spiderman01980
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 posted on 26/11/09 at 09:48 PM |
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coil springs
does anyone know what lenght spring i need for a 13"open/9"closed shock i know the I.D and rate just dont the length?!
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will121
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| posted on 26/11/09 at 10:46 PM |
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are they adjustable spring platforms/ride height? can you not extend fully and measure from top to lower platform (when wound down) to obtain free
spring length?
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cosmick
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| posted on 27/11/09 at 02:22 PM |
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Apparently the formula is 5" shorter than the open length so if its 13" open, then in theory it should have an 8" spring.
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procomp
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| posted on 27/11/09 at 02:55 PM |
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Hi
Nope it's all dependent on the shock desighn. Ie a 13" protech would want a 9" spring. But a 13" spax would want a different
length.
There is no one fits all answer for this one as poundages will also play apart.
Cheers Matt
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Angel Acevedo
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| posted on 27/11/09 at 08:00 PM |
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Somewhere in this forum or the locostusa forum there`s one excel spreadsheet that can help you with it.
You will need to imput the following:
- WEIGHT MEASURED AT WHEEL
- UNSPRUNG WEIGHT (SEE NOTE 1)
- %AGE OF WHEEL TRAVEL AS 'SAG' (SEE NOTE 2)
- TOTAL WHEEL MOVEMENT (SEE NOTE 3)
- TOTAL RESULTING SHOCK STROKE (SEE NOTE 4)
- SPRING PRELOAD (SEE NOTE 5)
There`s an ongoing debate wether is it or not an accurate way to setting up spring rate and length, but I used to order my shocks and springs ad the
values I got were really close to the ones being used by a guy that is driving a completed car with very similar weight and arrangement.
I have the file, if you can´t find it I may post it later.
HTH
AA
Beware of what you wish.. for it may come true....
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mr henderson
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| posted on 28/11/09 at 09:21 PM |
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Your first concern is to get the ride height correct, therefore you need the spring to be a speciofic length when it is fitted.
What length it ends up at is a function of its open length, its poundage, and the amount of weight on it.
For instance
10" spring, 200 lb rate, 400lb's weight on it will compress to 8"
9" spring, 400lb rate, same 400 lbs on it, will compress to 8"
These numbers are just examples, BTW
Mike Capon's spreadsheet (it's here on this forum somewhere, sorry I don't have a link to it) will help you calculate the correct
spring length
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MikeCapon
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| posted on 30/11/09 at 09:17 AM |
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Spreadsheet attached. Please do not hesitate to ask if it's not clear. U2U or post on this thread.
Cheers,
Mike
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