The 'Tools", What do they do?

[BoilerIMS]

Gents, please keep this thread going! The uber-dorky engineer in me is loving this.

[chuck34]

Gents, please keep this thread going! The uber-dorky engineer in me is loving this.

Dorks of the world unite!!

Dyslexics of the world untie!!

Sorry, hope that doesn't offend anyone, I just find it funny. :-)

[garyshell]

Dorks of the world unite!!

Dyslexics of the world untie!!

Sorry, hope that doesn't offend anyone, I just find it funny. :-)

Screw political correctness, it IS funny.

Gary

[Hoop-98]

The spring angle only applies to McPherson struts, I think? And then it really sort of acts like the motion ratio. To me at least I always think about motion ratio as sort of like taking the spring off, jacking the hub up by x amount, and measuring the displacement between spring perches. I would do this at a fairly fine resolution so that you can capture any non-linearities.

The spring angle is illustrated above.

There are lots of calculators where you put in D1,D2 and angles and or course with a rising rate suspension it as always, gets more complicated.


rh

[PA Rick]

The spring angle is illustrated above.

There are lots of calculators where you put in D1,D2 and angles and or course with a rising rate suspension it as always, gets more complicated.


rh

The d1 d2 ratio and spring angle determine the actual spring rate(the actual rate of the spring itself) vs vehicle spring rate. The important ratio is upper A arm to lower A arm length which compensates for camber changes as the car rolls. In a McPherson strut suspension the spring/strut angle sort of acts the same way.

[Hoop-98]

The d1 d2 ratio and spring angle determine the actual spring rate(the actual rate of the spring itself) vs vehicle spring rate. The important ratio is upper A arm to lower A arm length which compensates for camber changes as the car rolls. In a McPherson strut suspension the spring/strut angle sort of acts the same way.

I would add that the angles are most important in controlling the camber curve. With the above illustration you can see that due to the angles the suspension will curve negative in compression and positive in extension.


rh

[chuck34]

The spring angle is illustrated above.

There are lots of calculators where you put in D1,D2 and angles and or course with a rising rate suspension it as always, gets more complicated.


rh

I would have to look "under the hood" of your calculator, but I would suspect they use the D1, D2 to figure motion ratios. So perhaps I was a bit "sloppy" in my earlier explaination. I wasn't thinking about this type of suspension, I was thinking more along the lines of modern IndyCar/Sports car types with bell cranks, etc.

[chuck34]

The d1 d2 ratio and spring angle determine the actual spring rate(the actual rate of the spring itself) vs vehicle spring rate. The important ratio is upper A arm to lower A arm length which compensates for camber changes as the car rolls. In a McPherson strut suspension the spring/strut angle sort of acts the same way.

What you are talking about with teh upper/lower arm angles is called camber recovery. And in a strut suspension there is very little camber recovery. Since the upper arm is basically the body, the camber pretty much just "rolls over" with the body. There is a bit of recovery because of the angle of the lower arm/spring, but not much.

[Hoop-98]

I would have to look "under the hood" of your calculator, but I would suspect they use the D1, D2 to figure motion ratios. So perhaps I was a bit "sloppy" in my earlier explaination. I wasn't thinking about this type of suspension, I was thinking more along the lines of modern IndyCar/Sports car types with bell cranks, etc.

If you wanna peek ;P



rh

[Hoop-98]

What you are talking about with teh upper/lower arm angles is called camber recovery. And in a strut suspension there is very little camber recovery. Since the upper arm is basically the body, the camber pretty much just "rolls over" with the body. There is a bit of recovery because of the angle of the lower arm/spring, but not much.

The Key with a fixed mount strut suspension is that the lower arm be near parallel to the ground in full compression.



Mustang Strut ======================Short/Long Arm

I have always called this camber gain btw.

rh