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The quest for a lighter car.........


Clay Head

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I've never really looked at making my car lighter before but figure its now the best way to feed upgraditis. I am looking for the best value route to saving around 50-70Kgs. (Don't even go there with the go to the gym, stop eating pies, gags Paul McKenzie!). With 160bhp, this should push the car up to around 310bhp/tonne as it weighs about 570Kgs at the moment. I have a De-dion XF with dry sump, standard bell-housing, pre 96 chassis, cycle wings, 13" minilites and pretty standard elsewhere.

 

Does anyone have a suggested route to the magic 500Kgs with an estimated cost. Changing the bell-housing is a given I suppose , saving 8Kgs?

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Hi

 

Depends on how you are

My goal is too loose about 15 kilos on the driver

and the car because I am in when I drive

 

2 weeks of no sugar and fat so 4 kilos less

12 kilos remaining

but the bicycle already works better ...

 

For the cat :there are no heater, no carpet, no hood in the boot, no spare wheel

no keys or something to help in case of breakdown

no dry sump, no big wheels,

 

But I want to keep : decent seat, windscreen, fiberglass items

security and budget reasons

 

regards

 

 

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I can see that this afternoon's blast has got you thinking.

 

Suggestions:

Hood and hood bag.....but you like to stay dry

Heater...but you like to stay warm

Spare wheel........but you've only just bought it

Windscreen......but you like to keep your hair in place

 

If I was you I'd concentrate on the pies..although 40 kg weight loss might be a bit ambitious.

 

Paul

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My view is that this approach is cheaper than looking for more power. My XF is at a nice practical / reliable point and I would not want to take it any wilder. I suppose its a blend of practicality and cost vs result!

 

How much weight does the carbon fibre nose and wings actually save, for example and at what cost?

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I can send you my 'weight of things 7' spreadsheet that should give you some scope.

Wheels and tyres and spare are a good start. Then there's the heater (not much really), the screen,

side screens, hood/bag, leather seats. Then there's silly like one of the horns, the reversing lamp,

etc etc etc... hours of fun.

 

I have lost some 75 kgs off my HPC from touring to race spec. Now with no passenger provision or anything that isn't needed for the track...

 

/Steve

 

My racing pics, 7 DIY, race prep. Updated often here

Hants (North) and Berkshire area club site

here

 

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My advice is to never, ever, say

 

"That's only 1/2 a kilo so it doesn't matter."

 

Like anything else that's worth doing, the rewards are for those who apply themselves and who pay attention to the details.

 

A few "silly ones" for you:

 

carbon replacement for wooden boot floor/ali boot floor cover, vinyl tax disc holder, vinyl front numberplate, racing battery, carbon mats, titanium exhaust and no cat, HE30 cam cover, revised front light setup = total saving @ 20kg's approx.

 

And that's off an SLR which already was quite pared down to start with. You've just got to keep shedding those little 250g chunks and before you know where you are you've lost lots.

 

A bit like dieting really!

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40kg is possible 70 would be difficult. On my X/F I have done the following

 

I would start by removing the seats and replacing with race ones, I would then fit an ali gearbox casing and bell housing. Buy the lightest wheels you can afford, weigh your exhaust silencer and replace it with a lighter one of about 4.5 kg (I saved 6 KG by changing). Ditch the heater if you have one, remove the spare wheel. A lighter battery can save some weight as well

 

If you can live without a screen and its ancillaries then that could go as well.

An Ali rad is nice but in terms of pounds spend for kgs saved is expensive as are lightweight starters, alternators and brake calipers .

 

Edited by - Graham Perry on 11 Nov 2002 08:49:43

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Weight saved so far on my road car:

 

Odyssey battery 2.5 kilos

Titanium silencer 2.5 kilos

Removed seats and fitted bench seat 9 kilos (futher savings to come when I make my own seats)

Ali bell housing 6 kilos

Ali crank pulley 1.1 kilos

Carpets under seat 1.5 kilo

Replaced horns for single motorcycle one 800 grams

Tax disk holder 125 grams (tax disk stuck in windscreen)

 

That's over 23 kilos. I'm still nibbling away at things.

 

I have some ali 4 pot Wilwoods which will save 4 kilos, some smaller fog and reversing light around 500 grams. Luke Beaumont is making some fibreglass rear light mounts which will probably save another 500 grams. I've got some iddy biddy motorcylcle coils which will save 700 grams and a box of titanium and aluminium nuts and bolts to fit. Also making some titanium sheet rear wheel arch protectors, another 700 grams. The originals weigh 1 kilo! Carbon fibre would not be in keeping with the look of my car.

 

Might get rid of the heater as I don't seem to be using it much, but I'm keeping the screen hood, etc. Probably keep the spare wheel for rear impact protection rather than anything else.

 

The best thing about being small is that I only weigh 60 kilos, so I have a head start on some of you more corpulent types. 😬

 

AMMO

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wheels and tyres are a good poin to start.

get rid of the spare, fit mag wheels and ACB10s (or CR500s) and you'll save about 30 kg (assuiming you're on 14", and not ACB10s or CR500s).

 

losing the screen, wipers and washer bottle is another 10 or so.

 

tillets (GRP, or kevlar if the wallet stretches)

 

carpets are easy to get rid of.

 

After that you're into a few kg at a time - carbon wings/nose, battery, ali rad, spare wheel carrier etc.

 

plus any XF specific bits.

 

HOOPY 500 kg R706KGU

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I went through this exercise with my Westy and it's a combination of lots of little things plus a few big things which makes the difference. I reckon I've stripped about 70kg out of my car, but then I had a lot more to remove and the new engine and gearbox are quite a bit lighter than the Xflow.

 

For example, ditch the screen and heater, but also rip out the wiring from the loom. OK, might seem a bit extreme but in swapping over from a car with a heater, screen, wipers and a multitude of instruments to one with an aeroscreen and Stack display I reckon I stripped about 80 feet of wire from the car. And if I was starting from scratch with the loom I'd save even more by using thin-wall high quality wire throughout.

 

Then there's things like using aluminium bolts in low stress applications, or even gluing things rather than riveting or bolting them in place. Kick strips and wheel arch protectors for example. I've also made a seat out of 2 pack foam which saved quite a lot of weight.

 

Also have a think about things near each end of the car - can you, for example, fit a lighter radiator ?? What brakes are you using front and rear ? Can you justify a set of magnesium wheels ? That sort of thing.

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I am on the very same quest.

 

Spare wheel is coming off this weekend which will save 17kg at the rear end.

I am going to replace the 15" prisoner alloys that weigh 15.5kg (with tire) each with

my minilites that are 12.7kg (with tire) so that is an 11.2kg saving.

 

SO ... in one weekend I will remove 28.2kg which is more then the weight of a full tank of petrol (assuming petrol has an SG of 0.72)

 

hmmmm, i need to lose a few kilograms too but that aint so quick and simple!

 

Alex B

 

S713UMY

1.8K Viper Blue

 

Edited by - abirtwisle on 14 Nov 2002 15:25:24

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Last weighing = 517 kgs with slicks and race wheels, no plates, no headlamps etc etc. This was with race fuel load.

I will be lighening the flywheel by some 5kgs this winter 😬

Not sure if TB's weigh less than Webers... there is less to them... Ooooh must go out and weigh them... back soon

 

/Steve

 

My racing pics, 7 DIY, race prep. Updated often here

Hants (North) and Berkshire area club site

here

 

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If it's not necessary - throw it out

If its big and solid - drill holes in it

If it's steel cast iron or granite - replace it with titanium,rare and costlyium or plastic.

 

There must be some truth in this somewhere 😬

 

Paul the 3F's

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