Radiator perpendicularity to airflow, how important is it? Options

[bondo]

I'm working on radiator placement, and wondering if it's super important to mount it vertical. I know tilted radiators have bene done in 914s before, but they're usually very large radiators that wouldn't fit if standing straight up. It seems like some angle off perpendicular might improve cooling by introducing turbulence within the radiator? Too much and obviously there'd be a disadvantage. Do any manufactured watercooled cars have a tilted radiator? Seems to me I saw an RX-7 once that did. I know that the intercoooler on our WRX is pointed nearly straight up (with a scoop directing air downwards into it) and way more bugs hit the back half than the front, presumably meaning most of the air does too.

I figure that at worst I'd lose some effectiveness at cruise, because if the car is not moving, there is no airflow to be perpendicular to. Do most 914 V8s that have cooling problems have them at cruise or at idle?

[Rough_Rider]

Lotus Elises's & Exige's Both Mk1 & Mk2 variants use sloping radiators. They also have large ducting above the rad to extract the air over the car.

Many sportscars are setup like this. Enzo, McLaren F1, TVR's, plus DTM machines & various touring cars.

Getting sufficient airflow is the key, so think about ducting to & away. Mount some electric fans on the backside. Do a ton of research.

FYI i did something similar with a oil cooler on a Corrado, just used a slightly larger cooler.