[DeTomaso] Spring rates, math quiz

[Julian Kift]

Mikael,

Do you know the corner weights of the Longchamp or have access to corner weight scales? If you could know that mass then you can estimate the reactive spring rate lbs/inch of your current springs from the 13cm of compression you have mounted and uncounted. I say reactive as it would only be an estimate given the angle of the shocks and suspension travel and the fact some of the corner mass is the wheel, rotors etc. (unsprung weight) With that information it should fairly simple math to estimate the length and spring rate that provides the ride height you desire.

The alternative is to take a spring and compress it by 1 inch on a scale and read what weight that takes, which is your spring rate in lbs/inch, but you still need the unstrung mass of the Longchamp to estimate the static weight (compression) on the spring.

Of course you could just get a set of aftermarket adjustable shocks and springs!

Julian

> Date: Fri, 13 Jun 2014 21:30:33 +0200
> From: mikael_hass at mail.tele.dk
> To: mbefthomas at comcast.net; detomaso at poca.com
> Subject: [DeTomaso] Spring rates, math quiz
> 
> 
> So all you math genuises, here's a question. My orig Longchamp springs of unknown spring rate are too hard/long now that I have replaced heavy iron: headers, heads, intake. Tomorrow I'm going to a place where they have springs on shelves so I can measure and find close origs in size. I.D. has to be exact (9cm). And I plan to find springs from a car with a V6, preferably sporty soo not too soft. And I realize that I will have to buy several (they're about $60 each) to experiment to get the height I want. 
> 
> But here's the question. Orig springs are 38cm free, and 25cm mounted in shock and weight on car. I'm looking for around 20cm, lowering 5cm. Question: if they have springs with proper diameter, but are maybe 33cm at rest instead of 38cm, what is the equivalent height decrease when weight is on spring and mounted in shock? Is there a formula?
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-------------- next part --------------
   Mikael,
   Do you know the corner weights of the Longchamp or have access to
   corner weight scales? If you could know that mass then you can estimate
   the reactive spring rate lbs/inch of your current springs from the 13cm
   of compression you have mounted and uncounted. I say reactive as it
   would only be an estimate given the angle of the shocks and suspension
   travel and the fact some of the corner mass is the wheel, rotors etc.
   (unsprung weight) With that information it should fairly simple math to
   estimate the length and spring rate that provides the ride height you
   desire.
   The alternative is to take a spring and compress it by 1 inch on a
   scale and read what weight that takes, which is your spring rate in
   lbs/inch, but you still need the unstrung mass of the Longchamp to
   estimate the static weight (compression) on the spring.
   Of course you could just get a set of aftermarket adjustable shocks and
   springs!
   Julian
   > Date: Fri, 13 Jun 2014 21:30:33 +0200
   > From: mikael_hass at mail.tele.dk
   > To: mbefthomas at comcast.net; detomaso at poca.com
   > Subject: [DeTomaso] Spring rates, math quiz
   >
   >
   > So all you math genuises, here's a question. My orig Longchamp
   springs of unknown spring rate are too hard/long now that I have
   replaced heavy iron: headers, heads, intake. Tomorrow I'm going to a
   place where they have springs on shelves so I can measure and find
   close origs in size. I.D. has to be exact (9cm). And I plan to find
   springs from a car with a V6, preferably sporty soo not too soft. And I
   realize that I will have to buy several (they're about $60 each) to
   experiment to get the height I want.
   >
   > But here's the question. Orig springs are 38cm free, and 25cm mounted
   in shock and weight on car. I'm looking for around 20cm, lowering 5cm.
   Question: if they have springs with proper diameter, but are maybe 33cm
   at rest instead of 38cm, what is the equivalent height decrease when
   weight is on spring and mounted in shock? Is there a formula?
   > Sent from my BlackBerry Q10
   >   Original Message
   > From:
   >
   > _______________________________________________
   >
   > Detomaso Forum Managed by POCA
   >
   > DeTomaso mailing list
   > DeTomaso at poca.com
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