Not me but my car (Formula 27).

I was looking through the IVA records and supposedly it weighed 750+kg. (I'm hoping this was with a driver on board)
It has the supposedly light Rover K series so I think its a good base to make it a bit lighter.

It has a heater, full windscreen, vinyl seats, cat and exhaust and a double skinned floor.

I'd like to keep the windscreen for now, but is it worth keeping the heater? How much would a typical heater weigh?
Any other big areas to target, its got fairly heavy 15 inch wheels which I'm looking for some comps or pro race.
Fibreglass seats? Lighter exhaust?

I'd like to be in the around 650kg with a windscreen.

Thanks

From memory, the IVA weight is the maximum design weight the car is expected to be, it fails if it's heavier than declared so it's often estimated on the heavier side. It could already be a fair bit lighter than that.

Perhaps your first visit should be to a weighing station?

As said first step is to get it weighted accurately (IIRC weighbridges get to within 10kg so a good first step).

Then it depends on how deep your pockets are and what the car has on it.

Wheels (and tyres) are big ones.
Vented discs + iron calipers? If so then solid discs with aluminium calipers are a good win (as unsprung weight is the best weight to lose)
LeadAcid Battery? bike battery, racing gel or a Lithium battery are big wins
Heaters are heavy (partly due to the water in them) but if you have a windscreen then you'll need some way of demisting it. something like http://www.t7design.co.uk/index.php?main_page=product_info&products_id=310 is a lot lighter
Dashboard, if it's thick ply/mdf then aluminium, grp or carbon are a win
Grp seats are 4-5kg each much less than vinyl, but foam+bin bag are the best seats for weight, comfort and performance if you don't mind the stripped racer look

Double skinned floor is "interesting" not seen one before. but losing the top skin would be good if it's feasible to remove it. What thickness floor? Steel or aluminium?

Plenty of scope for further savings, just look at each component and get rid if you don't need it, or think about lighter alternatives if you do.
If you really go to town you'll get down to shortening each bolt to exactly the right length (2 threads out of the nut ish) which can save 1kg on a lot of cars.

[Edited on 15/5/15 by iank]

Was that on the IVA form that comes from the test, with the brake effort figures etc on it? If so that is the calculated laden weight, and it includes driver on the day, and I think also a nominal figure for passenger and luggage.

As above:

Unsprung weight is worth some thing like 3 or 4 times that of sprung weight. So..

Wheels
Tires
Hubs
Calipers
Discs


Then I'd look at

Seats
Luxuries (heater, glovebox, rear storage, radio or whatever you have)
You - unless you are Mr Slim McTrim

Iirc youmcan get heated wind screens for de mist, this would save weight. I would exoect your car to be around 600kg but as said before get it weighed to make sure where your starting point is.

I agree with the above. ( Irony )

If you send me your nice new tyres I'll send you some with 8mm less tread on them.


On a more serious note,

the glass for my windscreen weighs 5kg, and then theres the wipers and their motor, plus demister rad & motor.

Paul G

[Edited on 15/5/15 by 907]

I've got a caterham heated windscreen. So I could get rid of the heater quite easily then, when its on it doesn't get that warm anyway.

I ditched the sierra calipers for wilwoods

Changed the type 9 bellhousing for a rs2000 ali job

nearly got it down to 500kg then added a full cage +20KG..

£££ for nothing

Just to update,
Removed spare wheel and frame - 20kg,
swapped 15's and 205 section tyres to 14's and 185 sections.
5kg a saving per wheel.
Fibreglass seats are 5 kg each and vinyls should be around 7kg so thats 4kg for the pair.

Nearly 45kg in a few small changes.

A lot can be saved on a battery easily and cheaply, my current batter weighs 11kg, and just brought one weighs 1 kg!