Stock 1200 wheel (4x12") weighs 12 lbs if I recall correctly

Cheviot Hotwires at 4kg (8.8 lbs) sound like a bargain!

Dave I weighed the alloy drums I have and they are 7.9lbs, the H190 is a wagon / roadster unit perhaps these alloy drums differ from a 240Z but I didn't think so.

Tom

My mistake:
* 240Z iron drums: 12.5 lbs
* 240Z alloy drum: 6.45 lbs
* Roadster alloy: 7.9 lbs

That's the way to go as they are larger 9" brakes instead of the 1200's smaller 8" drums

240Z drums have an adjuster hole



Roadster drums don't have the adjuster hole

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Hi Tom,
Just to reinforce what you are saying my son and I did a track day at our local racetrack yesterday. Brads first time in the car (although he knows the track very well and is pretty handy on a motorbike )
Although I only did one run on the short circuit later on in the day Brad went out after me and was within 0.3 second of my best lap - and I was really pushing the car hard and pretty happy how I drove it.
Interesting thing is that when we look at the GoPro footage my corner speed is clearly faster and I am going deeper under brakes but with Brad being around 30kg lighter he must have been picking the time up in a straight line/acceleration.
Even taking the spare wheel and wheel brace out makes a noticeable difference so maybe I too should be looking at putting the car ( or myself ) on a diet although sometimes its a fine line between having a faithful representation of a 'period' classic car and a full blown race car.
Cheers
Dave

Here's another idea: machine holes in the disc rotor.

Datsun Roadster discs come with holes

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@B110SSS as some one who came from bikes to cars; 2 wheels seems to teach you that all important controlled aggression, over do it and the ground will come up and slap you on the side of the helmet. My calculations for the 1200 has every 25lbs = 1 horsepower, granted that's going to vary slightly from car to car. One of our local racers was lost 100lbs and suddenly picked up 2 seconds a lap. At 63KG I'm not going to be shedding anything, of course my son is solidly 10kg lighter than me so maybe I need to start coaching him.

Dave thanks for pointing out the drums are different, it appears I have a set of each, fortunately I have the lighter 240z drums on the car. As for the discs, my car has 280ZX rotors and those have 4 ears that attach them to the hubs. Now it has crossed my mind to mill out the inside of the hubs as well as machine larger veins in the rotor to take weight off (keeping the rotor thickness the same). Of course these things do bring up the Chapman factor of making things so light they fail, nothing like being hard on the brakes, hearing a loud bang as the hub fails and having the car spear off the road.

There are plenty of other silly ideas like making the tranny tunnel out of aluminum than riveting it in place like you would with a monocoque.........Electrolytic corrosion what's that?

I've always wanted to do a back to back test whereby you do a few laps then replace / remove various bits to see how much of a difference it really makes. Having run the cell dry recently gave me a back to back comparison. Losing 30lbs of fuel changes the balance but it is not necessarily for the better; you gain in one spot but lose out in another so it's sort of self canceling.

And what's really silly is the fact that right next to the 1200 is a 535lb formula 500 with a 100hp Rotax engine waiting to be installed (current motor has 89hp).

Tom
If you want to see an extreme example of your idea, see if you can find the Hotrod magazine article 'Caddyhack", where they progressively strip an old Cadillac with a 500 ci motor. It was a long time ago, but maybe you can find it. I still reckon a tune up will make the world of difference, but removing all the little brackets & such, would be just as much to your advantage. Sticking the kid in the car can also help, as 'it ain"t his car & he"ll drive it as such'. Just be sure to whisper the magic words to him as he gets in - " You bend it, You buy it"

Maybe you already mentioned upgrading to lighter calipers earlier in this thread(?) But those 280zx calipers are bloody heavy. Everyone I know who rates them, (They are a pretty decent brake upgrade that still clears 13" mags) says, "oh, but it's not like you're racing". But you are.
I scored a pair of those ZX struts when I was parts hoarding. I was dismayed how weighty the calipers are. I'd expect you'd get a real world improvement there.

good idea, 280ZX struts use heavy cast iron single-piston calipers. I believe the 4-piston alloy Sumitomos bolt on, maybe the common Volvo alloys too. Or the light alloy 2-piston from a 300ZX Z32/Skyline R34

Tom's already covered
Quote:

@B310gx actually my son is the one who will treat the car nicely. I'm the one who flogs it unmercifully; he is not likely to pound the kerbs like its a tarmac rally car as I do nor dumb enough to keep his foot planted even if the car in front of him drops a wheel and is flinging rocks at our car. He'd also rather drive the formula car.

@ A14force & Dave the ZX calipers are indeed heavy but in order to fit the 13" wheels the backs of them have been milled down so they don't foul the wheel weights and are a couple of pounds lighter than standard but still 3-4 more than the Wilwoods. There is some room to safely shave another pound off the caliper and bracket. At some point I will change these.

The 280ZX rotor can be turned down to shave a pound or two. The Wilwood rotor and corresponding top hat will be 8 lbs so you can get within a pound.