My 1987 300D
My 1987 300D
Water has a high specific heat and the fins of the radiators hold a relatively large amount of thermal energy for the surface area they provide when compared to an air/air IC. Because of this, the radiators tend to work more like a heat sink than an air/air IC. A heat sink works best when it's big.
Were I to install an A/W IC, I'd give a modified P-flow condenser a shot. They're thin, you can get one that fills out almost all the space in front of the condenser, you could still have room for electric cooling fans in front and the fins hold a small amount of water relative to the surface area.
The only caveat I can think of is that the end tanks of the P-flow condensers have baffles to direct the refrigerant through the condenser like this
This would cause a restriction. Removing the baffles would slow the water down and increase flow capability. This would take some brazing skills.
SCCA has a rule against a/w IC's. Obviously O.E. equipped cars get a pass. If your local tech inspector wants to give you shit about it, he can.