Up for sale is a Honda b18 manifold on a NB flange. This was welded up by Chatham CNC.

Includes custom plate that allows for a miata throttle cable bracket along with a throttle body adapter ported to run a skunk2 64mm TB. It’s removable so if you want to run a larger Honda TB you can. There is a plate welded on to utilize the factory miata intake manifold brace, which prevents cracking at the flange. The brace and hardware are included.

I picked up a few peak HP over a squaretop using this manifold on my N/A BP, but forced induction is where this manifold will shine.

$425 shipped CONUS

Going K swap so I am slowly purging my go fast BP goodies.

 

That's pretty cool! Are there any before/after dyno results comparing a stock or squaretop manifold to this one?

 

Sure thing here’s a comparison between Honda and squaretop N/A. It’s not apples to apples, I swapped intake cams too and looking back I’m thinking it’s possible the intake cam was a tooth off for the dyno. Or the new intake cam simply pushed all the power to the right.

There are a few instances in an FI application where a manifold like this clearly outperformed a squaretop. It may work well in a wilder N/A application too.