speedyxjs
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| posted on 10/11/08 at 07:50 AM |
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Suspension
Can i just check iv got this right?
The spring rates are the maximum weight the springs are deisigned to carry? So for a FR layout with say a Jag engine, and you estimate the car will
weigh less than 1000kg, one would use 2 x 300 on the front and 2 x 200 on the back?
Also the length of the shocks are the distance between the suspension bracket and the wishbone when level?
How long can i resist the temptation to drop a V8 in?
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mr henderson
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| posted on 10/11/08 at 07:54 AM |
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quote:
Originally posted by speedyxjs
Can i just check iv got this right?
You can indeed check, and no, you haven't got it right.
Spring rates are a measure of how much force is required to compress the spring, normally a distance of 1 inch, so, 300lb sping needs a force of 300lb
to compress it by one inch
More later (when I've had breakfast
John
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speedyxjs
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| posted on 10/11/08 at 07:57 AM |
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Thanks i didnt think id got it right.
How long can i resist the temptation to drop a V8 in?
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Mr Whippy
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| posted on 10/11/08 at 08:05 AM |
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Your car will weight less than 1000kg? but that leaves only 1kg for everything bar the engine!
Who are you buying the coilovers from? Normally you want to specify the compressed and uncompressed lengths. You need to then decide how compressed
you want the springs to be normally, use that & the spring rate to determine the spring strength you require.
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Mr Whippy
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| posted on 10/11/08 at 08:10 AM |
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linky
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MikeCapon
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| posted on 10/11/08 at 08:22 AM |
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Hello Mr Speedy.
Have a look at this spreadsheet. If you need a hand then just say the word.
Cheers,
Mike
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mr henderson
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| posted on 10/11/08 at 08:24 AM |
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OK, 2 pieces of toast and marmalade later-
Let's start by assumng (for simplicity) that the springs on your car are vertical, and acting in line with the centre of the contact patch of
tyre to ground.
Let's assume, as an example only, that the corner of the car in question weighs 400lbs.
Now, to hold that corner up the spring is going to need to be compressed by 400lbs. If the spring was a 200lb spring then it would need to be
compressed 2". If a 400lb spring was used then it would only be compressed 1". The 400lb spring would be twice as stiff as the 200lb unit,
but both could be used if enough movement was available.
In cars with wishbone suspension the spring is normally at an angle, and moves less than the wheel due to the spring being closer to the pivots (basic
lever physics), so you will need to measure and calculate to arrive at a correct spring choice.
edited to add link (which contains a couple of other links)
http://www.locostbuilders.co.uk/viewthread.php?tid=98402
John
[Edited on 10/11/08 by mr henderson]
[Edited on 10/11/08 by mr henderson]
[Edited on 10/11/08 by mr henderson]
[Edited on 10/11/08 by mr henderson]
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speedyxjs
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| posted on 10/11/08 at 02:07 PM |
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quote:
Originally posted by Mr Whippy
Your car will weight less than 1000kg? but that leaves only 1kg for everything bar the engine!
That is the estimated weight with driver and passenger 
Thanks Mike and Mr H. Il look at the links later 
ETA - I forgot i posted that 
[Edited on 10-11-08 by speedyxjs]
How long can i resist the temptation to drop a V8 in?
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