If you've ever talked to a suspension engineer, shock guy, or read up on suspension setup, you've probably seen where people say the goal is to reduce the contact patch load variation. That is a complex sounding way to say that you want to minimize how much weight moves around on your car to keep the same amount of weight on each tire. We just had a great example of this in practice.

If you look at the photo close, you'll see that there is temperature and shock position for each tire along with lateral G force at the bottom.

If you look close, you can see the variation in the shock position starting around 8600 ft (the numbers on the very bottom X axis). Then, if you look at the tire temps, you see that they have the same variation pattern. As the shock oscillates up and down, the load into the tire varies, creating temp variation. This is shown in the variation of the lateral G force in the very bottom graph. 

The better you can control the suspension movement, the better the tires stay in contact with the road, giving you more grip.

The last neat thing in this data is the big movement in the shock position just before 8500 feet. If you look close, you'll see the front movement happens just before the rear movement. When you measure that offset, it matches the wheel base of the car perfectly. Talk about some great data!

The video explains it all, but the basic idea is to define the corner distance, then take the minimum speed of that defined distance. The video explains it all in more detail and will get you started on another way to measure your performance.

This is just a quick introduction, but it should get you started along with the math channel files from AiM National Training Manager Roger Caddell.

There are many variables that go into selecting the right brake pads. Drivers will talk about initial bite, brake pressure required, modulation, release, and pedal feel. Engineers will look at things like brake pad wear, rotor wear, temperature profiles, coefficients of friction, and many more things. 

Operating temps are very important for the life expectancy of many wheel related items. Wheel bearings, bearing seals, caliper seals, brake lines, tires, brake fluid and many more related items absorb significant amounts of heat from the braking system. All of that heat is a considerable factor in how long those items last along with how long the brake pads will wear before losing friction levels and wearing out.

Using a Texense INFKL 800°C, we were able to monitor rotor temps to compare two different brake pad compounds. We also used a Texense THK 400 along with a specialized thermocouple to monitor the actual brake fluid temperature in the caliper behind the pistons. This gave us some very interesting data in how the brake pads work and some insight into how long they will last and what maintenance issues they may provide.

In both graphs, the solid lines are the maximum temp and the dotted lines are the average. The blue is the same pads in both graphs as the orange is the same in both. Driver, car, ambient temps, and lap times in both runs were very similar and provided a great basis to compare the temps.

You'll note that while the compound in the blue had a significantly lower operating temps, it transferred more heat into the brake fluid. This was due to a difference in pad material remaining, with the compound illustrated in the blue lines having significantly more wear when the tests were conducted.

You can continue analysis like this to include things like max pressure required, average pressure used, max deceleration rate, and many more items. Choosing brake pads just took on a whole new dimension! 

Working with lots of people on their data acquisition systems, I've seen lots of different dash and alarm light configurations. I always try to explain to people that the dash display and alarms are there for them, and they can be arranged in whatever way helps the driver the most. For many people, that means that we put the most important items all on one side, so when a light in an area comes on, they know it's important. Other items that are not as important, go on the other side so they can look and analyze what is going on when they have some time/capacity while driving. 

This is the first time I've seen this. Please don't tape over the alarm lights on your dash! We're here to help. I can walk you through reprogramming your dash so you don't have to tape over lights you don't want to be on!

Proper braking technique braking is probably the easiest thing for most people to improve upon and make a large difference in their driving and lap times. The first area most people work on is  proper application speed and amplitude followed by learning to trail off the brakes and carry more speed into corners. 

One spot to pay attention to is the consistency of how the brake pressure is bled off and how smooth this release of brake pressure is. This first graph shows a good release and a release that could use some work. It's important to work on the skill of keeping consistent and smooth brake pressure throughout the release, especially when blipping the throttle in heal and toe downshifts.

Many times when a driver is working their feet in heal and toe downshifting, their will unknowingly release some brake pressure. This brake pressure variation can cause chassis stability problems, reduced braking efficiency, and an unsettled feeling to the driver. This footwork is a learned skill, so it's something to watch and be aware of in the data. If a driver is having trouble with this, it's a good area to make them aware of and work on improving. Practice while sitting still, at slower speeds, and a strong focus during on track sessions can really make a difference in improving this skill.

One thing that is often overlooked, is that at the higher and higher levels of driving, the differences become smaller and smaller, yet each driver has their own style. Across all of these styles, every driver executes all of the fundamental skills perfectly every time. Even the small things like smooth and consistent brake release are practiced and monitored to make sure that the driver is getting everything from the car that they can.

Lots of people ask how to install different sensors. One of the most common, is the steering sensor. Their are special kits that are sold for steering sensors with belts and pulleys connecting a rotary sensor to the steering shaft, but these have the problem of needing to be tensioned and they often slip in fast steering inputs. A simple method to include a steering sensor is to use a string pot and wrap it around the steering shaft. 

Once you have figured how to mount the sensor, which might require a small bracket, you simply wrap the sensor cable around the steering shaft and attach it. You have to make sure you have the steering wheel turned all the way to one side so that the string is retracted when turned in one direction and then the string is pulled out when turned the other direction. 

The most common size string pot used is a 10" travel, which is fairly long for this application. You want to make sure that you use as much of the travel as possible to get the best resolution in your data. To do this, you can go back to a little bit of you high school geometry class and remember that the circumference of a circle (your steering shaft) is π multiplied by the shaft diameter multiplied by the number of turns from lock to lock. This will give you the travel you need to measure. As long as that is less than around 8" (the 10" travel minus the distance from the sensor to the shaft) you will be all set. If you find the sensor travel will be only a small portion of the sensor travel, you can increase the diameter of the shaft by putting a piece of rubber hose around it as you see in the picture. 

One of the most exciting thing about the new MXL2 and MXG dash data loggers is their ability to provide digital outputs. These digital outputs can be used for very diverse things including extra alarm lights, ECU inputs, fans, pumps, and more. One limitation is that the digital outputs are limited to 1 amp of power draw, so by themselves, they can not operate much more than a light. Trailbrake.net has found a way to work around this - the Cartek Motorsports 4 channel Power Distribution Module (PDM).

Read more after the break.

The Cartek Motorsports 4 Channel PDM is a full motorsport quality, robust device that is fully potted and ready to work in your car, motorcycle, or kart. Each unit is good for a total of 40 amps with singe channel maximums of 10 amps each. The units are very small, measuring just 3.563" x 1.625" x .438" thick. An M6 stud for power input, 1/4" spade connectors for outputs, and a supplied 4 conductor connector and wire for activation. The whole things weighs in at 3 oz and requires no programming or setup. An LED for each channel gives you a status of on, over-current, or short circuit for each channel as well.

Now, you're probably wondering how do you use this PDM to do anything? One example could be to turn on a cooling fan. A simple way would be to make an alarm that when the coolant temp goes over a certain value, like 200 degrees, it would activate an output, that would then turn on a channel in the PDM. This, when connected to a cooling fan, would run the fan until the coolant temp was below 200 degrees. 

If you wanted to do something a little more sophisticated, you could use the hysteresis function and turn the fan on when the temperature hit 200 and not turn off until the temperature was reduced to 190. There are many ways you could do this and for many channels. Maybe you have an auxiliary fan on your transmission or oil cooler? It could run either of those. If you wired the dash digital output to two of the PDM inputs, you could control two items running at up to 10 amps each. This could be a transmission oil pump and the fan on the cooler. 

The four channels available in the PDM mean that you could control two channels with the MXL2/MXG and then use a switch panel to control the other two channels. This simple device, controlling power, protecting from over-currant, and short circuit, opens many opportunities in how to power you car, utilize your dash, and save valuable weight in the car. 

While options here show AiM data systems, they are applicable to all brands of data system that have digital outputs. This includes the Race Technologies DL-1, MoTeC systems, and many others. This system is beneficial for situations without data, as the PDM functions as a relay and circuit breaker all in one small, lightweight package. 

Retail price is $198.30 for the PDM and $95.79 for the 2 push button panel. Send us an email to Matt@TrailBrake.net to purchase or look in our store.

Anyone who is serious about their car, data, or maintenance will know how much time it can take to create a spreadsheet to track the time and/or mileage on parts, get that data out of the logging software, input it into the spreadsheet, all while not making a mistake. At the top levels of motorsport, teams have created their own system to automate this system. For the rest of us, that type of automation has always been out of touch, leaving us to work away on spreadsheets.

Read more after the break

Joris Mans, a Software Developer, decided to create a web application to log time on parts for his car. After working on the website, he realized the potential this has to help other people. With a simple PayPal payment, Dropbox integration, and data files from your MoTeC or AiM system, you will be able to log mileage and/or time on any part you want to enter. A simple layout and user interface make this system accessible to everyone and will save people huge amounts of time.