B16A ITB sizing questions

[007]

Hey guys,

I've been offered a set of 40mm throttle bodies etc, without a manifold, to go onto my B16A. One thing i just can't find is the port sizes for a std intake manifold. The reason I wanted that info is the more commercially available kits seem to have either 45,48 or 50mm throttle bores. So I wonder if I take this kit will I be reducing airflow? Because what I planned was to get another manifold and cut it up then tig the new tb's to that. The company that made the tb's has a manifold adaptor plate for $650 I think, seems a bit steep to me. Anyone got any technical input on CFM calculations?

Thanks in advance boys,
George.

[EfiOz]

It's a bit small for a B16. This would limit outright power to about 200HP. 45mm should let up to 260 which is plenty.

You'll get some good mid range with the small TB's though.