2 replies to this topic

[bartez1000]

To my understanding, JGTC adopted GT300 and GT500 classes starting from 1996 season. 300 and 500 were meant to indicate maximum horsepower of cars in classes. This distraction carried of after rename to SuperGT. However, sometime in last 20 years horsepower limitation vanished, and currently GT300 cars are similar to GT3 with 500hp engines, and GT500 similar to DTM. When and how this change happened? Was there a time when GT300 cars had 300hp? Do you know any details or articles describing how this limitation was achieved? Was 2005 Lamborghini Murcielago RG-1 GT300 a 300hp car? How much slower than normal it was?

[D-Type]

This all depends on which horsepower unit you are using.  I know of several, eg DIN, SAE, all of which differ slightly in magnitude.  Also some authorities insist thge engine is tested with all ancillaries, dynamo/alternator, water pump, fuel pump etc while others allow engines to be tested in a stripped condition.
Here's a starting point: https://en.wikipedia...wiki/Horsepower

 

[guiporsche]

Sorry for not being of much help, but your two best shots would be to take a look at the SUPER GT website (particularly the archive feature where they overview past seasons, use google translator), and also the Racecar Engineering magazine. They regularly publish articles on the series.

 

But I believe you are right. There definitely came a moment when they loosened the regulations. I remember that back in the mid-2000s GT300's power output was indeed limited. That probably changed with the advent of the GT3 class, though. As for GT500, in theory it should be limited to 500HP but I would not be surprised if in practice it was always a bit nominal and their real HP figures were higher, just like in the WRC. 

 

http://supergt.net/a.../jgtc_index.htm

 

 

P.S.: Did a bit of research and two RE mags from 2011-12 indicate the following. By '11 the GT500 class was indeed limited to that figure by air restrictors. For the 2012 season the size of all cars' air restrictors was increased at once, including GT300. Hope this helps.

Edited by guiporsche, 25 July 2018 - 21:04.