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Dynamic Distribution Calculator

Here is the next tool from TCE to help buyers with their brake purchase; a Dynamic Weight Distribution calculator. What does that mean and how does it work?

Dynamic distibution takes into account the weight shift of the vehicle during a braking event. As we know, the weight is shifted forward as we slow a vehicle and we can then use that data to help evaluate the choices of front and rear braking to meet that dynamic shift. This leads us to the next step of Brake Bias- Dynamic Bias.

NOTE: While this program does show weight shift, it is not to be considered a fully dynamic brake bias calculator. The program does not yet take into account proportioning issues incorporated into the stock braking systems. To be truly dynamic it would require a review of line pressures and torque values.

To use this calculator you'll need some more technical data than we require in the Bias Calculator alone. Again, TCE has provided this page with an example to use to evaluate the whys and hows of this process.

To best use the calculator you will need the following information:

Front and rear vehicle weight. This is the weight of your vehicle as measured under each end of your car on a flat surface. This is often done on a scale platform. If you do not have a scale platform to work from you might find some of this data in either the service manual, promotional materials, or even the door sticker.
The wheelbase of the car. This is the center to center distance front to rear wheel. Easy to do with a tape measure or you can review paperwork again as well.
Cg Height- Center of Gravity placement. This one is tough to do. The Cg is the center point of weight rotation of the vehicle. In short; a point off the ground where if you could stand all weight of the car would be equally displaced. If you need more indepth info on this do a Google search and review the article from LongacreRacing.com or other. For our purpose we'll use a simple value such as 20".
Braking force in G. This is an inertia force measurement equal to the total weight of the vehicle; 1G equals 3200lbs for example and 2G equals 6400lbs. Most street cars can generate a G load of about 1.2 in the most severe braking with modest tires. In some cases racing vehicle can exceed 1.5 or higher. For the average street stop however a value of perhaps .5-.7 would prove a rather significantly hard stop.

With your cars data you can now enter it into the calculator and see how the % of weight shifts with brake application. With this done you can now compare this % front to rear to that of the Brake Bias Calculator.

Front weight static:
Rear weight static:
Total Vehicle weight lbs.:
% of Front weight:
CG Height- Inches:
Wheelbase- Inches:
Braking Force in 'G':
Front Weight Dynamic:
Rear Weight Dynamic:
% of Front Weight Dynamic:

So what is to be learned here? The purpose of the Dynamic Distribution Calculator is to use this with the Bias Calculator to estimate the required mix of front and rear brake torque or Dynamic Bias of a vehicle. This data can help aide in the selection of parts used.

For example; if your plans call for a massive front and rear brake kit change and your static bias data from the other calculator net you a design of 60/40, here you can see what this does to your plan when put into use. If your vehicle is then capable of generating 1.2g with modest tires the dynamic shift will give an estimate as to how much rear brake bias is used at this point. It will be difficult to use 40% rear brake on a vehicle which then has only 23% rear weight. Finding the balance between how much can be exploited without causing a lock up condition is the goal.

*As always if you find fault with this tool or the wording used to describe any of it please contact TCE so we can discuss it. The goal here is to make these tools easy for everyone to understand.