I have been contemplating replacing my radiator with an aluminum one.
When i read the 2016 rules, it says:
14.10 ENGINE AND DRIVETRAIN
L. Engine cooling radiators may be replaced with alternate parts subject to the following restrictions:
1. Radiator core dimensions (width, height, thickness) cannot be smaller than the standard part.
2. Radiator must mount to OE radiator mounts.
3. Fluid capacity and dry weight of the radiator must be no less than that of the standard part. Installation of an alternate radiator may serve no other purpose (e.g., to allow a cold air intake passage).
The problem is that it seems impossible to find capacity and dry weight of either the OEM or possible Aluminum replacements (Mishimoto, Amazon/Ebay "specials", etc...). Perhaps my google-fu is lacking...
The SCCA Forum search sucks, and most of the other forum posts are related to the pre-2016 ruleset.
And you don't know sucky brakes until you've owned an EF Civic... That's teh speed secretz: no brakes.