RE: ALMS Series
Been a fan since Imsa. Lets see.
The 675 cars are lighter, typically more fuel efficient and faster around corners. A 675 car actually won outright once, at Sears Point earlier this year (I was there)
The 675 cars suffer because they are not run by factory teams, but privateers with smaller budgets (though they are very, very well prepared)
The GTS Cars have beaten the 675 cars because the 675 cars are pushing the limit. The only truly competitive ones are the Lola MGs which have a 2 liter turbo charged motor. The motor is very, very fragil as compared to the 6 liter ferrari (naturally aspirated) or the 7 liter vette (also NA)
It also seems that the GTS cars have had more development of late than the others. The Ferraris are really just reaching their prime, where as the LMP 900 cars are all older - the Panoz dates to 99, the Audi to 2000 and those are really the only competitive 900s. The Riley and Scott could be competitive, but the two teams running them are again privateers and also new to the car this year.
The 10 hour race at road atlanta is coming up. Ought to be a good one.
Scott