Rad Modification

[Sydney]

Hi all,

EJ20 in late bay with rad and scoop between the chassis rails (fans on top).

After initial overheating issues about 8 years ago I bolted an additional intake ramp to the chassis rails in front of my scoop, effectively doubling its frontal area. The intake ramp is relatively flimsy (sacrificial) and droops a little at speed, a bit like the Red Bull rear wing. Coolant temperatures are now all good during cruise, only rising towards 90 degC on long climbs.

The top of the rad is open on all sides, allowing air flow over the top of the rad and removal of expelled hot air during cruise. However the temperature can rise when static in traffic for long spells, as it does on all cars. When the fans kick in some of the expelled hot air recirculates back into the scoop.

Not really wishing to fix something that ain’t broke, I was contemplating blocking off the gap between the chassis rails above the rad to prevent the hot air recirculating when stationary. However, I don’t know if this might reduce rad efficiency at cruise by reducing the removal of hot air from the top of the rad, or if it might in fact improve its efficiency by reducing the pressure above the rad and increasing the air flow through it. I suspect the former so I have not tried it yet.

There is another reason for doing this though. I could then draw hot air from above the rad to heat the cab in winter. My heater matrix is rubbish.

Has anyone tried this approach or got any views on it?