Here are some photos from a guy I know who is a god of all things S30.
These are some pics of his of early efforts to 'improve' the aero characteristics of S30-series Z cars.
First shot. A 1971 factory 'Works' 240ZR race car with an FRP front panel that reduces the radiator inlet size ( I believe it was also fully ducted to the rad support panel ) and gives a separate inlet duct for the carbs. This car also sports a front 'spoiler' with brake ducts and slots for the QuickJacks used in the pits. The full-length FRP engine/trans undertray appears to be slightly damaged and is hanging down at the back.
Note that this car - like so many of the Japanese circuit race Z cars of that period - was built for
endurance races that varied from 300 to 1000km in length:
Another Works car at speed. Similar to above spec, but with outlet ducting added to the bonnet ( hood ):
A slightly clearer view of the bonnet ducting in this 'pit-in' shot:
Aftermarket race parts suppliers in Japan were soon on the case, and producing their own versions of the parts seen on the Works cars. Here's a period magazine ad from 'Scuderia Nissan' ( a race team / parts manufacturer not actually affiliated to Nissan Motor Co. ) that shows a similar front panel treatment - but this time for the S20-engined Z432. Note the carb inlet duct on the opposite side to that of the L-series engined versions:
