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Author Topic:   Pull bar springs?
dirtracer14
Member
posted April 21, 2001 07:58 PM
Do pull bar springs get weak? I have 2 1000 pnd springs on a dual spring rod and it is bottoming out? I also have a 76 next to the 90/10 and it is still bottoming out. Is there anyway to check this without racing it like if you drive it around should it be bottoming out just driving around the pits? Any and all help would be great!!Thanks.


bogged
Member
posted April 22, 2001 09:03 AM
while the spring can take a set that will cause the length to change, it is unlikely to change the rate unless it is broken. if you are bottoming out a 1000 lb. spring running on the IMCA tire you must have some ALOT of forward bite. if the bite is not there check to make sure the rod is not trying to hold up the car in some way.


dirtracer14
Member
posted April 22, 2001 11:09 AM
We run the hossier A40 and i have 2 1000 pnd springs I have pulled the rod out and the rear stays?


Racer 10
Member
posted April 22, 2001 05:07 PM
quote:
Originally posted by dirtracer14:
Do pull bar springs get weak? I have 2 1000 pnd springs on a dual spring rod and it is bottoming out? I also have a 76 next to the 90/10 and it is still bottoming out. Is there anyway to check this without racing it like if you drive it around should it be bottoming out just driving around the pits? Any and all help would be great!!Thanks.

If you stack two 1000 lbs. springs you end up with a 500 lbs. spring rate usualy if two springs are stacked there is one that is extremely heavy just too keep some compliance without bottoming out the other is slightly heavier than the rate you desire. Any time you stack two springs togather you have to add thier rate togather and divide by 2 to get the true rate. Good luck



bogged
Member
posted April 22, 2001 06:37 PM
racer10 is right if the springs are stacked together the overall rate is (spring(1)*spring(2))/(spring(1)+spring(2)). sorry i totally missed the 2 spring part.


dirtracer14
Member
posted April 22, 2001 07:25 PM
So the total is 1000 after i add the 2 together then devide by 2. So should i be able to bottom them both out or is one or both bad? How much travel should you get on a tacky or kinda dry track?


dirtracer14
Member
posted April 22, 2001 07:51 PM
I had to do it jammin!!


Racer 10
Member
posted April 23, 2001 05:25 PM
quote:
Originally posted by dirtracer14:
So the total is 1000 after i add the 2 together then devide by 2. So should i be able to bottom them both out or is one or both bad? How much travel should you get on a tacky or kinda dry track?

Sorry my math wasn't quite right

(Spring #1 X Spring #2)
_____________________
(Spring #1 + Spring #2)

In your case 1000 X 1000 =1,000000
1000 + 1000 =2000

1,000000 divided by 2000 = 500 Sorry for the confusion probably something that ends up around 1000 would be a good place to start 2"-2.5" of travel would be a nice place to start. Good Luck


[This message has been edited by Racer 10 (edited April 23, 2001).]

jammin
Administrator
posted April 23, 2001 09:01 PM
Hey! Where are those Dirt Forum stickers at? LOL