Hello all,

Are there any good tips for weight savings, i.e. which is better for side panels, aluminium sheet or fibreglass. Now I’m going down the BEC route, I’ve decided in for a penny in for a pound. (But I draw the line at reducing the weight of my supple, Adonis-like frame….) Are the fibreglass seats offered by many suppliers worthwhile? Any idea how much they weigh?

What would you guys recommend as a good tyre and wheel size? Jon, looking at the pictures of the Isonblade, am I right in thinking that you’re using Focus rims with 195/60 15’s? Also is that a Caterham rear view mirror? I looked at those on their website recently and the price caused my heart to stop momentarily...

Hi Max,

For some strange reason this thread caught my attention

What I do is list in reasonable detail the cars components and allocate weights to them (actual if possible, or good estimates) then order them by weight. (OK, fairly obvious I know). Then you'll find someting like 20% of the parts make up 80% of the weight (the old 80:20 rule, pareto I believe) Those are the parts that need the most attention, You have obviously addressed the main one (the engine) but I think you'll find that uprights, hubs, calipers, wheels etc. will all come higher on the list than seats and side panels.
It's easy to have 60 pounds in a front corner and saving 10 pounds isn't difficult , but when you have a seat and side panel that may only weigh 10 pounds combined then you can see the savings are more difficult.
These are just rough estimates, but you can se my point, go for the big, easy targets first.
All IMO of course.

Cheers,

Alan

Another couple of points:
Don't forget stuff left out completely weighs nothing, do you need a heater, wipers, windscreen etc.?
Also, do a cost per weight saved check. You mention the fancy mirrors, but what's the cost per pound saved? I'd guess it's actually hundreds of quid per pound
They may look cool, but aren't good value from a weight point of view.

Well, the seats you mention i find ok till your moving, then they hurt, how dare you say Ca***am ??? pheraps they copied mine, its an SPA carbon fibre one, infact all 3 are. spot on with the rubber, went that way to get the gearing rite without messing with the diff, i plan 205's on back when NOS is fitted.
With the bike route weight is a consideration so if it aint doing a job don't fit it, those who have looked close at the car will also have noted that some of the bolts have been drilled down the center, it all counts have you felt the weight of cortina callipers ? thats why i fitted willwood, plus they stop you quicker.......Alan is rite though it is worth thinking £ per Lbs, but i liked the mirrows, and you do need to see the ever shrinking cars behind you.....

It is possible to reduce the frame weight by about 10 percent and gain about 100 percent in chassis stiffness by optimising the chassis design. The total number of tubes in the chassis is also less with my modifications. I'm not certain if I made it clear that the sheet steel needs to be 18gauge to get these results so take note now. My earlier postings on this site and on the Yahoo theory forum tell you how. This is, as the figures suggest, a very significant improvement. I used the same computer analysis tools that the major car makers use just in case you are wondering. I hope you find this interesting.

Dear Max

My main aim for building is to get a very light responsive car having driven heavy production cars.!!!

Obviously bike engine is way to. lightest for torque and power are the v twins like the susuki TL. Gearbox is light but you lose out not having a combined diff like car combinations.

Ally body panels are much lighter than fibreglass.

The pucca padded seats are around 8 - 10 Kg and under £100 each see demon tweaks for example. I have also looked for the the weight of the fibreglass seats but never found it.

Have just striped the front uprights off sierra donor and cant believe the weight. I intend to machine down the discs and cross drill them. Reducing metal on the upright itself is more tricky since its cast.
Way over designed for car at hopefully 400Kg.

Few other thoughts-
No windscreen heater/wippers washer.
No reverse gear
Mid engined [avoids prop]
bike battery and fuel tank

Pete

Pete,

Thanks for the info, I’ll certainly be leaving out the windscreen and the associated paraphernalia.

I’m not sure, but I’d guess that without the windscreen in the way the drag factor of the car would be lower hence higher top speed and/or faster acceleration – any thoughts?

How are you intending to machine and drill the discs? It would be very easy to get them out of balance or seriously weaken them. Being Ford parts there are some very cheap performance discs on the market that have already been drilled and lightened for you. I know it’s not in keeping with the Locost ethos but an extra 40 quid on the budget still leaves you £210 to build the rest of the car

Cheers,

Max

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I’m not sure, but I’d guess that without the windscreen in the way the drag factor of the car would be lower hence higher top speed and/or faster acceleration – any thoughts?

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