Originally Posted by
Ba82Ep3
Good call Q. Its not so much the combustion chambers, even though there is a difference there, its the runner design. The k24a2 head works best with its longer runner manifold to produce TQ and midrange. The k24a2 head flows less than the k20a2 head, and the k24a1 head flows the best up to 7krpm. The BC stg2 cams would work better with his RBC and either a k20a2 or k24a1 head. Or... reinstall the k24a2 cams for the k24a2 head and the RBC... and retune (of course).
If the BC stg2 profiles are the same as when i had them... then he might do better going with a PRC mani over the RBC too. It depends though... i didnt have an RBC to test back then. The TQ curve looks a little weak from 3 to 6krpm... could be cam angle or the fact the tuner didnt do a lot of work with ignition advance. Its hard to say.