Well, weighed my rolling chassis last night. Not impressed.

http://www.dark-engineering.com/?p=78

Rob

How much do the engine and box weigh on their own?

Going to weigh the chassis with out the engine and gearbox and work it out.

I'm guessing around 350Kg. The gearbox in my Lotus is a lot lighter. It's very surprising as the fiat coupe I took the engine out was a fast car, can't see how with the weight of the engine, at least it should be strong in a light weight car? Lol

I'll post the weight when I measure it. It is interesting. Got to get the clutch sorted on my Elise next....

Rolling chassis with a single roll hoop 520kg?!? That can't be right surely.

Fiat coupe 20valve turbo.....

???? It's a rough estimate as I weighed in with bathroom scales, but that's what I got.....

Scales accurate?

I hope not!

Uploaded a photo with the motor in, the mounts need a bit more work, but there in. Still some chassis work left to finish and it's all tacked at present.

Rob

If you are putting 1 scale under each wheel in turn you need to block up the other wheels to aprox the same height as the scales or the load is uneven
Plus your asking the scales to well past there design weight and at that end of the scale it's never accurate
A bonus to this is that you can tell the misses she probably weighs less than she thinks
But I'll leave that to you as if you phrase it wrong you'll be in the divorce courts quicker than you can say "Kit car for sale"

I wouldn't believe the bathroom scales! The tolerance on them is massive. If each one is 10% out that more like 460kg

I ditched my efforts of using 4 x bathroom scales to corner weight my car because they were so inaccurate.

It changed by min 10kg each just by unloading and then reloading the car on to them.

I don't think 520 is to bad my riot is 410 and my old blade engined striker was 430 and the cossie engined Westfield was 660 and was by far the quickest car !

I used bathroom scales to corner weight, but dialed them all in with 100 litres of water on top separately before I started = 100kg + plastic.

I got repeatable results proven by swapping them around, you need to lower gently with a trolley Jack, flat floor and always the same contact point, sit in the car and lean forwards and watch the dials leap so have a friend sit in the drivers seat holding the wheel.

Bathroom scales are accurate if used carefully. I had mine on wheeled dollies, so that they'd settle comfortably.
I now have 'proper' plates (Longacre), proving how accurate the bathroom scales were.

My R1oT (similar chassis as yours), Yamaha R1, comes in at 413 Kg, fully loaded in full road trim
My friends Riot (Zetec SE), a very similar thing to yours, came in at 570 Kg, full road trim

My stripped race ready 1000cc Mega'Busa' came in at 409 Kg
The same car with a Hayabusa, in full road trim came in at 486 Kg

I don't think (therefore) that you've to worry unduly

My xflow locost road car with full tank, spare wheel, cloth cover, small bag of tools and me in it weighed in at 630kg
I'm around 76Kg in me socks!

[Edited on 25/1/15 by benchmark51]

Thanks for the replies, some useful tips. At this stage of the build I'm only using it to estimate where things should go. I think I'll take the motor out and weigh the chassis on its own and then weigh the engine separately.

Loading it was very difficult, did it on my build table.

I'll up date next month.

Rob

My Birkin with 20v Toyo,ford box and live axle = 520 kg

I just dont believe that weight tbh! My alloy v8 without box comes in at 185kg and the box is only 65kg!

[Edited on 7/2/15 by coyoteboy]

quote:

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Originally posted by b14wrc
Well, weighed my rolling chassis last night. Not impressed.

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If it helps, my Reliant Kitten with Honda s2000 engine and box, live axle, fibrglass boby, alloy hubs used to weigh in at 790kg in road trim.

If you want to be light, go bike
What BHP @ Ft/Lbs are you expecting? In the Bhp per tonne is the main figure and just uner700Kg won't be an issue

Hi,

Standard trim the engine makes 220bhp, and a similar torque figure. I'm looking at a full rebuild with a ported and polished head, tubular exhaust manifold and more boost - so at least 300bhp maybe a little more. Power to weight is aimed at the magic 500bhp per tonne.


Rob