Hustler,

I was really close to doing a port and polish at a very reputable machine shop but for my application on my Subaru i was no where near the need of spending the money for the work because i would have out flowed my turbo. It does see great gains though, if you are at the right point in your build. I found an article specific to Miata's that you might find interesting if it isn't old news.

http://www.enginebuildermag.com/Arti...t_imports.aspx

This should help flow your 2860 a little more especially paired with a nice set of kelfords...

 

I should have provided more detail. I'm not too interested in port work, I'm more interested in chamber work. The link I posted is from a company most people never hear of, but who make many engines for cars we see on TV, then let the manufacturer call it their own. Supposedly they've done a 250hp Miata motor and they've done several 400hp NA s2k motors running **** like 17:1 compression ratios with wild chamber, porting, and custom piston work.

My build is done. The only way I'm going through this again is to build another motor in a few years when this one is worn out, but judging from the other supercharged built motors that came from the same shot, I have another decade to go.