For asphalt Late Model racing, ride heights are becoming a thing of the past. Many tracks and sanctions are relaxing the ride height rule because of the bump setups that cause the car to go far below the usual standard. But does that mean a team has to disregard ride heights when they setup the car? No way. Ride heights will always be important, maybe more so now than ever, and we’ll tell you why.

We stress the importance of establishing a baseline for your setup. The term “setup” encompasses many different settings on the car. One of the areas of concern are the angles of the control arms and positions of the moment centers, front and rear.
Every team needs to establish ride heights for their car no matter which class you will run. This baseline height will dictate many of the other settings and going back to a known height will help you with changes you might want to make to the car from time to time.
What Heights Do I Want? – For manufactured race cars, the car builder usually has established a set of ride heights for you to use. We would recommend using those ride heights because they are the basis for every suggestion for mounting points that the builder provides.
If you don’t have your ride heights established, or don’t know what to set them at, here are the tried and true heights that racers have used for years. The LF is usually the lowest corner and is set at 4.0” if the ride height rules have a minimum of 4.0” for any part of the chassis. You should cheat up 1/8” or even ¼” to make sure you don’t get thrown out of tech for a low car after the race.
Moving along, the RF corner is usually ¼” to ½” higher than the LF corner and the LR corner is the same. The RR corner is the highest at from 4 ½” to 5” in height. Like we said, these are tried and true ride heights. It doesn’t mean you have to abide by these numbers.
I think the traditional setups caused the most travel in the RR corner, and so that corner was set higher in ride height to compensate for that travel. With modern day setups using a much stiffer RR springs, the travel amount has gone down considerably. Where we used to see 3.5 to 4.0 inches of travel in the RR, we now see 2.0 – 2.5 inches or less.
With the RF traveling 3.0 – 3.5 inches, we will still have a rake in the attitude of the chassis even if we level out the right side ride heights. Then the rear of the car will be a good ½” lower which lowers the overall race car Center of Gravity.

Which Settings Are Depend On Ride Height? – Once we establish our ride heights, we need to establish certain chassis settings in relation to those ride heights. We might have recorded heights off the floor for things such as, the lower control arm chassis mounts for the front end. We might have set our front trailing arm mounts in the rear suspension by using measurements off the floor. We need to re-think those measurements now.
If you haven’t thought about it before, when making setup changes, like going from conventional setups to bump setups, all of the angles will be much different for the control arms and suspension links. Angles that worked before now don’t work very well.
Some of the frustration you might be having with the new setup could be traced to improper link angles. For example, if we might have always set the RR trailing arm angle at 4.0 degrees because the RR shock travel was 3.5 to 4.0 inches. When the travel changed to under 2.0 inches, that angle must also change to under 2.0 degrees or you’ll end up with a lot of loose rear steer.
With the new stiffer RR spring rate, the high angle pushes the RR wheel back and the front mount won’t travel enough to bring the RR wheel back to its static position and the wheel will stay back some amount steering the rear to the right.
The overall travel in the rear will diminish also. So, any angle you put into the LR link to help produce rear steer under acceleration and squat won’t produce the same effect. You might need to put more angle in that link to compensate for less movement.
Front Considerations For Ride Height – At the front, we have some exciting things to think about. For the conventional setups, life goes on as usual, but for the bump setups, we might be able to rethink how we always did things.
We all know by now that the front geometry is important and that it dictates the control arm angles in the AA-arm suspension. What we have established through testing is that the ideal control arm angles will produce less camber change to keep the contact patches consistent.
One fact about bump setups is that the chassis moves very little vertically, or in roll for that matter, when the front is on the bumps with their very high spring rates. So, in that very small window of movement, if we set control arm angles that will produce very little, or no, camber change, our cars should like that, and they do.
If we put the car at the on-track ride height and then study the camber change, we might re-think our control arm angles, at that height. If we make changes, then when the car is at the higher static ride height in the shop or in the pits, the arm angles will look much different, but why do we care about that. All we really care about is where the angles are when on the track and on the bumps. Those setups must stay on the bumps in order for this to work.


Experimentation – I did a little experimentation with control arm angles and ride heights. Here is what I found out. This was really interesting. I took a typical asphalt late model front AA-arm geometry layout like we use on the current bump setups and noted the Moment Center location at ride height and again at 3.5” of dive and 1.0 deg. of roll.
The upper control arm angles are: Left Upper at 28 deg. and the Right Upper at 12 deg. and the Left Lower angle is 2.5 deg. and the Right Lower angle is at 1.5 deg. At ride height, we have a MC height of 3.2 and a width of negative 13.1” (left of centerline). When I dive and roll this car, I get a MC of 1.0” in height and 13.1 inches to the right of centerline.
In our research, the upper control arm angles that produce the least camber change put the MC to the left of centerline, much like our static MC. But with the MC location after dive and roll, the car ends up with the worst angles for camber change. So, any movement of the car vertically will end up causing a change in camber the car won’t like.
What I end up with is this, what if I put the car at the attitude it will be racing at, down on the bumps, and then set the same upper control arm angles as they were in the example at ride height? What if down on the bumps I set the LU angle at 28 deg. and the RU angle at 12 deg.?

The lower angles cannot be changed due to the clearance between the lower ball joint and the wheel, plus there is no room to raise the inner chassis mounts. Now, with just these upper arm changes, won’t my camber change be much better? Yes it will.
As to camber change while on the bumps, a quarter inch change in ride height, from 3.5” dive to 3.75” dive with the old system yielded a 0.8 degree camber change in the left wheel and a 0.6 degree change in the right wheel. That’s a lot for that small a ride height change. On the other hand, with the new upper angles, the left wheel only changed 0.2 deg. of camber and the right wheel didn’t change camber at all. I think we are on to something here.
Another interesting thing about this test is that the MC height was 1.0 inch above ground originally and went to 7.4 inches below ground with the new upper angles. We know that the height of the MC is directly related to chassis stiffness, so a longer moment arm would make the front more efficient, making it turn better.
Conclusion – Ride heights are important in keeping track of our link angles and keeping everything consistent. But could we now look at the ride heights in context to how we race the car? It’s food for thought.
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