Rear damper travel; Rear passenger packaging

[marellasunny]

I am quite uncertain as to why the rear damper is inclined at a angle to the inside of the car. By doing so, does one ensure for rear wheel travel to be along a curved up/down path? i.e I am perplexed as most of the modern rear suspensions are multi-link and have their dampers inclined → This makes it hard to package the rear passengers as they have to be placed closer towards the centre. To visualize my question better, I have attached a catia file that I have drawn.

2. I am quite worried if there is enough 'play' for the rear dampers and that their travel does not intersect with the rear passenger seating position. Please give your views as to the optimal distance between rear damper strut point and seating position.

 

[Greg Bernhardt]

I'm sorry you are not finding help at the moment. Is there any additional information you can share with us?

 

[marellasunny]

Actually, not much more to give than the diagram I have attached. I was hoping for some insights into rear damper packaging, for example:

1.Is the rear damper placed before/after the lower A-arm?

2.How much laterally to the centre do I place the damper?

 

[jack action]

Dampers are usually inclined such that the angle between the A-arm and damper increases toward a right angle. This way the motion ratio (wheel displacement per damper displacement) increases as the wheel goes up and the damping coefficient at the wheel increases as well. That slows down the wheel faster and faster as the suspension goes towards its bump stop.

As to where is the optimal distance between damper and passenger, I think its quite irrelevant. It would more where is the optimal distance between damper and wheel. I think that most suspension designers want to keep them as close as possible such that the motion ratio is as close as possible to 1:1. This ensure the softest damper possible with a wide motion range. As the motion ratio increases, you have to work with very large forces moving with very small displacements.

Also, a damper can be placed almost anywhere with a little imagination: