Visit The Dirt Forum for More Information

Author Topic:   Coil spring tester
RACEINMUD
Member
posted March 23, 2004 12:40 PM
Hey, I have been loaned a spring tester and need some help. Not sure how to get the correct spring rate. On this one, you place the spring on the base and screw the top down to compress spring and read the gauge. Anyone know how far to turn down to get a reading. The more I turn down the top the higher the reading goes with no end in sight. Any help would be appreciated. Thanks, Race I would ask the owner be he is not around.


Flanndad
Member
posted March 23, 2004 12:57 PM
Hopefully someone with more insight will help, but i believe that springs are measured at 1" compression.


dirtbuster
Member
posted March 23, 2004 01:02 PM
i seem to remember reading about this and the article said to compress the spring 1" take a reading then compress it another inch. Subtract the first number from the second and you have your rate per inch.


zeroracing
Member
posted March 23, 2004 01:43 PM
I second that. Spring rate is the weight required to compress the spring 1". For example, if you stacked 800 pounds on top of a 10" tall spring rated at 800 pounds, it will compress 1".


RACEINMUD
Member
posted March 23, 2004 05:05 PM
Thank you very much! Race


sideways
Member
posted March 23, 2004 06:27 PM
No they are not exact but like anything else in racing as long as you use the same one ever time then it is all linear.The way we do it is put pressure on the spring til the needle just starts to move and then go 1" take a reading then go another 1" take a reading and like all have said subracted the 2.We always do the springs at least twice in a row.Then mark.There are about 5 or 6 of us use the same one so there all linear incase we borrow a spring.Hope this helps.


c21
Member
posted March 24, 2004 09:33 AM
you can also do this (extremely accurately) in your shop press using your electronic scales.

If the spring is "open" at one end (like most fronts are) you may want to set a lower control arm on the pad and THEN the spring.

pump the shop press untill the spring is fully seated (top and bottom), take a measurement AND zero the scale. pump the press untill you get another inch ..... take your reading.

coil springs are marginally non-linear by their nature (slightly digressive, since rate is inversely proportional to "coils per inch") .... however, the difference between the 1st second and 3rd inch is normally fairly insignificant.

You should find that most coils end up VERY close to the original manufactures rate (it's pretty hard to F up a coil spring).

c21

Back to the Archives