Production Car Racing (GT4, CTSCC, PWC GTS/TC, MX-5 Cup, etc)Touring Cars 

  • Thread starter CodeRedR51
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That’s actually pretty wild to think about, hey. I know there’s a good 35 years of technological evolution here, but still.

I’ve absolutely been loving the GT4 racing in iRacing lately and it’s given me a whole new appreciation for them and their capability to produce some great racing, so I really hope the series continues its upward trajectory here in Australia. And speaking of the 12 Hour, hopefully we see more GT4’s competing from next year onwards, give those big GT3 boys an extra challenge.
I don't know where to start as far as specs for the various GT4 vehicles, but I can offer a few for the Sierra RS500 that dominated the domestic Group A category in 1989.

All the front running cars had in excess of 500bhp for the beginning of the year.
It's fair to assume they had around 10% more for a banzai qualifying run.

Category regulations meant that all Sierras weighed a minimum of 1100kg, and had to use tyres no wider than 9" driving through a 5-speed gearbox.

Finally, of the cars involved in the Top Ten shoot out, Dick Johnson was fastest up Mountain Straight at 252km/h, and fastest down Conrod at 285km/h for a lap time of 2:16.79

By comparison, Brock was 4km/h slower up Mountain Straight, and 3km/h slower down Conrod, but still laid down a 2:15.80
This despite coming under scrutiny for trickery involving the under bonnet fire extinguisher placement in relation to the turbocharger intake.

The only non-Sierra in the 1989 shoot out was Jim Richards in the HR31 Skyline GTS-R.
235km/h up Mountain and 266km/h on Conrod for 2:20.09
Gibson Motorsport never quoted any more than 420bhp from the RB20DET.
 
Yeah, you’re looking at about(before BOP): 350-380bhp/1100kg for an Alpine A110 to about 550bhp/1400kg for an AMG GT. The new M4 GT4 Evo has 518 hp.
 
Do we know what vehicle is used as the target for BoP?
Depends which car is winning.
Here are two. One from the 2024 12H and one from GT4 European Series at Misano.


BOP adjustment for the Mustang at PI.
 
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