Quote Originally Posted by Greg Amy View Post
Is that a trick question...?

Cam lift limitations limit maximum airflow, with the assumption that all other components would flow more with a larger cam*. Remember, in STU/L car weights are based on displacement, not on rated power using stock camshafts; short of using inlet restrictors**, it's the second-easiest way of limiting airflow and thus, ultimate power potential.

Roundy-rounders have been doing that for years, placing limits on cam and displacement. They have the added benefit of choke size on carbs, too. But in the end different engines will respond differently to the mods, and as we've seen in our favorite category with the disparity of designs there's no real easy way to predict it...

GA

* In a perfect world, the .425 cam limit would be the power limiter versus hitting throttle body, intake manifold, and/or head flow limits first. Yes, I recognize it's not a perfect assumption, but given most engines it's a pretty decent number. Witness Type R - YO! - cams versus GSR, the former having head flow rates similar to the GSR, and the limitation of the GSR intake which would not work well even with the Type R - YO! - cams - and maybe not even the .425 exhaust cams (intake is already there, and maybe actually be the basis for that chosen number, to limit the growth potential of the B18C1 engine...)

** Please...no...please let's not go there.
You hit on my point. If the rules mandate factory intake manifilds and throttle bodies, why impose a rule that drastically limits engine choices or makes you 'back-engineer' them?