Isn't there a quicktime sfi bell housing to bolt the T56 to the LE5?

 

Other than the sound, is there any other advantage with the 1-3, 2-4 matching of the headers? Seems wrong to me.

 

I also couldn't initially get over this when I started shopping for an Ecotec Miata header. But, when I researched it, I found that some of the most highly developed race headers for S2000 and K-series are odd fire pairing--they call it "sequential" pairing. It seems to me that you need long, large diameter primaries and short, large diameter secondaries to make it work. The folks at Shenzhen Fashion Super Quality Stainless could have simplified their design and made it 1-2, 3-4 paring, as there is no difference from 1-3, 2-4 pairing.

I eventually went with the 1320 Performance Polaris Slingshot shorty header because it has 1.75" primaries and seems to be a higher quality piece. I don't think my $500 engine with stock cams is going to care much.

 

This?
1320 Performance Polaris slingshot header

How do the dyno numbers supposedly compare to a 4-2-1?

 

It's less about dyno numbers than it is about finding something that can be made to somewhat fit after many hours of swearing and dollars. To say that the space is tight would be an egregious understatement.

 

Yes, that one. The Ecotec Miata guys consider it part of their 200 rwhp LE5 recipe, along with an 06-07 LE5 intake manifold, a ported throttle body, and a 3 foot long intake tube (filter to throttle). The Manzo/M2/Shenzhen Fashion Stainless 1.625 OD primaries are just too small for a 2.4L engine at 220 hp and it's no stretch that a 1.75 OD primary shorty header makes more power. Considering the stock cam engine won't be terribly sensitive to the supreme scavenging of long tubes, the packaging advantages of the shorty become worthwhile.