Im going with a begi "s" with an sr20 t25, im looking to get around 200rwhp and ill be using a SS separated gases dp from begi. For the rest of my exhaust i would obviously like to continue 3 inch exit from the DP back. Ill be doing a custom cat back to an already acquired magnflow 3 inch muffler. As for cats im thinking of using a magnaflow cat. This one here seams very reasonably priced, although im unsure if its the right dimensions.

https://935motorsports.com/catalog/p...roducts_id=742

Anyone have any experience with this cat?

Opinions/comments/suggestions. And a test pipe is out of the question due to smog laws.

 

You could do what I'm doing, which is the DP swaged to 3", a 3" test pipe, and 3" exhaust. Then some cheap **** cat that gets bolted in 1x per year on emissions day.

 

I've had a magnaflow cat in my car for about 4 years. I've passed emissions with it multiple times and it has survived my learning experiences on spark and fuel tuning in megasquirt. I wouldn't hesitate to buy another cat from them.

 

2.75" to 3" Ca...test pipe.

 

I prefer Test over Cats any day. I LOVE FREE FLOW


^ I like that test pipe where can i get one of those

 

Jason @ Enthuza made it for me. $70 IIRC.

 

dam good deal! IIRC?
couldn't figure it out

 

I have a 3" catco cat for sale... just buy it and have a shop weld it in with flanges ie: testpipe swappable style....

 

If I Remember Correctly.
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^thanks

 

Fixed that for you.

Grassroots Motorsports just did a test on an n/a miata using various cats and test pipes and found that a decent high flow cat was not noticably different than a test pipe. the stock cat was the suck though.

 

Meh, my friends turbo 2.2l just passed emissions with a 3.5in exhaust and no cat.

 

You picked the right forum to ask about cats. That's for sure. Everyone on here is obsessed with them. I think every one here has one. Some have several!

 

there's passing emissions and then there's not blatantly polluting within the loose emissions guidelines

 

This Spring has been too cold, i think everyone should remove their cats.

 

I talked to Corky about having them make the SG downpipe with a 3" outlet, and he said it could be done.

C

 

He can, he is building one for me. He starts with the 2.75" and swages it twice, 1/8" per time, to a 3" exit. Charge is $30 on top of the stainless pipe.

 

Im doing the same, i guess i could go with a test pipe and swap it in as needed, but i also like the idea of not polluting the air too. Ide like to be as legal as possible and not get hassled by the local law if they decide to pull me over.

 

If you want an actual cat for not-polluting reasons, look for a 200 cell per inch full metal substrate cat.

Expensive and difficult to find, but proven to flow much better than magnaflow's cats.

 

GRM mag just had a miata cat test. Though they tested the smaller 2" and 2.25" pipes. Like deliverator suggested the round "spun cat" with metal substrate beat all the others in flow. It actually outflowed the test pipe near redline by 1 hp. Though that may be due to tuning.

Oh they are more durable in regards to heat and vibration too

And magnaflow does offer a metal cat which is what they were testing. I'm sure any brand would be fine.