i’m very bored and i would like to share my nerd knowledge
2004: This was the last year the NSX ran on its first platform from 1996, before it was changed to the one based off the NSX-R GT.
2005: There were actually 2 versions of this car, both based off the new chassis. Phase 1 of the 2005 Super GT NSX had a twin turbocharged, 3.0L C30A V6 from the original NA1 NSX. It also kept most of the old front facia features, and kept the side intakes too, albeit slightly restricted later on. It also had a larger spoiler, which was higher but shorter.
2005 Phase 2: Mid-season, the NSX recieved an overhaul. Since the twin turbos and the smaller displacement were causing some problems with the officials and reliability, they switched to a simpler 3.2L C32B naturally aspirated one from the NA2. They also removed the huge intakes due to restrictions thanks to the rule change, and the ground effect scraping aero wasn’t making any of the officials happy so that was changed to indented stepped floors. Epson Nakajima also switched to Dunlop tires from Bridgestone.
2006:
Not much, and yet at the same time a lot was changed from the 2005 NSX-GT. The front facia was slightly updated, with a larger grille being added to accomodate smaller lights underneath the lip of the intake. The hood also recieved an extra pair of grilles near the fenders, and the spoiler was lengthened.
2007:
Not much was changed for the 2007 season, and yet it was much more successful than the 2006 version. Stepped floors were added in 2007 to prevent a ground effect car from existing (cough cough 2005 nsx phase 1 cough cough) and to reduce the speeds, and yet the NSX-GT was unaffected due to its MR layout. The refuelling cap was moved from the right headlight down towards the bumper (exempting Kunimitsu Racing) and the front grille was widened but shortened and the lights under the lip were moved down with it (except REAL Rolling Stone Racing, Takata Dome, and Kunimitsu Racing, who cut a slit out for the lights above the grille). The rear wing was also lengthened even more, and rear vents were added at the bottom to complete the rear arch. Finally, grilles were added near the canards (except Nakajima Epson Racing).
2008: Not much was changed from 2007. The officials decided to add mandatory 40kg weight ballasts to the NSX because apparently nothing was stopping the NSX, and downsized its engine. To combat this, Honda bent in the supports of the front arch, bent in the rear vents on the rear arch, made the rearview mirrors more aerodynamic and removed the bumper lights alltogether (except for Takata Dome, REAL Racing, and Kunimitsu Racing). Even then, it didn’t save the Honda teams from scoring low, with Takata Dome scoring the highest overall standing of 5th. (couldn’t find a decent picture of the 2008 car irl so i used the gt7 epson pic)
2009: The last of the NA1 NSX-GTs. Unfortunately, the regulations banned MR cars in 2009, but since Honda obviously was not ready with its HSV-010 GT the officials let Honda off with using it, albeit with a heavier weight penalty and an even more downsized engine. The wing was made more curved back and was even smaller (later used on the HSV), the front facia was tweaked with a larger grille but with its front canards removed, and the exhausts rerouted into one singular pipe (also used with the HSV). The stopgap NSX failed with all 5 teams - exept for ARTA, who won the final race of the season in a blaze of glory and took 2nd in the standings.
