Coupe weight loss program!

Has anyone made a serious attempt to reduce the weight of the coop? Mines off the road now for 6 months so plenty of time to play about with it.

I've searched the forum but not found much on weight reduction so any pointers would be great.

It is a heavy old lump for it's size!

Cheers Guys and Girls

Front seats are heavy -17kg each so a couple of carbon Buckets will save a bit (20kg+) and since you can't get into the back, the rear seats are about 7kg, rear door cards about 2kg each. Spare wheel and jack is fair bit as well

The bonnet is a weighty item - fibreglass of carbon version

Light weight battery, 8kg in stead of 13kg

Depends how serious you want to get? is this a bit of triming for a road car or full on race car we are talking.

my car is now -30,5kg .
sparewheel, tools, back window viper, original intercooler mounting place, other stuff from the front, new intake manifold, interior from the boot. ( over 5kg ) etc etc.. I have listed all my parts...
still to come: 5kg battery ( -13kg. standard vas 18kg )battery place: original 1.8kg, new about 200-300g

new bonnet: weight loss about 15kg.
new seats : weight loss unknown..
my goal is under 1200kg, I dont have stereos and no A/c also
so about 20kg lighter, than normal.( that makes it now -50kg )

Do the smaller batteries provide the same oomph/power as the normal ones (sorry for the non-tech term!), for a normal car with A/C etc? If so it seems like a logical move to take some weight out from between the front wheels.

Sorry for the hijack!

At this year's Ten of the Best, I stripped out the following:

Front seats (replaced with kevlar race seats)
rear seats
door cards
all speakers and headunit and CD player
all seatbelts
A, B and C pillar covers
rear parcel shelf cover
carpets and soundproofing beneath
centre console and gearlever surround
all boot lining
spare wheel, jack & tools
rear wiper and motor

I reckon it added up to about 100 - 120kg

However, it also added up to one of the worst headaches I've had in years - the noise was unbearable for anything above 20 miles (which was a bit of a problem, as Elvington was 120 miles away). I really should have used earplugs.

If you had a lot of commitment and deep pockets, I reckon you could get another 100kg off the car, by using carbon fibre for the bonnet, doors and bootlid. If you were *seriously* well off, you could probably replace the roof panel and rear three quarters with carbon as well - another 50kg maybe?

However, you'd still end up with a car over 1000kg AND it would be hateful to drive.

If you want a lightweight racer, start with a lightweight car. Why do you think the fastest FWD cars at TOTB were tiny (Corsa, Nova, Tigra, CRX)

A member here in Sweden has made glassfibre doors which were a great deal lighter (THEY are heavy), also hood and other things on his 16VT ('94!). That'll be light!

I reckon I could loose 10kg by going on a diet. It all adds up.

yeah after the bonnet the doors are the next heaviest thing that can easily be replaced.

If you get a gel battery they have the same cranking power but less capacity. So constant on/off is a problem but normal starting/stopping is not really. If you are worried you can split-charge to a normal battery and gel battery and just remove the normal battery when you race.


Aircon is heavy if you add up all the bits I bet it is 20kg+

A lot of the aluminium engine mounts are well and truly overengineered and so you could take quite a lot of weight off them, probably 15-20kg I would guess.


The other thing with weight loss is you want to do it in the right places. Rear subframe is extremely heavy and unnecessarily so but the problem is that if you lose the weight off that it will upset the rear balance quite a bit.

You don't want to be riding on a full tank either. (or an empty one)
so you can put in plastic balls to reduce the volume.

FYI - have been using the 7 Kilo deka 16 battery for a while now and haven't had a problem starting due to lack of charge (but haven't got through winter yet)

n.b. these are annoyingly expensive

No one said wheels or tyres. You can save a lot on wheels and they are unsprung mass of course.

Does anyone have some real world measured figures before and after?

punch in project lightweight and you'll see where I'm at the moment. I will be replacing my clutch in the near future so I'll be able to fit a lightweight flywheel at the same time!!.... On the 20v turbo the biggest problem isn't the overall weight (although it is too heavy) but the weight balance, the front is obviously heanier than the rear and the front right on rhd cars is approximately 15% heavier than the left... I was going to move the battery to the boot but until I can sort the left right imbalance that'll have to wait.
My next project is to remove the sunroof and replace with std panel... Another 20kg's gone.... Yeah!!!

Cheers Tim

Update - the battery drained once due to lights left on and (despite the ad saying it handles deep discharge) hasn't been the same since - certainly won't hold charge for > 14 days.

To help out got a solar charger from maplins 'cos I don't want to be stuck in the arse-end of woolwich waiting for a jumpstart again!