Cybaster

Hello,

I need to pass smog soon and i am in need of a GOOD cat
what should I use, what are you guys using in your FCs?

if possible hopefully under 150 dollars or so, but if it can't i don't mind either
also is it necessary for a HI-Flow cat? or a normal one would work?

and should i just mount the stock airpump, let the belt drive it and have it pump air into the cat without the ACV? (cuz the ACV is blocked off and i am too lazy to install it... and my electric pump blew a 30amp fuse, so don't know what's up with that....)

what do u recommend doing for passing?

car: 1989 TII stock turbo stock IC

Jonathan

Tofuball

Jegs sells a hi-flow MagnaFlow cat for $99 that I use

Cybaster

can the magnaflow handle the temps of a rotary though? cuz i bought a catco universal (not highflow) didn't pass, and i smelled exhaust (the bad kind) after like a day.....

neofreak

I've had good luck with the Bonez cat from rx7.com, I've successfully used it to pass smog.

It's just sitting in my garage right now so if you're interested, I'll sell it for $150.

Tofuball

Catcos are garbage.

My magnaflow is still going strong.

jackhild59

iTrader: (7)

Maybe so, but they are made by the same company. They advertise very similar features. I don't know what the actual difference is.

Before you buy another cat, make sure your car is running right. If it is not running right, no cat will hold up. The ceramic brick will actually melt and bits of it will drop of into the exhaust stream ending up in your mufflers. Rotary Performace in Dallas told me that a regular cat, whatever that is, will last about 2 years and that even a specialty cat like Bonez will last 4 years maximum on a rotary engine.

I have been told by other local experts that all modern cats with a ceramic brick are considered 'high-flow' in the industry. They also tell me that what you need for a rotary is high capacity,ie a converter that has large size ceramic bricks. In absence of actual techical data on the various models, you choose a converter rated for an extra large piston engine. A larger case width and length is preferred to a smaller one. That creates two advantages:

1.) the catalytic action is spread out over a larger surface area thereby yielding a lower temperature across the surface of the brick. It is the high temperature that deteriorates the catalyst and brick, so lower is better.

2.) as the converter deteriorates with age there is a larger reserve of the rare-metal on the ceramic brick. The converter is effective for a longer period of time before decline in efficiency occurs.



When I smogged my car I got into the paper catalogue at Autozone. I looked for the group with largest rated engine with a 2.5" diameter, 3 way with air. Then I chose the longest and widest cat they had that would fit. It cost bout $115 or 120 bucks. The Autozone part number is 38734. 2-1/2" inlet and outlet.

https://www.rx7club.com/showthread.p...2&page=1&pp=15

Good luck.