The Next Most Important Device in My Race Car !!
by Al Smyth - Portatree Timing Systems, Inc.
When you have already spent thousands of dollars on your race car and you are tapped out, it becomes difficult to justify any additional expense that won't make the race car go fast……. Unless…..
How would you like a device that would tell you whether you have a fuel problem or an electrical problem? How about if it could tell if you were jetted too lean or too rich? Is it clutch or chassis? Was it tire spin or clutch spin? Oil pressure is lowering … is a bearing gone? These are just some of the questions that can quickly and definitively be answered if you had a good data acquisition system in your race car.
When we started building our SS/A 1968 Hemi Barracuda, we knew from the start that we would need to know every piece of information every time the race car went down the race track. The cost of each run is way over $1000 so we just couldn't go for a joy ride and guess what happened. That meant that we would have to choose a data acquisition system for our drag car. Our reasoning was to not just make the car faster, but we needed to learn what was happening with the clutch, suspension, exhaust gas temps, oil pressure, fuel pressure, etc., etc. and how to work with this information to maximize our performance while watching for potential problems.
Most of us are guilty of going over budget on a race car. Lets face it, it is very easy to do ! When you start purchasing items that cost well over 1, 3, even 5 thousand dollars you want to make sure that you protect them if possible. The race car budget can't afford to buy the same item twice. So if you have over $20,000 or $30,000 in your race car, and want to protect those very expensive parts and make your race car perform better, then a data acquisition system is a must have item!!
Which Data Acquisition System should I buy?
The first thing to do is to decide what is the most important information that you would require from your race car. Check out every system that can supply you with this information. You really need to check out a unit that another racer is already using in their race car, watch how they use it, make sure it is user friendly (you don't want to require a degree in rocket science to operate it), make sure that it is durable (you don't want major breakdowns every time you use it), and find out what they paid for it.
My idea was to check out what the circle track and road course racers used. I figured that if they had to collect data for several minutes and more, it would be awesome in a drag car that only raced for 9 seconds !! The system that I selected was a Corsa Instruments Model # 1111. It provided 8 EGT's, G-Force ( X Direction ), Oil Pressure, Fuel Pressure, Engine RPM, Driveshaft RPM, Rear Shock Travel (Left and Right), as well as Battery Voltage and Box Temperature. I selected this unit because I watched the system in use at a Racing Trade Show and the people in the booth impressed me with their racing knowledge.
Putting it in the Race Car
The most important thing to remember when you install a data acquisition system is to use common sense. The second best thing is to read the instructions. The main control box should be centrally located and points in the direction that the Accelerometer (G-Force measurement) requires to accurately measure G-Forces. All control wires should be protected from chafing and heat. They should be wire tied or clamped to keep them from excessively vibrating. Refer to the installation manual for exact placement of all sensors.
Special adapters can be welded into the exhaust headers so that EGT's (Exhaust Gas Temperatures) can be measured on all cylinders with the use of thermocouples. This is a must if you want to detect potential problems in fuel distribution. The temperatures in each cylinder must be equal (within reason) so that each cylinder is providing the same amount of power to the race car. You may also consider an Oxygen Sensor, which will indicate air fuel ratios and help you determine if you have a rich or lean condition. E.G.T's can also help in determining problems. We had a spark plug hit by a piece of debris and close the gap. The data acquisition system pointed directly to the # 4 cylinder due to varying E.G.T and we corrected the problem within minutes.
We elected to have shock travel potentiometers located on the left and right shocks. This helps us determine the amount of load that each shock sees at the start as well as each shift down the race track. The potentiometers look like small air cylinders and must be mounted upside down so that dirt will not enter through the shaft seal as it moves up and down. Linear Potentiometers measure distance and knowing the spring rate ( ex. 125 lbs per inch ) you will be able to determine the shock loading. This will help you determine if one tire is getting loaded more than the other and if a suspension adjustment is in order.
How to use a Data Acquisition System
You must always have a routine in your race car and the data acquisition system should be one of those important routines ! In drag racing, we like to gather data just before staging the vehicle. It is important to turn the data acquisition on at the same point In your routine so that you don't forget and lose the run data. After making the run and returning to the pits, you should download the data as soon as possible for reviewing. You usually have the best recollection of the run when you review the data as soon as possible.
When we get back to the pits with our Super Stocker, we like to review the clutch slip so that we can plan on adjustments. The best part about the data acquisition system is that we can use the information to determine whether clutch or suspension or both need to be adjusted. The data allows you to make adjustments to both clutch and suspension and monitor them both. If you don't have a data acquisition system, then you are confined to making one change at a time to find a solution to your problem(s). You may have a multitude of problems with both, and making one change at a time could take a very long time especially if your shocks have 20 setting adjustments and you rely on seat of the pants to adjust your clutch! Using all of the information on every run will help solve multiple problems quickly and efficiently.
Data Acquisition isn't rocket science, it's just another tool in the battle of competition. Just because you have to use a P.C. should NOT intimidate you, in fact, once you've worked with a P.C. and a Data Acquisition system, you just can't get enough. When you've broken enough parts, had it with seat of the pants evaluation of the run, and are confused by play back tachs, then consider a good data acquisition system for you race car. We did………and it works for us!!!!