Mike, yeah, forgot petrol lighter than water, did A level physics teach me nothing?
My car isn't " all carboned up" It's got a carbon dash, sill tectors, and sexy carbon seats but that's it. Nosecone and wings just GRP. Roadsport cage, no windscreen, aeroscreen , oh it's got an FIA bag tank, don't know if that's lighter or heavier than normal. What else, dedion axle, Barnbies . That's about it. Blackbird rad, oilcooler.
I have a picture of the weight on intercomp scales with a full tank and slr rims with cr500's at 462 kg. The Barnbies are loads lighter in feel to the slr rims and the tank had 30 litres at least. So i reckon a combined loss there of 30kg say.
Neil