What are the differences in the Catalytic Converter assemblies between 81-82, and 83-85? Pictures would be nice too.

Thanks,


-Crispin

 

this should help:
http://www.blackdragonauto.com/icata....aspx?Page=127

 

Ahhh.. I forgot to look at BDA.
I'm guessing the only difference is that 81-83 has 2 cats and 84-85 has 3?.. I wonder which flows better. And which is better for emissions.

 

yes 81-83 has 2 cats and 84-85 has 3. also 81-82 has 2 pipes into the muffler and 83-85 has only one.

I would think 84-85 have better emissions and 81-83 have better flow. If you can get away with it, I would look into the Bönez street midpipe. I don't think it will help emisions but it will flow better.

http://www.rx7.com/store/rx7/saexhaust.html

 

I already have one, I've had so many different exhausts it's not even funny. From headers, to different mufflers. Etc, etc..
Right now I'm running a 'modified' exhaust manifold to the Rotary Performance Race pipe and then to a 81-82 connecting pipe and muffler.. So far this is the setup I like the most but I'm moving and I need to pass emissions. Also wouldn't mind making the car a little quieter so.

 

the 81-83 had a pellet type main cat, these SUCK. they don't clean the air OR flow well.

the 84-85 system is cleaner and probably flows better too

 

Huh.. Glad you told me that before I went and picked up a 81-83 assembly.
What is a pellet type cat anyways?

 

I didn't know that

 

do you have emission testing in your state?
I mean why not get a high flow cat if you dont have emission testing?

 

Pellet-type catalytic converter
The first type of automotive catalytic converter, introduced in the USA in 1975. It consisted basically of a sheet steel catalyst container surrounded by thermal insulation and a sheet steel outer shell. The catalyst container was fitted with one or two beds of ceramic pebbles (pellets) coated with a catalyst. This type of catalytic converter suffered from poor service life due to vibration-induced attrition of the catalytic coating; this also produced additional particulate emissions and the pellet bed caused high exhaust back pressure, resulting in poor engine performance. Pellet-type catalytic converters have been superseded by monolithic converters

 

I'm moving to NC. Would rather not spend the money and time on a nice high flow cat, welding it on and such and then find out I'm going to get tested.. And have to drive my car illegaly; etc, etc..
Trying to make a smart decision.