Traction Control

TMS Drag Pro 

How does it work?

The Non Self-Learning systems, like our Sportsman series, periodically compares the rate of acceleration of the driveshaft to an Adjustable Fixed Rate (AFR), known as Threshold.  If the DS RPM rate of change is in excess of that Threshold, then a correction is made.  The comparison is made every 1/8 of a turn of the driveshaft.

Basically, this Patented system looks for spikes in DS RPM that are caused by wheel slip.  If these spikes are large enough, then a correction is made, reducing the slip.

By adjusting the Threshold, the user can tune the system to correct larger slips, while not reacting to smaller, harmless, slips.  This means the user does not have to figure out the desired DS/Engine RPM and build a preset “Dot Plot” (anybody got a crystal ball?).

A typical 1/8th mile car turns the drive shaft about 300 times in a 660 ft. run. At 8 triggers per rev, that would be like building a “Dot Plot” w/ 2400 dots, and ¼ mile cars turn the drive shaft about 550-600 times in 1320 ft. run.  At 8 triggers per rev, that would be 4400-4800 dots.

Self-Learning systems, such as our Lite and Pro series, compare the rate of acceleration of the drive shaft to a calculated threshold value that is constantly updated based on the average of the previous measurements. This update occurs on every drive shaft revolution. So, if the last 1/8 of a turn of the drive shaft is faster than the average of the last full revolution, then a slip is detected. Through this very advanced Patented process, the system constantly accounts for track conditions, tire condition, etc. to constantly update the internal settings. These settings are updated as many as 800 times a second to keep the unit calibrated to exactly the right settings regardless of changing conditions.

Basically, the system learns the average rate of acceleration of the drive shaft, and if there is a sudden spike in RPM above that learned rate, then a correction is made.   With the Self-Learning feature, the user doesn’t have to try to figure out the DS RPM rate of change and set a “Threshold”, the system does it for you, every drive shaft revolution!

The user does have an adjustment referred to as “Mode” that sets the overall sensitivity of the system to make a correction based the extent of the tire. By adjusting the Mode, the user can tune the system to correct larger slips, while not reacting to smaller, harmless, slips. 

The biggest difference in our systems is the Speed and the Self-Learning capabilities.  Other systems “brag” that their TC works 10 times a second—our older systems worked 20 times a second, and while it would help “save a run”, it just was not fast enough to help you go faster.

The new systems (since Jan 2009) work every 1/8th  of a turn of the driveshaft. At 3000 RPM DS speed, a very critical area for tire slip, it measures the DS RPM 400 times a second, at 6000 DS RPM it measures 800 times a second! The system then processes those measurements 50 times a second (typically), and as fast as 100 times a second, to calculate acceleration change (DS RPM Delta). (We can actually use up to 30 triggers, which would be 1500 times a second at 3000 DS RPM, and 3000 times a second at 6000 DS RPM !!)

Another thing to note, Traction Control is all, we at Davis Technologies, do. Our units utilize 2 high speed processors to measure and calculate drive shaft data, and nothing else. Our patented systems are not simply a few lines of code thrown into an existing engine management system and called traction control. This is all we do, and all we have done for the past 12 years!

With tools like the simulator, which took nearly 2 years to develop, and the info we gather from helping hundreds of teams, we continue to focus our attention on nothing but traction control, and making our products better. Our motto around here - “The Better It Works On The Track, The More Likely They Are To Tell Their Friends About Us”