Yes, they supress the sound even more.

Carlos

 

Some of you already mentioned the Works and the ultimate racing 3"HFC. I do have both and can't find absolutely any phisycal differences. They weight the same, they look the same, everything is the same. I never counted how many holes there are in the honeycomb internal mesh though.

As far as I am aware, Works offered the first true 3" HFC that retained the stock flanges. This make their cat very desirable. Other vendors were still offering generic 3"HFC that had to be welded..

Carlos

 

what does the cel count represent?

 

The Ultimate racing (which I had) and the Works are ceramic cores. Ceramic niether flows as much or is durable as a metallic core.

Random and the version Cobb sells are metallic. Ceramic flows around 540cfm and the metal flows around 600cfm.

 

UR. Had it since 500 miles.
3+ years 47K miles and can still trap 112mph just 2 weeks ago.
.

 

I had an Ultimate Racing 3' cat on my Evo. Worked like a charm. I've replaced it with a test pipe now. Im willing to sell it at a very reasonable price. Im from Cali orginally so I know about smog (PITA!). PM if interested.

 

SS RX7 r2

PM me about one of those cores if you still have some...

 

The lesser the holes the more flow. If I am not mistaking the cel counts are referred as the holes.

Carlos

 

I live in CA

and test pipe FTW!!