It seems the general concensus for dealing with the N/A Exhaust diffuser is either leave it alone, replace it with a turbo, or take it out entirely. Some have talked about grinding it down but then said it isn't pratical because of the man hours it takes to remove the hardened steel.
Well, I wanted better flow and I was to cheap to buy a turbo diffuser so I tried grinding it this afternoon. I cut a notch along the bottom front piece (the section that angles down) with a pneumatic cut off tool and then used vice grips to bend it back and forth until it broke off. From there I just used a grinding stone on a dremel to smooth it out. Not included the welding it took took to remove the pins, I'd say I did both in about 2.5 hours.



So there you have it 2.5 hours for .025 Horsepower...

I included a picture but I'm not sure if I uploaded it right.
Brian

 

Looks good. Not quite as nice as turbo sleeves, but a hell of a lot better than stock.

 

Anyone have a picture of what this looks like pre-rx7tuner?

 

This is from the Mazdatrix Website. N/A on the left of each picture, Turbo on the right.

Brian

 

2.5 hours?! Did you use a Dremel? Takes about 10 minutes with a die grinder.

 

I used a dremel. By the time I was finished I was using gloves because the dremel motor was so hot! Maybe a die grinder would be a good investment...

 

Electric die grinders are pretty cheap. Mine's an industrial model so it cost several hundred but it uses a 3/4 horse motor...I think Harbor Freight has the made in China version for about $39.

 

Yep, harbor freight is great for cheap tools. I'm kicking myself for not getting one at the grand opening sale. I did get a brand new engine hoist for 90 bucks, though, so its not all bad.