Best bang for the buck yet!
 

And I do mean BANG!

There are many similar setups on here making 220-250whp and I like to fins my missing 20-50 hp (made 200). I have a 2.5" mandrel exhaust with straight through muffler and a 3" hi flow cat on there. The other day I removed the cat and BANG BANG BANG its gone, installed the pipe back and wow what an improvement. Not noticeably louder and but the butt dyno tell me we picked up some major power in the 5-7K range. Sweet!

So off with that tree hugger green planet crap and on with the HP!!!

Next going to address the turbo intake piping, think there some power to be had there too...I will report back.

Need link to Drag-Day... more legit if wife sees actual advertising.
And even with my 185's... I'm going to crush you:fawk:... and simultaneously hope I don't need a flatbed to get it home... 6"dif FTL:bang:

have fun with more hurricanes:ugh2:

Needs more 3inch exhaust.

Sam......

https://www.miataturbo.net/forum/showthread.php?t=25263

I'm pretty happy with my cat. My exhaust is a 2.5" enthuza with the same size high flow cat. I'm making pretty good numbers at reasonable pressure. Maybe you had a bad cat? Not sure the expansion from a 2.5" to a 3" cat to a 2.5" pipe was helping either. I thought the idea was to keep the flow speed up through the cat. The neck expansion would slow flow and the back down would be a restriction.

Got me. It did not look clogged and it looked less clogged after I smashed it out of there. Maybe your on to something with the pipe transition, I'll try removing the down pipe completely for a run at the track next month.

Another thing, think its going to need any tweeking on the AF map now?