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From this view, you can see the galvanized steel box we built around the radiator (in the background) to keep the hot air from blowing on the driver. We also had to add a layer of styrofoam to keep the hot steel from being intolerable on the driver's right arm.
The final variation of intake air flow was this louvred door skin we added to meet the letter of the new fenders, doors and hoods rule. Surprisingly, this still seems to work fine.
Getting air into the radiator is the obvious part. Getting it out the other side is where things get tricky with an interior mounted radiator. We sawed these big holes in the rear bulkhead to give the air somewhere to go.
And these holes in the floor.
This galvanized steel panel is used to create a flat package tray under the convertible top. Remove this panel, or inexplicably cut a giant chunk out of it (I can't honestly remember why we did that) and you'll see that the fuel tank lives in a big bulge in the middle of the shelf, but the rest is just dead air space connected to the trunk. By sealing up the part you see here, and opening up the part behind our passenger's-seat-mounted radiator, we can use this space as a duct to carry hot air to the trunk.
Then we cut open this panel between the taillights, giving that hot air somewhere to go. This worked well enough that on cold days in the pits you could kick the radiator fans on and warm your hands between the taillights.
The big debate was over this opening above that mysterious channel. Some of us thought we should leave this open to let air out of the radiator. Others thought this would actually hinder airflow, as air tends to curl around the roof and actually flow forward in an effort to fill the relatively low-pressure passenger compartment. Anybody who has driven a convertible knows air is always blowing on the back of your head…
To settle this debate, we put tufts all around this area and attempted to watch them while driving. Obviously, this was impossible to see, but what we did discover was that the driver felt lots of hot air this way. Air apparently does come out of the radiator here, and then that backflow over the roof blows that hot air on the driver. In all but the coldest winter races, we run with this panel closed simply for comfort.
