I searched, but couldn't find anything about Magnaflow's converters, just mufflers.

I came across these from Summit. They're 2 individually sold units to replace the precats and main converter.

They come out to be almost the same price as the much praised Bonez system, so does anyone know if they are comparable?

 

From the description they are just comparable to a new factory cat, so far as flow, etc.

As for quality, I run a 3" magnaflow cat on my 7 and have another here waiting to be used for another project... as to say I think the quality is great that I think I'll stick with magnaflow.

Performance, I would get the specs for cells per square inch of each (someone in customer service should know) and get the one that has more... if it's the same get the less expensive set.

 

Check out my thread. I ended up getting a bonez race piep for my 83 GSL and the race pipe is awesome, sounds amazing and more power. https://www.rx7club.com/1st-generation-specific-1979-1985-18/bonez-cat-replacement-pipe-cat-coneverter-651623/

 

A brand name cat is usually better than the generic universal cats you see on Ebay and local muffler shops.
Id recommend going with a large core,if you get anything but a rotary specific cat.That way it can better handle the heat and high concentration of pollutants that the rotary spits out.

Years ago,SportCompact Magazine refurbised an 83' GS with that same philosophy.They ran a RB header and muffler,then installed the biggest Random Tech catylist thay could source(it was the same length as a RB presilencer).
Their HC levels dropped from about 1500PPM, to 4PPM........it held together for a couple years until the project car was stolen/wrecked/whatever happened to it, all those years ago.
Granted,their setup would not have passed a visual smog inspection with the headers,but it shows that a non-rotary specific cat can do the job.Im sure the cheap cats can get you by the test too,but their long term durability is probably questionable.

FWIW,my 3" Bonez cat has endured over 6 years of boosting and beating behind my TII engines.It still passes CA smog with ease(just passed last week)....even with a streetport engine.That durability, far outweighs the cost.

 

I've been following that thread. I want to keep cats on my car, and so far the Bonez one seems like the best buy.

Without looking up the sizes, the biggest difference I see so far is that the Bonez one has a presilencer in place of the precats, while the Magnaflow looks like it's another converter.

 

Well, at rx7.com theres a bonez race pipe(no cat) system and the bonez cat system(with cats). I would definately go with bonez either way cause there quality is great and the part is built for the heat of the rotary engine.