Need a little help figuring something out

[Ron Sutton]

See, I knew you could do it Ron. Seriously...that is exactly what I was looking for when I asked the question. Thanks...

For the rest of the class, Ron has shown me the initial results of the diagrams like above using the measurements from my car and while digesting those, I was a bit lost in exactly what I was looking at, especially in regards to roll center. I figured best thing to do was ask and let Ron explain it to all of us in his own special way.

It is unbelievable to me how Ron can take something so complex and with words and a few pictures describe it in a way that makes it easy to understand. That is SO cool.

Hi Lance, Thanks for the kind words.

Explaining what roll centers are, how to calculate them & how to tune with them ... front & rear ... was a little easier than creating peace in the Middle East, but not by much.




That post got into the detail of roll centers (RC) ... but I think it's helpful for car guys & tuners to take several steps back & look at the big picture of handling ... to better understand the role of the RC with the rest of the car.

Total weight ... weight distribution front to rear ... and height of this weight (CG) act like a lever over the roll center. As discussed earlier, lowering the CG shortens that lever, as does raising the RC ... but works the tires less. Raising the CG lengthens that lever, as does lowering the RC ... and works the tires more.

Your goal is to move them both ... to the degree possible ... where you find the optimum balance of working the tires & roll angle. BUT ... and this is KEY ... modern day tuners do not use the RC height as the primary means of controlling roll angle. They use the suspension tuning items as their primary tools & the RC height as a secondary tool.

So to achieve the optimum balance of roll angle & working the 4 tires optimally ... this all has to work with your suspension ... springs, anti-roll bars & shocks ... and track width ... to end up at the optimum roll angle for your car & track application.

Hopefully, this brief overview, helps clarify roll centers place in the tuning picture.