Spring Rate Weight Distribution?

[Skye_Izumi]

I'm trying to get my head around spring rates and weight distribution, I wanted to ask if you set spring rates equal to the cars weight, example, say I got a car that ways 1000lb, with a weight distribution of 55/45 550lb front 450lb on rear.

Do I have to set spring rates equal to the car's weight distribution.

[RickKickem39]

No, the rate you want to choose will depend on the track, weather, vehicle, and any modifications and other tuning you have done to your vehicle. So its safe to say its difficult (or at least time-consuming) to tune correctly.

I watched a YouTube video that said the best way to tune it is (provided you have anti-roll bars) set the springs as soft as you can without the car bottoming out. Then adjust the anti-roll bars to keep the car flatter. He also said the best way to tune dampers along with this is to swap back and forth between the springs tab and dampers tab and adjust the top 2 sliders in each until they are in the same position.

[clairvoyantwolf]

It is important to remember that the suspension works as a system, springs, dampers, bars, etc. I notice a lot of tuning guides overemphasize bars as the fix to most issues or the main item to tune. That is technically incorrect.

The point of suspension, for racing purposes, is to keep the tires in the correct position as they move dynamically through their range of travel. The suspension HAS to move to generate grip. So you can have soft springs and hard bars or vice versa. Soft springs and bars would feel sloppy and hard springs and bars would generate no grip.

Springs generally speaking control how much the suspension moves. Now whether the tire is in its “happy place” as it moves depends on the car’s suspension design. As example a Miata is softer than the GT86 twins. However the double A arm design of the Miata means that the tire is kept in optimal position as the body moves compared to the strut suspension of the 86 twins which need to be stiffer for the same effect. Now increase the tire grip that equals more force, which means the car is rolling and pitching more than intended, which means the suspension needs to be stiffened to return the tire to its happy place.

That is the goal of car tuning. Optimum positioning of the tire.