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What are the spring rates of all the C7 springs

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What are the spring rates of all the C7 springs

 
Old 09-07-2015, 01:08 PM
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mustclime
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Default What are the spring rates of all the C7 springs

I also found out there are different part numbers for the springs on the Stingray, Stingray auto, Z51, Z51 auto, Z51 magride, Z51 magride auto, Z06, Z06 auto, Z06-07 and the Z06-07 auto...........That is a different part number for each spring(F&R) for each level.....that's 14-16 different springs that may or may not have different spring rates...that is some crazy suspension tuning....The rub is no one knows what the spring rates are for these springs.

BTW...springs are less than $200 and they use one spring for both sides....so for about $400 you can change your springs....if you knew what spring rates you had.

In the interest of track tuning, I would like to know what the spring rates are for each part number....

BTW, suspensions are tuned around the tires. All the guys that are taking their run-flats off in favor of something stickie, you just screwed up your suspension tune.....
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Old 09-08-2015, 07:18 AM
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descartesfool
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It would be best to know the wheel rate which is the spring rate at the wheel, and to also ask for the front and rear motion ratios for each car to go along with the spring rate so one can calculate the wheel rate.
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Old 09-08-2015, 08:48 PM
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Motion ratios(MR) are easy...move the wheel 10cm, how much does the shock move? How much does the spring perch move?

WR = (spring rate) ( MR^2)

then you can get the suspension frequency(SF)

Now brake out the scales and get your sprung weight (with your butt in the seat)

SF = (187.8)(SQRT(WR/SPRUNG WEIGHT))

Now you have to convert the SF to Hertz(Hz). Here is the formula for that....

Hz=SF/60

Once you have the Hz's, you can now start looking at what each end of the car is doing and how you want it to change....plug in different spring rates and let the numbers guide you...

All this car math needs the spring rates....no spring rates= no car math and with no car math you are just throwing darts in the dark and hoping to get the right combo that works........

Wouldn't be nice to get all these numbers and be able to say...yup, with 315's on the rear and 275's on the front(sub 200 wr tires), you need a front Z06-07 auto trans spring on the front and at z51 mag ride manual rear spring to get to the sweet spot of 2.5 Hz front and 2.3 Hz rear...and it will only cause minor internal bleeding on a rough course....(disclamer...I have no idea what the spring rates are so I can not say any of that)

Instead we have a bunch of guys just throwing parts at the cars and saying "it feels good"....Are there any forums out there where people are really tuning Stingrays?
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Old 09-08-2015, 10:51 PM
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Spring rates are useless without motion ratios. Motion ratios are hard to measure precisely if you have actually done it. Since one squares the motion ratio, any error in the motion ratio makes a large change in the wheel rate. It is much better to get the motion ratio from the guys who designed the suspension. Tires couldn't car less about spring rates. All they see are the wheel rates.
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Old 09-09-2015, 01:22 AM
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I have never done it with a vette...strut cars are easy....get the car in the air...remove the springs(loosen all the suspension bolts so the inner sleeves on the bushings do not limit suspension movement) and set up your markers......( I love to use the lazes line markers for leveling stuff in the home but I have done it with string)...with strut cars you just put zip ties in the strut shafts...move the wheel, measure how much it moves the zip tie on the shock....boom, you are done.............not sure on a vette if you measure the spring perch location movement or the shock moment...but thats no big deal, a motion ratio is for any amount one thing moves, the other thing moves this amount. Run the cycle 5-10 times and you can really nail down your number....good way to spend an afternoon and kill some beer...Its the spring rates, thats are hard part.....And yes, I have done it....
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Old 07-15-2018, 02:23 PM
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Bumping an old thread. Did anyone ever have any success in finding the spring rates and motion ratios? I'm playing around with math channels and the suspension movement data in Pi Toolbox but spring rates in particular would be very useful. I'm looking for the C7 ZR1 but will take anything as an estimate for now.
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