gearwhine
NAXJA Forum User
- Location
- Denver, CO
OK, here's the deal. I've been searching all over trying to find characteristics of leaf spring suspensions. The majority of the things I've found online are either 4 links, or independent suspensions. BTW, I'm focusing on rear leaf systems.
I've sesarched for dynamics, calculations, etc, using leaf as the main term, and then using hotchkiss as another main term. I really can't find much.
I got directed to a guy that last night TPInjeep from pirate board, and chatted with him for a while about it. All he relaly knew was that when he added a traction bar, he gained anti-squate, making the rear lift under hard accel.
I'm wondering about plain old leaves, without a traction bar, then I got him wondering about it, and he found this thread on pirate, that I must've missed.
link
PIG gives an equation for it up top, but Ed Stevens makes good points at the bottom that deem it to not be a very good equation.
Ed also says that the draggers raise the front main eye up to REDUCE AS%. This is confusing me because I just read in a book (chassis engineering by Herb adams[I think this is a horrible book BTW, I don't know if I can trust what he says]) that antisquat is RAISED by moving the eye up. Then it's said the lowering or raising the rear eye will do the same thing, but to a much lesser degree? Why is that? So to sum up this paragraph, what's the relationship between the eye heights, shackle length, antisquat, and roll center?
I also found this which explain it a little more.
link
Go to pages 10 and 11, 10 starts to explain it, page 11 has the picture representing it.
If you can't read it(too small), right click it and drag it off of the internet explorer window, adn release, it will bring it up in another window, and then on the bottom right of a picture a button will magically appear to enlarge the picture, then it's all clear to read. )
What is the instantaneous center? (point C in that pic) They explain that as 3/8 the length of the the front half of the spring coming FROM the axle centerline. Is that the imaginary pivot point for where the axle rotates around? Then from that, you can get the roll axis...I read in ed stevens post in the "tracbarless suspensions" post that each suspensiont front and rear has a seperate roll axis, but I've also read about a roll axis going from the front to the rear...which is which, and which is more important?....I'm getting confused here, I will stop and hopefully someone can explain this.
And yes, even if leaf springs suck, I want to know this because I don't see a point in a link suspension if I can learn how to fine tune a leaf suspension to do exactly what I want it to do. I want to know what kind of effects heights, angles, etc has on how a leaf suspension works...it's gotta have hidden complexities to it somwhere.
Thanks a lot _nicko_
I've sesarched for dynamics, calculations, etc, using leaf as the main term, and then using hotchkiss as another main term. I really can't find much.
I got directed to a guy that last night TPInjeep from pirate board, and chatted with him for a while about it. All he relaly knew was that when he added a traction bar, he gained anti-squate, making the rear lift under hard accel.
I'm wondering about plain old leaves, without a traction bar, then I got him wondering about it, and he found this thread on pirate, that I must've missed.
link
PIG gives an equation for it up top, but Ed Stevens makes good points at the bottom that deem it to not be a very good equation.
Ed also says that the draggers raise the front main eye up to REDUCE AS%. This is confusing me because I just read in a book (chassis engineering by Herb adams[I think this is a horrible book BTW, I don't know if I can trust what he says]) that antisquat is RAISED by moving the eye up. Then it's said the lowering or raising the rear eye will do the same thing, but to a much lesser degree? Why is that? So to sum up this paragraph, what's the relationship between the eye heights, shackle length, antisquat, and roll center?
I also found this which explain it a little more.
link
Go to pages 10 and 11, 10 starts to explain it, page 11 has the picture representing it.
If you can't read it(too small), right click it and drag it off of the internet explorer window, adn release, it will bring it up in another window, and then on the bottom right of a picture a button will magically appear to enlarge the picture, then it's all clear to read. )
What is the instantaneous center? (point C in that pic) They explain that as 3/8 the length of the the front half of the spring coming FROM the axle centerline. Is that the imaginary pivot point for where the axle rotates around? Then from that, you can get the roll axis...I read in ed stevens post in the "tracbarless suspensions" post that each suspensiont front and rear has a seperate roll axis, but I've also read about a roll axis going from the front to the rear...which is which, and which is more important?....I'm getting confused here, I will stop and hopefully someone can explain this.
And yes, even if leaf springs suck, I want to know this because I don't see a point in a link suspension if I can learn how to fine tune a leaf suspension to do exactly what I want it to do. I want to know what kind of effects heights, angles, etc has on how a leaf suspension works...it's gotta have hidden complexities to it somwhere.
Thanks a lot _nicko_