Suggestions for Spring Rates - Track Car
10-29-2008, 04:52 PM
#31
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That's not what you are calculating. You are calculating the effective rate of the spring, itself.
I didn't make up the equation, I just plugged in the numbers. The numbers show an inverse relation between the coil spring and the t-bar( which ofcourse is also a spring, but not in a linear sense.)
That more complicated equation is above my pay grade.
I didn't make up the equation, I just plugged in the numbers. The numbers show an inverse relation between the coil spring and the t-bar( which ofcourse is also a spring, but not in a linear sense.)
That more complicated equation is above my pay grade.
Ok, I think maybe you just had the equation backwards. This makes more sense to me:
(effective rear spring rate - effective tbar rate) /.56 = spring rate
So, if you are shooting for an effective spring rate of 600#, and you have t-bars with an effective rate of 330#, then you can find the ideal spring rate for a coilover as follows:
(600# - 330#) / .56 = 482# (so you would try to find a 482# coilover spring)
The only caveat would be that if the .56 should be .42 or some other number based on the motion ratio described by trucho.
EDIT: Apparently, the .56 in the equations above should be .42 (motion ratio of .65 squared).
(effective rear spring rate - effective tbar rate) /.56 = spring rate
So, if you are shooting for an effective spring rate of 600#, and you have t-bars with an effective rate of 330#, then you can find the ideal spring rate for a coilover as follows:
(600# - 330#) / .56 = 482# (so you would try to find a 482# coilover spring)
The only caveat would be that if the .56 should be .42 or some other number based on the motion ratio described by trucho.
Last edited by vt951; 06-29-2009 at 01:26 PM.
10-29-2008, 04:58 PM
#32
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Ok, I think maybe you just had the equation backwards. This makes more sense to me:
(effective rear spring rate - effective tbar rate) /.56 = spring rate
So, if you are shooting for an effective spring rate of 600#, and you have t-bars with an effective rate of 330#, then you can find the ideal spring rate for a coilover as follows:
(600# - 330#) / .56 = 482#
The only caveat would be that if the .56 should be .42 or some other number based on the motion ratio described by trucho.
(effective rear spring rate - effective tbar rate) /.56 = spring rate
So, if you are shooting for an effective spring rate of 600#, and you have t-bars with an effective rate of 330#, then you can find the ideal spring rate for a coilover as follows:
(600# - 330#) / .56 = 482#
The only caveat would be that if the .56 should be .42 or some other number based on the motion ratio described by trucho.
550-177/.56=666.07 <<<25.5mm bar
550-126/.56=757.14 <<<23.5mm bar
10-30-2008, 12:11 AM
#36
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The rear is 0.42 for coil overs. For anyone with a little time to burn check this post.
https://rennlist.com/forums/showpost...8&postcount=26
https://rennlist.com/forums/showpost...8&postcount=26
10-30-2008, 12:16 AM
#37
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The rear is 0.42 for coil overs. For anyone with a little time to burn check this post.
https://rennlist.com/forums/showpost...8&postcount=26
https://rennlist.com/forums/showpost...8&postcount=26
10-30-2008, 01:11 AM
#38
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That is actually an email Karl sent to me when I was trying to calculate my rates. I don't lay claim to understand it fully, but I'm happy to post it from time to time under just such circumstances. If I was to do a track focused road/track car again, I'd go slightly higher rates than I've currently got now. For a track only car I'd be looking at somewhere near 1000lb/in +/-.
10-30-2008, 05:49 AM
#40
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618lb/in f and 708lb/in rear. All the info in that email of Karl's is about my setup. Having said that, I noticed on my front springs today it said 0-170. Being of German origin they measure in Newton metres but I thought mine were 110Nm so I'm not sure now. In that 110 is = to 618lb/in I can't believe that I have 170Nm. I'll have to check this out a little more.
10-30-2008, 06:17 AM
#42
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Perhaps, but where does the 0 come from? Fully compressed?
10-30-2008, 09:44 AM
#44
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The rear is 0.42 for coil overs. For anyone with a little time to burn check this post.
https://rennlist.com/forums/showpost...8&postcount=26
https://rennlist.com/forums/showpost...8&postcount=26
The rear equation is based on a motion ratio of .65, and .65 squared is .42:
Effective spring rate at the rear wheel = (.42 * actual spring rate) + (effective tbar rate)
The front equation is based on a motion ratio of .91, and .91 squared is .83:
Effective spring rate at the front wheel = .83 * actual spring rate
Effective tbar rates are as follows:
07-22-2009, 05:39 PM
#45
Rennlist Member
So I wonder if the OP changed his setup and if so what to?
Good thread.
Good thread.