fot
[Top] [All Lists]

Re: [Fot] Spring Rates

To: "'Kenneth Knight'" <kknight@klaenv.com>, "'FOT'" <fot@autox.team.net>
Subject: Re: [Fot] Spring Rates
From: "Randall" <TR3driver@ca.rr.com>
Date: Sun, 22 Nov 2015 11:11:05 -0800
Delivered-to: mharc@autox.team.net
Delivered-to: fot@autox.team.net
Thread-index: AdElRS3w7kTXidmETLmD+UFBFY/KrgAEyYDg
> There is a specific 
> section dedicated to understanding coil springs, leaf springs 
> and torsion/sway bars including formula's for calculating 
> rates for what you have. 

Thanks, Ken, I'll have to pick up a copy.

Sometimes it's good to get independent confirmation of the calculations.  
Here's a shot of the test bed I threw together to check
leaf spring rates.
<http://s258.photobucket.com/user/TR3driver/media/Tools/DSCF0008.jpg.html>

You could easily do something similar for coil springs.

The area of the piston in the air cylinder is known, so it's easy to calculate 
force from air pressure applied.  (There was also a
table supplied by the air cylinder manufacturer.)  The cylinder came from eBay, 
$30 IIRC; the rest came from Home Depot or MMC.
Hard to see is the second needle valve, to bleed pressure off.  Since leaf 
springs have a lot of internal friction, I measured
deflection at several points going both up and down, then used Excel to fit a 
line to the results.

The setup confirmed what I knew going in : The new leaf springs I got from TRF 
were way too stiff even for racing, let alone street
use.  But I was also able to check some original springs, and weed out the weak 
ones.

-- Randall  

_______________________________________________
fot@autox.team.net

http://www.fot-racing.com

Archive: http://www.team.net/archive


<Prev in Thread] Current Thread [Next in Thread>