I think they're talking about the 12a Y plate with the tall runners. They're almost the same size as cosmo runners and you can port the y plate huge.

 

And if you have an intake manifold that has a tight pinch right before the port, a super tall runner will hurt flow.

I haven't played much (well, at all) with 13B-RE engines, but don't they have the same angled runners that an FD has? That helps the situation considerably.

Best would be a manifold that is straight-shot with no vertical bends at all, but there's this silly problem with having to fit the engine in an engine bay. Mid-engine, rear-engine, or cars without strut towers wouldn't have this problem.

I've heard of people swapping Mustang II suspensions into older Fords just so they could get rid of the strut towers. (I looked into it, it would be stupid hard for an RX-7)

 

Ah, so that helps... just a cosmo engine with S5 NA rotors then?

 

..............is Awesome lots of knowledge to be attained here for new rotary enthusiast.

 

So I'm working on my na and I was thinking of putting it on a haltech so I can run an ITB setup. I'd go with the racing beat road race exhaust that runs full dual, no collector. Thoughts?

 

This is pretty much the setup I have on my FC race car. Street-ported s4 w/ large exhaust ports. I have 850cc primaries and 1000cc secondaries on a Fuji ITB. EMS is a Haltech e6x. I have an RB header w/ collector running straight through to a Magnaflow "muffler". I turned 179 rwhp and plan for more w/ a AEM Twin Power CDI I have yet to install. I hope you are not putting this on the street, however, as the exhaust noise is fairly extreme.

 

Does anyone know what a 13B large stage II (extend port ) has the potential to make?

 

What size ITB do you have?

 

Same as your's--47mm.