Both of the cars i have in mind have sequential boxes... they add a fair bit of weight... add exhausts, turbos, pumps, bigger coolers... all adds up
My 33 GTR came in at 1600kg on WSID weight. This with about half a tank of fuel.
A friends 32 GTR came in at around 1480kg
I would have a standardish 34 would be around 1650ish