Real World Weight Difference: 182 FF Vs 172 Cup

[MarkCup]

Don't think it's been mentioned yet but the 172 Cup seats both came without side airbags vs the normal 172s/all 182s.

 

[willcrook]

fyi - tyres make a big difference too, with the trophy I moved to lighter wheels but ended up adding weight as I changed the rainsports to track tyres:

"
1 x pro race 1.2 with Federal RS-R - 16.8kg
1 x speedline turni corse with Rainsport - 15.9kg

interesting that despite the pro race 1.2's being rated as a lighter alloy than the speedlines, the rs-r's make it overall heavier!"

standard wheel weighs 4.3kg btw so there's a saving there (some people have stated it's 10kg on here, which is bs)
I run a redtop 20 battery at 5kg ish (6kg saving from standard halfords replacement)
the aircon including pipes+everything was 11kg
stereo was 2kg IIRC

 

[Mr Plums]

standard wheel weighs 4.3kg btw so there's a saving there (some people have stated it's 10kg on here, which is bs)

​A standard 16" 182 wheel weighs 4.3kg?

 

[Whitetac]

Doubtful

 

[Mr Plums]

Doubtful

He might mean steering wheel

 

[willcrook]

He might mean steering wheel

yus :> (though it is probably about 16" )

 

[alistairolsen]

Colin chapmans test were on F1 cars not clios, so I dont think the number can be used quite that directly, but its still certainly true that laptimes WILL be effected more by 10kg of unsprung loss than of sprung loss

Its also worth thinking about the height of weight, 10kg lost from the windows is worth more to your laptimes than 10kg lost from the underseal under the car for example.

What he said was spend £1 per Pound of sprung weight saved and £3 per pound of unsprung weight. It wasn't a mathematical idea based on laptimes, but a measure of the relative importance and difficulty of saving from both areas.

Chip know's this anyway, but there's no correlation that 10kg of unsprung is as good as Nkg of sprung weight, its simply not true, what is true is that sprung weight affects the linear inertia under acceleration and braking and also the maximum cornering speeds due to the curve of tyre grip versus normal force which isnt quite linear. In addition to this, unsprung weight also affects how well your wheels stay in contact with the ground and therefore the grip you have available and rotating mass applied rotational inertia as well which will resist acceleration and braking (so brake disks are basically the devil, along with wheels and tyres.)

It's also worth bearing in mind that in very light cars, the unsprung weight begins to dominate, especially in those days in that you could build a light chassis and bodywork and so on, but wheels, brakes, tyres etc were all fairly basic. In this situation you end up to some extent with the tail wagging the dog and it becomes even more important to save weight in the right place.