26Likes3 racing new F1
08-09-2012, 11:44 PM
#3346
egad! what are you my mother? leave me alone!! You are really getting to be annoying!
08-10-2012, 06:55 AM
#3348
Typical 1/12 suspension diagram....
You'll notice that changing the upper link's angle/length will change the instant center, which will also change the RC, though in a more subtle fashion than moving lower arm. The lower link is non moving, but still is used the same as a dynamic lower arm for these purposes (it is just a horizontal line located on the lower pivot balls). Changing the height of the lower arm will also change the roll center, so changing the ride height, while crude, changes the RC. If there is a way to move the stationary lower link in relation to the chassis that will work also.
08-10-2012, 07:18 AM
#3349
Only thing is that this is a "static" diagram! Droop is the only way you can control the actual chassis roll , that is not a bad thing but nowhere near the same effect as the rear suspension. Droop becomes the lower arms and its virtually impossible to figure out how much the chassis is actually rolling because the springs are a huge part in this.
08-10-2012, 07:45 AM
#3350
I will prepare to be bombarded after I make this statement, but to be able to find a true instant center, you really need to have a lower arm that pivots, because you project the point in space of that lower pivot out to where it intersects the angle of the upper arm. In most instances you want the instant center outside the tire. The longer the instant center, the more stable, but less responsive the car will be. A kingpin front end moves vertically as opposed to swinging in an arc, so the million dollar question would be, does it have a true " roll center"
I agree.
08-10-2012, 08:17 AM
#3351
WOW, I expected at least a little pushback. Im not a gambler, but lets try another one. So with a pancar style design, that doesnt necessarily "roll" around a center, it is more critical to optimize the front to rear balance. On the FGX the primary method for this is rear droop. In saying that you need to look at the function of each component.
The shock or damper is for just that, damping, or controlling the motion. the springs primary function is to hold the chassis up off the ground, while its secondary function is to provide resistance against the dampening. IMO the first order of business on any chassis should be to get the weight transfer right. Shock length/droop adjustment should be the primary adjustment here.Damping should be adjusted based on the surface consistency of the track, and spring rates to adjust for the grip level of the track
The shock or damper is for just that, damping, or controlling the motion. the springs primary function is to hold the chassis up off the ground, while its secondary function is to provide resistance against the dampening. IMO the first order of business on any chassis should be to get the weight transfer right. Shock length/droop adjustment should be the primary adjustment here.Damping should be adjusted based on the surface consistency of the track, and spring rates to adjust for the grip level of the track
08-10-2012, 10:08 AM
#3352
WOW, I expected at least a little pushback. Im not a gambler, but lets try another one. So with a pancar style design, that doesnt necessarily "roll" around a center, it is more critical to optimize the front to rear balance. On the FGX the primary method for this is rear droop. In saying that you need to look at the function of each component.
The shock or damper is for just that, damping, or controlling the motion. the springs primary function is to hold the chassis up off the ground, while its secondary function is to provide resistance against the dampening. IMO the first order of business on any chassis should be to get the weight transfer right. Shock length/droop adjustment should be the primary adjustment here.Damping should be adjusted based on the surface consistency of the track, and spring rates to adjust for the grip level of the track
The shock or damper is for just that, damping, or controlling the motion. the springs primary function is to hold the chassis up off the ground, while its secondary function is to provide resistance against the dampening. IMO the first order of business on any chassis should be to get the weight transfer right. Shock length/droop adjustment should be the primary adjustment here.Damping should be adjusted based on the surface consistency of the track, and spring rates to adjust for the grip level of the track
This is one of the main reasons my Upper deck kit works so well because it has more lateral flex than the stock unit and that keeps the front tires on the ground.
08-10-2012, 11:33 AM
#3354
What little grey matter I have left is hurting. Isn't this a hobby. 
08-10-2012, 12:59 PM
#3356
Yes it is a hobby, but the days of building a kit and racing it are long gone. If you are going to race and be competitive, its the approach that you need to take. Trust me it took me a long time to understand all of this, but once I got a grasp on it, it made things a lot more fun, because i wasn't sitting around scratching my head when the car wasn't working
08-10-2012, 12:59 PM
#3357
Only thing is that this is a "static" diagram! Droop is the only way you can control the actual chassis roll , that is not a bad thing but nowhere near the same effect as the rear suspension. Droop becomes the lower arms and its virtually impossible to figure out how much the chassis is actually rolling because the springs are a huge part in this.
08-10-2012, 02:56 PM
#3358
I will prepare to be bombarded after I make this statement, but to be able to find a true instant center, you really need to have a lower arm that pivots, because you project the point in space of that lower pivot out to where it intersects the angle of the upper arm. In most instances you want the instant center outside the tire. The longer the instant center, the more stable, but less responsive the car will be. A kingpin front end moves vertically as opposed to swinging in an arc, so the million dollar question would be, does it have a true " roll center"
08-10-2012, 05:07 PM
#3360
the knuckle is in the same position on those diagrams, what happens when the knuckles moves up while the opposite side knuckle is limited because it cannot go down like a normal suspension would? Twisting the chassis is not what happens on the track. Not saying you are wrong but those sketches dont really tell us anything unless you have a way to simulate the upper arms moving. You only really get about 2mm or so of travel at most.