Rear Shock Mounting Question?

[comegetsome2003]

im putting together my 82 GMC now for a play truck.....havent really spent much money on and am just mostly using spare parts that are laying around.....so far i have swapped the 355 out for a stout 468 that was in my Nova race car.....motor has been 6.30s(1/8th) mile in my car....built t350 trans....just swapped in a 12 bolt with 4.10s and tru-trac....needs some ideas or recommendations on how to mount the rear shocks....i have some Monroes i took off it that were mounted in stock location....truck is lowered 5 inches with a flip kit...gonna be street driven alittle and on 325/50 Nitto 555s....ill swap to some drag shocks....ive read that as straight up and down as i can get them will work best but id like a few opinions from somebody who has more experience than me at this....thanks in advance

[KQQL IT]

Cal tracs. My 73 wanted both shocks going in the same direction. Leaning toward the front at a 30° angle or so.

[vin63]

The primary reason for an angled rear shock mount configuration on a pick up is to yield a little more travel from a particular shock absorber part and to be vertical as possible to the travel…this is important for a street driven truck that will see widely varying loads. Ideally, for a drag race application, the shock should be mounted vertical for efficiency and repeatability (consistency). Here is kind of what I go by when setting up shocks/coil springs for customer projects:

Dampening Effectiveness

Vertical - 100% effective

10 degree angle- 98% effective

30 degree angle- 86% effective

45 degree angle- 70% effective

[Damien]

There is not a simple answer to this question. When you are making changes to a suspension you need to consider the entire suspension system. The type of suspension needs to be considered since leaf spring will react differently than ladder bar or four link suspensions. Leaf springs will wrap up under acceleration which if not controlled can cause wheel hop. The type of shocks and valving you are using also needs be taken into consideration. The OE replacement Monroe shocks are designed to give a "good" ride for a stock weight, street driven truck. These shocks are going to have a soft compression and firmer rebound valving to give good control on the street. As Vin63 stated, mounting the shocks at more of an angle will reduce the effectiveness. Moving these same shocks to a more vertical angle will effectively stiffen the valving. Reducing the weight of the truck will also make these shocks feel stiffer. If the compression valving is too stiff performance and ride quality will suffer. Having a firmer rebound will help handling and tie the truck down. If you have an adjustable shock you can tune the valving and the angle of the shock becomes less important.

Angling the shocks forward or backwards will help control wheel hop and brake hop. Angling the shocks toward the center of the vehicle helps with roll stability. Having the shocks mounted vertically is the easiest way to mount them, but not always the best choice depending on the application.

[hotrod 80]

Originally Posted by Damien

There is not a simple answer to this question. When you are making changes to a suspension you need to consider the entire suspension system. The type of suspension needs to be considered since leaf spring will react differently than ladder bar or four link suspensions. Leaf springs will wrap up under acceleration which if not controlled can cause wheel hop. The type of shocks and valving you are using also needs be taken into consideration. The OE replacement Monroe shocks are designed to give a "good" ride for a stock weight, street driven truck. These shocks are going to have a soft compression and firmer rebound valving to give good control on the street. As Vin63 stated, mounting the shocks at more of an angle will reduce the effectiveness. Moving these same shocks to a more vertical angle will effectively stiffen the valving. Reducing the weight of the truck will also make these shocks feel stiffer. If the compression valving is too stiff performance and ride quality will suffer. Having a firmer rebound will help handling and tie the truck down. If you have an adjustable shock you can tune the valving and the angle of the shock becomes less important.

Angling the shocks forward or backwards will help control wheel hop and brake hop. Angling the shocks toward the center of the vehicle helps with roll stability. Having the shocks mounted vertically is the easiest way to mount them, but not always the best choice depending on the application.

Well said , and i would consider a Rancho or Calvert 9 wayy adjustable for this aplication . Set on one setting for the track , then as said up top adjusted to soften compression for the street / ride quality . I might even consider the onboard air controller to keep from having to get under the truck .