I've looked at this for my RB5 and basically weight saving will be very expensive if you want to keep the car looking standard without ditching loads of items, like rear seats, carpet, etc.....
The big savers are potentially:
* Carbon Bonnet, £500 -20kg
* light weight wheels, £650 -6kg
* f/glass seats, £500 - 25kg
* remove spare, shelf, jack and tools, -20kg
So, for -71kg it will cost around £1650. maybe £1000 if you sell the old bits.
This will give a change in power-to-weight from 192bhp/tonne (245bhp at 1275kg) to 204. This means you could also increase the power to +15bhp for the same effect but the lighter car would handle better, be more reliable, accelerate faster and be more economical.
A good compromise would be to spend the money on the big-hitters (seats, spare wheel and bonnet) and then a mild tune, i.e 255bhp with 1210kg will give 211bhp/tonne (PPP STi8 is 200, I think).
I have also seem some predictive results (based on measured data) where a 30kg weight reduction on a Ford hot-hatch gave a 0.4s reduction for 50-80mph in top (or might be 4th) - 8.2s vs 8.6s. at 80mph this is about a 50ft advantage!
I also think that weight saving is only worthwhile on a car with a decent power-to-weight already. A 2001MY+ needs a large increase in power first to get any decent performance from it.

That's all.........starting to bore myself..............

[Edited by Iain P - 2/1/2003 11:13:23 AM]

[Edited by Iain P - 2/1/2003 11:21:36 AM]

[Edited by Iain P - 2/1/2003 11:27:15 AM]

I understand weight reduction can make a big difference to performance - i.e. accelerates in a straight line faster.

I like the sound of this but wouldn't know where to start.

I've heard of replacement bonnets made of aluminium but this sounds quite expensive!

So, any ideas on where I can start reducing weight...

I assume that "A Slimfast shake for breakfast?" is not the kind of constructive suggestion you were really wanting to read?! ;) :)

thanks mate. I did nearly put a note saying "please, not fat jokes" but I didn't think anyone would really stoop to it!

But in all honesty I've already been there. Being the proud owner for a CBR400 I decided to reduce the weight by being less of a fat *******. So now I'm lean(er) I want the car to be...

I've resisted putting a big fat amp and sub in the boot cos that'll make it heavier!

remove all the plastic things in the boot, the spare wheel, jack, toolset (How many times are you running flat, and, with that little wheel you can't drive long, so join a road assistance !!)
Also the covers from the lining behind the back seat...
I saved up aprox 20kg with it.
Alu bonnet and boot coming up when I can do it with the insurance...

carbon bonnet? about £500 :eek: but will look quit :cool: . carbon/kevlar seats, ditch the rears carpet, sound proofing, stereo and speakers + the above ie spear wheel etc
must be getting on for about 50kg?

mike

You can save a few kilos with alloy brake calipers and two-piece discs. Mag wheels (expensive!). Also alloy wishbones as fitted to STi's I think. OEM exhaust and headers are very heavy, too

This is assuming you have a classic shape Scoob in the first place. The new ones are much heavier.

Richard.