1988-1990 Nissan GTP ZX-T

Images copyright Michael J. Fuller
Text copyright Michael J. Fuller

Nissan GTP ZX-T, chassis # 8805The GTP ZX-T bodywork introduced at Portland in 1986 was a departure from the Lola 810 starting point, especially in regards to the rear wing location and position.  During wind tunnel development Yoshi Suzuka noticed that the closer the rear wing was in relation to the tunnel exits, the more effective the car’s tunnels were.  Now this isn’t to say that Yoshi Suzuka was the sole originator of this idea, certainly this was going on at other outfits at around the same time (think Tony Southgate and what he was up to at TWR).  But Suzuka methodically documented his results and scientifically came to the conclusion that the rear wing’s effect on underbody downforce was indeed substantial.

The test concluded that the wing itself was generating 1833 lbs of downforce from the car’s total of (for this test) 5408 lbs.  More importantly, the wing was influencing the generation of an additional 1575 lbs of downforce, making the wing responsible for 3408 lbs, or more than half of the car’s overall downforce!

Now without any doubts about the interaction between the rear wing and the underbody Suzuka proceeded to define the exacting location of the wing, methodically testing various positions until the sweet spot was found.

Note the prominent aluminum beam running the width of the car and integrated into the engine cover.  All the wing loads were transmitted into the engine cover through the integral rear wing endplates.
Nissan GTP ZX-T, chassis # 8805Suzuka adopted a double element rear wing, designed by Bernard Pershing, and introduced it during the ’87 season, replacing the Lola-derived single element wing.  The Pershing wing’s secondary flap's center section had a longer chord than at the tips and outboard trailing edge was chamfered as a result.  According to Suzuka, the large radius leading edge of the main element was designed to compensate for turbulent air.
Nissan GTP ZX-T, chassis #8805The GTP ZX-T's rear wing loading is divided between the two outboard endplates as well as a central pickup that locates off of the gearbox.  As the rear wing was direcltly mounted to the endplates, which were in turn bonded to the engine cover, the central mount here was only pinned so that the engine cover could be quickly removed as needed.

ęCopyright 2012, Michael J. Fuller