Thanks Greg,that setup will be an easy install for me if I dont have to move the quickener.
All UTV's Figuring Dual Rate springs
- Thread starter Wild Earp
- Start date
Ok, so I took Steve's (MakinTrax) advice, and went with the "springs dont lie" method. After doing the measurements and trying every calculator out there, and getting all sorts of screwy numbers... I measured how much the spring was compressing at ride height. I tried it will a few different spring weights (at zero preload), and got the exact same number every time. 375 lbs of force on the front spring, 562.5 lbs of force on the rear.
With 250 lb springs on the rear, I was getting 28% Droop. So doing the math, I should get 47% Droop with a 150lb Primary rate in the back, and a 100 lb Primary rate in the front. Its all starting to make sense now. Rogs numbers came out to a 95 primary (with my car being significantly heavier).
So now I just need to figure out what I want my secondary to be, and Ill be easily able to figure out the top spring to get the Primary/ride height I want. So now the question is, whats the best way to use the force numbers I have to find a starting point for my bottom spring?
If I have 1.5 times as much force on the spring in the back, would a good starting point be a spring that is 1.5x heavier than the front? Ie 250 F/ 375R. Or is this just going to change with tuning anyways, so it doesnt make sense to figure out the math at this point anyways.
Thanks for your help guys. Im going to run the single springs for thanksgiving (although they are a little stiff, at only 28% droop, but Ill be running desert anyways so it will be ok), and then dive into spring collecting in December!
With 250 lb springs on the rear, I was getting 28% Droop. So doing the math, I should get 47% Droop with a 150lb Primary rate in the back, and a 100 lb Primary rate in the front. Its all starting to make sense now. Rogs numbers came out to a 95 primary (with my car being significantly heavier).
So now I just need to figure out what I want my secondary to be, and Ill be easily able to figure out the top spring to get the Primary/ride height I want. So now the question is, whats the best way to use the force numbers I have to find a starting point for my bottom spring?
If I have 1.5 times as much force on the spring in the back, would a good starting point be a spring that is 1.5x heavier than the front? Ie 250 F/ 375R. Or is this just going to change with tuning anyways, so it doesnt make sense to figure out the math at this point anyways.
Thanks for your help guys. Im going to run the single springs for thanksgiving (although they are a little stiff, at only 28% droop, but Ill be running desert anyways so it will be ok), and then dive into spring collecting in December!
Way to go Ben! Like I said the springs never lie. I suggest you focus on each end of the car seperately. Don't worry about the ratio or % front to rear. See those numbers the springs give you is what the spring is bearing. It is not the weight of the car. So if you make each end sprung correctly based upon your spring weight numbers the balance will be there.
I ran some numbers for you and think these are good starting point for rates to give you the sag you want with a small amount of preload and yet a good rate to step-up to.
Front 150/225 primary rate 90# or 175/200 primary rate 93. Rate needed w/zero preload 94#
Rear 250/300 primary rate 136 or 225/350 primary rate 136. Rate needed w/zero preload 140#
Hope that helps Ben.
I ran some numbers for you and think these are good starting point for rates to give you the sag you want with a small amount of preload and yet a good rate to step-up to.
Front 150/225 primary rate 90# or 175/200 primary rate 93. Rate needed w/zero preload 94#
Rear 250/300 primary rate 136 or 225/350 primary rate 136. Rate needed w/zero preload 140#
Hope that helps Ben.
Thanks Steve, that helps a lot!
Im putting the car back together now, and will shoot some pics next week at the river.
Im putting the car back together now, and will shoot some pics next week at the river.
see, I was not far off really. 
once a base setup is there, you will still need to run it and test it, to see where your at, each preference can be different.
remember the secondary is going to do the work, (mostly) so when testing you prob won't change the uppers if ride height is correct, until you want to run dez, but you could then also preload them more.
once a base setup is there, you will still need to run it and test it, to see where your at, each preference can be different.
remember the secondary is going to do the work, (mostly) so when testing you prob won't change the uppers if ride height is correct, until you want to run dez, but you could then also preload them more.
Thanks Rog!see, I was not far off really.
once a base setup is there, you will still need to run it and test it, to see where your at, each preference can be different.
remember the secondary is going to do the work, (mostly) so when testing you prob won't change the uppers if ride height is correct, until you want to run dez, but you could then also preload them more.