Coil-over mounting angle 1

[Gmachine3]

Coil-overs are typically mounted straight up for straight line performance,e.g., Pro-street, drag strip. What are the guidelines for mounting coil-over shocks for handling through the curves? From researching various enthusiasts boards I have found angles recommended from 7 to over 30 degrees. I have also found various methods recommended for determining the best angle, however when applying the different methods I come up with greatly different coil-over mounting angles. Granted there are location and packaging restraints, but is there rule of thumb or optimal angle to shoot for?

Thanks

 

[patprimmer]

i worked on a very successfull of road race car.

On this, we set the shocks as near as we could to perpendicular to the axis of the suspension arm at 1/2 travel, with the bottom of the shock as far outboard as we could reasonably do and the top of the shock set so as to just maintain minimum tyre clearance through out the range of travel.

We followed two basic principles.
Keep the shocks as in line with the direction of motion of the suspension arm as possible
Keep the shocks as close to the wheel as possible

Regards
pat

 

[mloew]

Gmachine3,

This topic has been covered before in some detail. Sift through the following threads fore some more information:

Shock friction thread800-57725
Designing a SLA front suspension thread800-55631

Good luck with your design.



Best regards,

Matthew Ian Loew

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[Gmachine3]

Thanks for the input guys. The information and treads were very helpful. Like anything else, there is a lot more to it when you start digging beyond conventional wisdom.

Thanks again
Lee

 

[Joest]

Assuming the suspension does not uses leaf spring with rubber bushing and is positively controlled by rigid linkage then the best mounting angle seems to be very close to vertical and as close to the wheel as possible at ride height. This angle and location give the full benefit of the spring and damping rates. If a shock is mounted at, say 30 degree, the shock is only cos(30) effective or 0.866. To compensate stiffer springs and damper rate are required which typically increases weight.

 

[musclemotor]

In NASCAR (Circle Track Racers) shock angle usually runs 10-45 Degrees with average being about 20. One thing that is important on coil-over shocks, spring rates should be changed (increased) when shock angle is increased. An example range would be 5% increase for 10 degrees and 100% increase on 45 Degrees. For more info look at this website

http://www.stockcarproducts.com/pstech8.htm

Good luck racing,
Grib