has airpump tube). I've been running mine without airpump for quite some time now - no issues.

 

My 2nd one:

Bönez 3" Stainless Steel Main Converter:
The exhaust heat produced by a rotary engine is much higher than that of a conventional piston engine. This created quite a problem for us in our quest for an aftermarket catalytic converter that could perform up to our demanding expectations. After trying nearly every aftermarket cat available, we found that they all use a standard type suspension material around the ceramic converter brick. This material is not designed to endure the tremendous heat of the rotary exhaust which causes it to fail prematurely. Once the suspension material has overheated and broken down, the ceramic converter brick is left loose to rattle inside the case. The loose ceramic brick eventually causes its own self destruction, increased backpressure, and excessive noise.
After extensive research and development, we are proud to present the Bönez catalytic converter. Unlike other aftermarket catalytic converters, the Bönez unit uses a stainless steel mesh suspension element that surrounds the large, high flowing converter brick. This suspension element is built to withstand extreme termperature demands, and provide many miles of dependable performance. The case is also constructed of stainless steel for better durability, and incorporates a unique design which causes the inlet exhaust gases to spread evenly over the brick for better flow, improved efficiency, longer life, and reduced noise. This item fits between your stock precat or performance downpipe and will bolt directly to the stock catback system or any other aftermarket catback system. The Bönez kit also is much lighter than the stock unit it replaces and noise levels are only slightly increased. Please also note that the oxygen supply tube from the air pump is still retained, making this system 100% bolt on.
Bönez 3" Stainless Steel Main Converter
Price: $495.00 Sale: $420.75
Rotary Peformance Online
(972) 530-3335

Good Luck!!!

 

The best IMO is home made!!! Get a cheap used or ebay midpipe, buy a universal 4" 200cell metal core high flow cat with 3" inlet/outlet and go to any exhaust shop and have it welded in place. Do it while the midpipe is installed in the car to make sure everything fits correctly.

Some exhaust shops won't touch cat converters at least in my area so I ended up going to a guy that makes custom racecar and harley exhausts. I used a 200 cell 4" metal core and a Magnaflow resonator and even got and airpump pipe in place! Total cost was about $300, it'll be cheaper without a resonator. It works perfectly!

 

Several people have experienced failures with those new Metallit cats on FDs....I think the jury is still out on these things for turboed rotary use.

 

Thanks for all the help guys, I think I'll try to look into the Bonez cat offered by rotary performance.

 

Save yourself $100

http://www.rx7store.net/product_p/highflowfd3s.htm

 

Even with the SMB cores w/ the air pump attatchment?

 

I read about a SMB metal cat failing on an FD, but has anyone experienced failure with a Knightsports Metalit cat??? Anyone have the pro-200 version?

 

I got a big cat from Carsound/magnaflow with the air tube attachment and welded it into an existing midpipe, and connected the airtube to my airpump via a custom setup. I have had no issues with it, and passed emissions with flying colors.

 

No mention of the Pettit hi-flow cat? I've had mine for 2 years, works well, and I still pass Georgia emissions. Also has the inlet for the air pump.

 

It seems like the Bonez is the only one that has proven durability. I would like to hear from anyone that has used another unit for more than 5 years, or 50,000 miles.

 

I have a Bonez and chose it because it was the only one made specifically for the FD. I have heard that heat will tear up the others, since they are universal cats made for many different cars.

On a side not, are you keeping your cat because you want it quieter, or so it doesn't smell? Because if it is just for the smell, you may want to look into a metal substrate cat welded into a midpipe. I have heard it gives the same performance as a plain midpipe, but cleans the exhaust still so it doesn't stink, however, it will still be as loud as a midpipe.

 

Jason,

How is your cat same as/different from the Bonez cat? Certainly if it is the same saving a $100 seems prudent.

Thanks,
Justin Wade

 

the SMB is FD specific - SMB developed the SP exhaust system and assisted with the bathurst-winning race cars.

as for failures - the only one I heard was due to someone running too rich. There's a fair group of us over at ausrotary running them, with no issues as yet.