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Author: Subject: How heavy can I make it?
rug

posted on 14/9/05 at 05:52 PM Reply With Quote
How heavy can I make it?

This might sound a bit weird, but I worry about final inspection of my car, and I haven't even started building

I am saving up for an MK indy R1, but the problem I run into with a 150 hp engine is that the car needs to weigh in at roughly 750 kg to pass!! We have to keep power to weight at 15kW per 100 kg car.

So, what do I do? I'm thinking heavy wheels, standard sierra brakes, some lead plates under the seats... This will ofcourse not be permanent

I've read here about indy R1's weighing in at 450-500 kg. That's a whole lot of lead to add to this thing!!!

And where do they have these anti-fun rules I hear you say? - Sweden

What do you guys think?

/Carl

[Edited on 14/9/05 by rug]

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Jon Ison

posted on 14/9/05 at 05:59 PM Reply With Quote
could you "ballast" up the car too "pass" then lose the ballast ?

whoops, if i read your post properly i would have seen you are thinking along those lines anyway....... its the way too go.

[Edited on 14/9/05 by Jon Ison]






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Jon Ison

posted on 14/9/05 at 06:19 PM Reply With Quote
could you import a uk car ? LHD of course.

[Edited on 14/9/05 by Jon Ison]






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UncleFista

posted on 14/9/05 at 06:33 PM Reply With Quote
Can't you buy restricters, so any size bike can be ridden by a learner ? I'm sure I read somewhere that even 1000cc+ machines can be restricted to 30-odd hp.





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Which suddenly flips, pinning you underneath.
At night the ice-weasels come...

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Jon Ison

posted on 14/9/05 at 06:44 PM Reply With Quote
nice one, isn't it Germany where the big bikes are restricted ? could you source your engine there with proof of power output ? De restricting is usually moving 4 bits of rubber that stop the needles coming all the way open.






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benji106

posted on 14/9/05 at 07:37 PM Reply With Quote
people restrict bikes in the UK, the motorbike test means that for 2 years adfter you pass you are restricted to 33bhp (unless you do the DAS) so people just buy bigger bikes, get a certificate saying it has been restricted, and often just take it off again straight away. I imagine this would be a much easier way of getting your power/weight ratio down than increasing the weight

[Edited on 14/9/05 by benji106]





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rug

posted on 14/9/05 at 08:42 PM Reply With Quote
restricting is another way of doing it, but I hear it's a pain to have the right output certificate. I would have to prove that it has less output than original (they usualy just use the engine code, look in their database and get the output of the engine).

Might be easier than loading the thing with 300 kg of balast

/Carl

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David Jenkins

posted on 14/9/05 at 09:12 PM Reply With Quote
To be honest, if you have to meet this requirement, you would be better with a smaller, lower-powered engine, rather than 300kg of lead.

At least you would have all the fun of a light-weight car and its excellent handling...

regards,
David






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rug

posted on 14/9/05 at 09:48 PM Reply With Quote
I would just weight it down for registration, then remove it. It's quite common here. Although I don't think 300 kg is common

/Carl

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Arthur Dent

posted on 14/9/05 at 09:59 PM Reply With Quote
Add heavy carpet - maybe the housing, shag type.

What about a bench seat ala "the book"?

Or a removable hardtop made with scrap steel?





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JoelP

posted on 14/9/05 at 10:04 PM Reply With Quote
scrap lead can be found at tyre shops, if you have to buy it then i suppose you could always weigh it back in when finished






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Liam

posted on 14/9/05 at 10:05 PM Reply With Quote
Could you restrict the engine then get it rolling roaded and use the dyno printout to get your output certificate? Hmmm or dyno it with 2 plug leads missing...

Liam

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Hellfire

posted on 14/9/05 at 10:17 PM Reply With Quote
Put a false floor in it (depth of the lower chassis rails - about 25mm)and fill the space with ballast. Stick a bit of carpet over it to make it look permanent and then remove it all afterwards.

Just a thought.






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Liam

posted on 14/9/05 at 10:27 PM Reply With Quote
A quick calc...

Cabin floor area about 42x36 inches (off the top of my head and not including footwells) x 1" thick = 280kg if it's solid lead. Well that ought to about do it then! Use lead shot and you'll actually be able to get it in and out. But you'll loose density so fill the footwell floors too!

Think i'd rather restrict the engine!! 300kg is a lot of ballast to add!

Liam

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ufe777

posted on 15/9/05 at 09:30 AM Reply With Quote
300 kilos of ballast on the floor would give you a pretty amazing centre of gravity. Could play havoc with the roll centre couplings though.
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David Jenkins

posted on 15/9/05 at 09:35 AM Reply With Quote
It could play havoc with a lot of things... such as the welds/rivets that hold the floor onto the chassis!
I suspect that you wouldn't have much ground clearance either, unless you fitted strong springs.
The final worry is that the Locost chassis was designed to be light - you will be putting a lot of strain onto the suspension components.

good luck...

David






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rug

posted on 15/9/05 at 09:42 AM Reply With Quote
Think maybe weighing it down a bit, and restricting it might be the way to go.

Some way or another I must be able to get this thing registered. (after it has been bought and built ofcourse )

/Carl

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Hellfire

posted on 15/9/05 at 11:23 AM Reply With Quote
SVA in UK and import into Sweden as Jon mentioned earlier.






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Lozec

posted on 15/9/05 at 01:21 PM Reply With Quote
Carl, I wouldn't worry too much about the weight. Keep in mind that it's the cars "tjänstevikt" that's refered to and that is including driver (70kg), spare wheel (approx 10kg) full tank (30kg?) tools (10kg)

With 150hp (110kW) your cars "tjänstevikt" needs to be as you say 733kg. minus above mentioned weights you end up with a car that has a dry weight of approx 610kg. If you build with pretty much standard stuff such as sierra based rear and sierra or cortina based front you'll probably end up in the region of 500-520 kg.
I would build the car as i want to have it i and see what weight i'll come up with. Using heavy stuff only to meet the stupid requirements could not be a good way to build a car.


Good luck!

[Edited on 15/9/05 by Lozec]

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David Jenkins

posted on 15/9/05 at 01:38 PM Reply With Quote
That makes a bit more sense - the official "gross design weight" of my Locost is something like 800kg, but that calculation includes 2 passengers of 75kg each, an allowance for luggage (which I can't remember), and a full tank of petrol.

The actual weight of the car is 585kg with a full tank.

Maybe you have to do a similar calculation?

regards,
David






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andygtt

posted on 15/9/05 at 05:23 PM Reply With Quote
Need weight?..... If so I have just the thing... a spare SBC v8 engine block, after installing this over the rear axle all you problems and oversteer will be over





Andy

please redefine your limits.

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OX

posted on 15/9/05 at 07:17 PM Reply With Quote
restricter kits for every bike iv fitted them on contain 4 round metal plates with a small hole in the middle and an even smaller hole at the bottom and depending on the bike you sometimes get a throttle stop which bolts to the carbs ,,the only problem is it has to be fitted and signed by a qualified bike mechanic ,but at least you would get the proper documentation to take with you to the sva. pop to your local bike dealer and find out more
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rug

posted on 18/9/05 at 07:25 PM Reply With Quote
Great, now I'm not as worried anymore

I'll just build the sucker and see how heavy it gets. I'll probably end up needing to add some ballast, and if it's still too light, hopefully I can get away with restricting the motor.

/Carl

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JoelP

posted on 18/9/05 at 07:45 PM Reply With Quote
f1 cars have lead weights to get them up to weight. Also means you can adjust the balance!






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Messenjah

posted on 26/9/05 at 10:21 PM Reply With Quote
70kg for a driver ..... couldnt you just have someone really heavy take it down to be tested and when theyre adding on driver weight get them to stand on the scales next to the guy doing it if only it were that simple hehe i weigh 128kg hows that for ballast
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