Practical 400kg sports car

[Watchman]

It's the style I'm after rather than the fly-weight... but this isn't my thread. I just love the intended style.

I know how heavy the VAG unit is.

I really want this:



But Suzuki won't make it. More details here:

http://www.suzukisport-racing.com/english/product/...

[Ferg]

Too heavy, I know, but Bertram Bakker has his Audi 1.8T with DSG Libra up for sale. That's a serious car!!!

[fridaypassion]

Interesting project bookmarked.

I have a VX220 which is 855kg or thereabouts this would be a good starting point for you to look at. (or an S1 Elise) In comparison to the Fury its totally practical. Its got a roof, heater, windows etc its a fully functional car. Its also pretty light by comparison to most road cars.

Weight loss well you can shave about 40kg off removing the small amount of sound insulation and chopping one or two un needed bits here and there so call it 800kg on a good day. I would say to make a car thats anywhere near useable and safe on the road you need to be looking closely at the chassis and probably going down the carbon fibre route. I dont think without pretty extensive use of lightweight composites you are going to get anywhere near 600kg let alone 400.

That said a practical car with a roof, lights etc that was anything like 600kgs would be a brilliant achievement. 400 would be a miracle!

Best of luck I will be watching with interest. If you need any help with the composite stuff let me know.

[Ferg]

fridaypassion said:

I dont think without pretty extensive use of lightweight composites you are going to get anywhere near 600kg let alone 400.

I reckon the Libra would be easier. Lighter wheels and just 4 of them. Lighter seats. Bespoke windows (half of them are in the doors) . Carpet. Sound insulation. Ally rad.

[CraigyMc]

fridaypassion said:

I have a VX220 which is 855kg or thereabouts this would be a good starting point for you to look at. (or an S1 Elise) In comparison to the Fury its totally practical. Its got a roof, heater, windows etc its a fully functional car. Its also pretty light by comparison to most road cars.

The 340R was 705Kg, the 2-11 is about 670kg in road form.
An old acquaintance has a race-biased S1 Elise which has been brought down to ~670Kg (lighter bits in lots of places, including a very light exhaust).

A 400Kg usable car like this? I'd like to see how it could be done.

C

[Scuffers]

CraigyMc said:

the 2-11 is about 670kg in road form.

no chance, add at least 125 to that!

[Tango13]

I think the OP needs to forget cars cars at 400kg and start looking at bikes for that sort of power to weight ratio.

[robcollingridge]

I know bike-engined cars are not everyone's choice but, personally I love them and it is the only way you can get close to the weight I'm talking about. A 2003 R1 engine is 60.5Kg with all the bits to make it run (no exhaust manifold) and that includes the gearbox, clutch, etc. It is not ideal in town but, I love it in my Fury R1, which is mainly used on the road. The sound and 11,500rpm red line are a big part of it.

I loved my S1 Elise too but, it was a production car. No production car will get close to 400Kg because of safety regulations and manufacturers liability. This is a one-off and I don't have to worry about such things, just getting it through the IVA test.

I guessed safety would crop up at some point in this thread. Is a 400Kg car any less safe than my 450Kg Fisher Fury R1? I don't know the answer to that but, I'm perfectly happy with my Fury and I drive it like it is a motorbike with 4 wheels and understand the consequences of hitting another car. It is a lot safer than a motorbike, in that I can't fall off it.

It amuses me that people think 400Kg is so far from realistic, when I have a 450Kg car sitting in my garage that is quite close to what I'm trying to do. As I said before, my 400Kg target does not include the removable hard-top roof. It this such a big leap?

My worst case scenario is that I end up with a car that is faster and lighter (and more expensive) than my Fisher Fury R1.

[Ferg]

I have to say Rob, I believe it to be absolutely achievable!

[robcollingridge]

One simple example of what I'm talking about is this indicator stalk/switch I've fabricated using carbon fibre this weekend. I can do this because I'm using clever electronics, which also mean much of my wiring loom can be 7/0.2 wire (which weighs just 3.5g per meter). This indictor switch will be mounted on the carbon fibre paddle shift and it weighs just 8g.



I'm not saying 400Kg is an easy target to reach but, these are the kind of things I'm doing to make it happen.

Rob

[dtmpower]

I'll try and dig out a link to a car with an r/c style vacuum formed body in lexan.

[xRIEx]

robcollingridge said:

It amuses me that people think 400Kg is so far from realistic, when I have a 450Kg car sitting in my garage that is quite close to what I'm trying to do.

Law of diminshing returns, for one. The more that is taken off, the less opportunity to save weight.

You said yourself, you have to add a reverse function to get through IVA, whether a reverse box, or more likely if mid-engined, a starter motor acting on the diff, it's going to add weight over the 450kg starting point. You want a windscreen which being glass is going to weigh more than the flyscreen on your Fury. In addition, IVA requires a windscreen wash and demist. Sure, you can take it all off after, but that then reduces the practicality.

I assume your Fury used Sierra components (if IRS), and not being an engineer I have no idea if they can be replaced with lighter alternatives for a lighter car. Obviously the suspension has an easier time, drive components only have to deal with 70lbft of torque compared with a Pinto's 115lbft.

Doin't get me wrong: yes I'm sceptical, but I would love to be proved wrong and will be following your project with great interest (saw your website a couple of weeks ago). I can just imagine you ending up with a 370kg, carbon tub mid-engined monocoque. And because I'm a sceptic, I would need to drive it before I believed you

robcollingridge said:

...the carbon fibre paddle shift...

Surely if you're going mid-engined the linkages would need to be quite long; wouldn't a floor-mounted shift will save vital grams?

Edited by xRIEx on Sunday 8th July 21:27

[MrGRT]

Rob, the mevabusa has a claimed weight of 390kg. So I think is doable.




Sorry for the pic, comes from the sellers webpage.

[kambites]

Yes but that's hardly a practical every-day car.

[fridaypassion]

10kg to fit a roof, doors, heaters/washers? easy!

[anonymous-user]

Rocket, cough, Rocket:

[anonymous-user]

sounds like you should have a look at the Ginetta G4 as thats basically a fury with a roof...

[Tyrewrecker]

kambites said:

Yes but that's hardly a practical every-day car.

Not much less practical than friends who use 340r's as dailys?

[anonymous-user]

robcollingridge said:

One simple example of what I'm talking about is this indicator stalk/switch I've fabricated using carbon fibre this weekend. I can do this because I'm using clever electronics, which also mean much of my wiring loom can be 7/0.2 wire (which weighs just 3.5g per meter). This indictor switch will be mounted on the carbon fibre paddle shift and it weighs just 8g.



I'm not saying 400Kg is an easy target to reach but, these are the kind of things I'm doing to make it happen.

Rob

You need to get the car on to a CAN based system, that way you can do everything with 3 wires (B+, CANH, CANL) !

[Turn7]

Rob, your Fury is one of the best Ive ever seen. If you love it that much, surely you would be better spending out on making the Fury a more user friendly car ?