[alfa] Re:Torsion Bar Rates

["Mark Manley" <warpomatic@xxxxxxxxxxxxx>]

On Sun, 01 Aug 2004 23:34:59 +0000, Richard Welty wrote:

>From: Richard Welty <rwelty@domain.elided>
>Subject: [alfa] torsion bar mathematics?
>
>does anyone have the worked-out math formulas relating torsion bar
>diameter to conventional coil spring rates as might be found, say,
>in an ES30 front suspension?
>
>i'm working on putting a bunch of stuff together to take to the SCCA
>comp board on the recent FP limited prep listing for Alfettas, and
>one of the things i want to address is the torsion bar vs coil over
>issue (in production, you can use alternate control arms, that is
>ES30 uppers are legal, but you can't change spring type, that is
>you have to stick with torsion bars. on the other hand, in IT, you
>can't change control arms, but you can use coil over conversions
>that in the Alfetta's case don't happen to fit through stock upper
>control arms. gack.)
>
>it'd be interesting also to know what rate springs Production
>115 series Alfa drivers are using in front. anyone have any idea?

	I found this info on torsion bar rates at the link below. Might be
a help even if it is from some P car guys. :-)

http://members.rennlist.com/dan10101/docs/S_TORSON.doc
>
>A torsion bar "rate" is proportional to its length and the fourth power of its diameter. For your 26mm and 30mm 
>bars, assuming the active lengths are the same (length between the splined area), the rate of the 30 is 1.77 
>times the rate of the 26. If you are changing to a coil over, other suspension dimensions are required for the 
>comparison. A hollow bar is not as effected as you might think if the hollow is within reason. 

	HTH


                                    Mark Manley
	Hooray The Digest Is Back!

Tulsa,Ok
'84 GTV6
X1/9 x3
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