Through the ages, gearheads have striven to do one thing and one thing only: go faster.
To do so, sports car racing has always employed the latest technology, even going so far as to grab ideas originally developed to travel the heavens. Yes, the space program has given us more than just Tempur-Pedic foam mattresses and aerodynamic golf balls—it’s also brought the automobile industry aluminum monocoques, advanced composites and, more recently, satellite-based data acquisition systems.
While some of this modern technology might seem far removed from our world, it should be embraced by today’s vintage racers and classic car enthusiasts. Just because we choose to spend our time on cars from another era doesn’t mean that we must use primitive tools. Modern tools and technology can give us all—racers and nonracers alike—faster, safer and more reliable automobiles.
This win-win scenario is easier to achieve than it sounds.
Thanks to the march of progress, today’s enthusiast now has relatively open access to chassis dynos, suspension setup tools and easy-to-use data acquisition programs. Example: In just about every corner of the country, you can tune your car on a chassis dyno for less than a hundred dollars per hour. Today’s vintage racer can also get accurate lapping data for about the cost of a set of tires. Once you get past the initial hurdle, it only takes a little bit of knowledge and a few bucks to bring your effort into the new millennium.
For practical examples of how modern technology can easily be adapted to yesterday’s machinery, we visited the huge SascoSports facility at Virginia International Raceway and shadowed Dave Handy and Jeff Horne as they prepared the shop’s 1970 Lola T200 Formula Ford for the upcoming season. The principles of adapting modern, scientific advancements to classic cars can be demonstrated on any number of subjects, but we chose the Formula Ford racer because it’s so adjustable. Also, thanks to its minimal bodywork, those adjustments can be made easily.
This particular Lola was purchased by Dave more than 20 years ago and has since undergone a full restoration. To say it gleams is an understatement.
As pretty as the Lola is, top vintage racers aren’t just display items: They get raced and improved on a continual basis. For example, the Lola’s 1.6-liter Ford Kent engine was recently freshened by Marcovicci-Wenz Engineering. It now features the latest in national level Formula Ford secrets, yet is still reliable after a couple of seasons.
Dyno Tuning
A dynamometer is simply a device used to measure an engine’s horsepower and torque outputs. These machines have been around in various guises for close to 200 years, but only really became accessible to the masses during the 1990s.
Accessibility improved thanks to the introduction of affordable chassis dynamometers—ones that local speed shops could afford to buy and run. Up until then, only the top race teams had access to dynamometers—and most of those required the engine to be removed from the car for testing. The rank and file instead relied on more primitive tools to diagnose and test their cars, like measured acceleration runs or lap times. Unfortunately, those testing methods weren’t nearly as scientific thanks to all of the possible outside variables.
A chassis dyno not only limits variables, it also takes into account driveline loss, so today we can simply strap a car to a dyno and get some hard numbers in minutes.
Establishing a Baseline
In order to accurately judge the effort, any tuning work has to start with a known quantity. Therefore, we needed to establish a baseline before touching the Lola’s engine. We visited the VIPER Engine and Drivetrain Performance Lab, which is conveniently located on the grounds of Virginia International Raceway, and strapped the car to their dyno.
This lab is a partnership between Virginia Tech, Old Dominion University, VIR and the Institute for Advanced Learning & Research. Their SuperFlow chassis dynamometer’s caretaker, Victor Seaber, is no stranger to racing as he pilots a Formula Mazda in national SCCA Club Racing.
While Dave and Jeff knew that their Lola’s engine was still relatively strong based upon lap times, they had not objectively measured its overall condition or its state of tune. Our dyno numbers would be more than bragging rights fodder, as they would also establish a benchmark for testing and power improvements.
We made three runs on the dyno. The device instantly translated the acceleration rate of its rollers into horsepower and torque readings, and we averaged the peak outputs: 94.6 horsepower, a figure that jibed with other well-built Formula Fords.
Did that tweak really make a difference? The chassis dyno is all-knowing and displays its findings on an easy-to-read chart that plots engine speed against horsepower at the wheels.
The power that an engine develops largely results from combusting the correct mixture of air and fuel at exactly the right time. Get something wrong, and both power and efficiency suffer.
Early methods for testing any engine’s tune were quite simple, as mechanics relied upon three of their five senses. Too rich of a mixture produces black smoke or soot from the tailpipe as well as darkens the spark plug electrodes; a well-tuned nose can also detect too much fuel in the mixture. Finally, a properly tuned engine produces the right harmonics—much like a musical instrument when it’s on key.
Nowadays, the air and fuel mixture is measured using a very sensitive electric device called an oxygen sensor. Most dyno shops have such technology on hand. The sensor itself is mounted in the exhaust stream and sends an electric signal to a small device that does the calculations. The typical air/fuel ratios for a well-prepared, normally aspirated engine range from about 12.5:1 to 13.5:1.
Thanks to the engine builder’s extensive dynamometer testing, the mixture on the Lola was quite good, starting out a little rich in the low and middle range before peaking in the low-13:1 range. This is near optimal for our application; if the numbers didn’t look right, we could have done further tuning.
Timing Is Everything
Now that we knew what we had in our Lola, our challenge was to improve upon it. So, how does one use the dyno to make more horsepower? This machine instantly reports changes; evaluate them as a scientist would and note the effects of a variable in an experiment.
We started our quest for more horsepower by looking at the Lola’s ignition timing. The timing of an engine’s spark is extremely important for maximizing power. Light off the air-fuel mixture too early or too late, and you’ll leave power on the table—or worse, eventually hurt something in the engine. Differences of just a few degrees in ignition timing can make major impacts on power.
In the old days, we set ignition timing by ear. Today, back-to-back dyno runs can yield the perfect setting.
While the spark occurs in a blink of an eye, in reality it takes a measurable amount of time to fully burn all of the air and fuel found inside the combustion chamber. As a result, the ignition must fire an instant before the piston reaches the top of its stroke, which is why ignition timing specifications are almost always noted as the number of degrees before top dead center. Adding to the complexity, ignition timing must increase in relation to engine speed and load.
On a race car like our test mule, ignition timing is typically measured at full advance—after the centrifugal advance of the distributor has already taken effect. Following the engine builder’s advice, the timing on this engine was initially set at 38 degrees BTDC. While the air/fuel curves were dead on, we had some suspicion that we could gain a little more power by fine-tuning the timing.
We added 2 more degrees of ignition timing and made another run. The result was a drop in power throughout the rpm range, as clearly the engine couldn’t use that much advance.
We then backed off the timing 2 degrees from its original setting, down to 36 degrees BTDC. The result was a solid 1.5 horsepower gain and no real areas of loss. Score one for science.
Is it really possible to feel the difference between three different ignition settings? Maybe, maybe not. The dyno clearly shows the winner with glorious color-coded curves.
Stacking the Deck
The dyno can also be used to evaluate hard parts like velocity stacks. Thanks to their bell-shaped aluminum pathways, velocity stacks can theoretically improve an engine’s power by increasing the airflow into the carburetor.
We’ve been hearing big talk about a new dual-throat velocity stack intended for the Formula Ford’s Weber downdraft carburetor. The piece slips into the carburetor and replaces the air cleaner.
Is this velocity stack a silver bullet for more power? Only one way to find out: another back-to-back dyno test. By altering only one variable at a time, we can measure whether a change helps or hurts performance.
We had a hypothesis to test: Besides costing more than $250 and eliminating the protection offered by the air cleaner, would this velocity stack actually improve power? Before and after runs on the chassis dyno would tell us.
The answer: Just a little. We found less than a 1-horsepower improvement across much of the rpm band, meaning we’d probably trade that small boost for the peace of mind that an air cleaner brings. (Of course, there is something to be said for the psychological boost that a new shiny bit brings when you roll up next to your competitors in the grid.)
Eye In the Sky
Like the dynamometer, the stopwatch doesn’t lie. However, the data that the watch relays is just a single dimension of the car’s performance. It won’t reveal exactly how the car is handling or how the driver is performing in the cockpit.
Data acquisition systems go several steps further. They record the car’s speed and cornering forces as well as a host of other parameters—like when the driver lifts off the throttle and gets back on the gas. These systems can even reveal how the car’s aerodynamics and gearing impact lap times.
Onboard data acquisition has evolved from a luxury that only Formula 1 teams could afford to something that even the average club or vintage racer can use. When driving coach Peter Krause of Krause & Associates began using data acquisition products 10 years ago, basic kits from industry pioneers ran at a staggering $12,000. These DOS-based, sensor-laden monstrosities were also unfriendly to use.
“It would take all day to arrange a usable display of just a few performance parameters—that is, even if it worked during the highly instrumented test session,” Peter explains. Today’s systems offer 10 times the computing power at a tenth of the price.
The key to this affordability is the proliferation of global positioning satellites. The same technology that can keep us from getting lost on a trip across the country can also pinpoint our location on a race track. By matching this positioning data along with accurate internal timers and accelerometers, a GPS-based data acquisition system can quickly show a host of information—such as how fast a car is running or how hard it’s braking—on a graphic display of the track.
Installing Data Acquisition
To evaluate our driver’s behind-the-wheel skills at VIR, we installed a Racepak G2X data acquisition system in the SascoSports Lola. Less than a thousand dollars’ worth of hardware would fully monitor both the car and driver.
The installation process was extremely easy. First we strapped the main unit to the chassis and fed it 12-volt power. Then we hooked up the ground and attached the GPS antenna to the outside of the bodywork. A digital display dash was attached within view of the driver.
We then ran a wire into the ignition for a tachometer signal, and added sensors for oil pressure and water temperature. (It was easy to add the sensors because the Racepak system uses standard 1/8-inch pipe fittings.) Then it was simply a matter of turning on the unit and heading to the race track for some laps.
Don’t let the black boxes and laptop computers scare you. Though they were once only found in professional circles, today’s data acquisition systems are quite easy to install and use. The prices have gotten very reasonable, too, with systems starting at less than a thousand dollars.
After the first lap, the unit started displaying lap times as the driver completed each circuit. The rpm, water and oil pressure data were also visible in the display and could be monitored for safety.
When the session was complete, we removed the data card from the control unit and slipped it into our laptop computer for analysis using Racepak’s proprietary software. Once in the system, we could view the track mapping as well as the accelerometer data.
Like the dyno, the data acquisition immediately told us things about the car and driver. For example, Jeff’s best lap was a 2:14.224. However, if we added up his best segment times during that session, we were able to see that he could have theoretically run a 2:12.592—which is close to his 2:12.3 personal record at that track. Now that we had identified where time was being gained and lost, our coach could work on improvements.
The system also told us something about the car itself: According to speed versus acceleration data, the car seemed to lose some steam at the end of the longest straight. This could be due to the car’s horsepower, aerodynamics or gearing, all of which come into play at higher speeds. Thanks to the oil pressure and water temperature data, we also saw that the car’s engine was running within its normal parameters during the session.
Put Me In, Coach
The driver is another factor that can be improved with modern technology, as a driving coach can take the data and show where time can be saved. Even professional race drivers will use coaches to make the most of their efforts. Hiring one is often touted as the best money a team can spend, and can even save cash by avoiding damage to the car.
Driver coaching is typically done during test days or race weekends. Our coach, Peter Krause, will only work with two to five clients during a weekend. His services start at about $500 per day and includes data acquisition training and feedback.
Going faster is definitely a team sport. Jeff Horne, our driver (on the left), greatly benefitted from Tim Anderson’s data acquisition help (center) and Peter Krause’s coaching.
Often Peter finds that the most difficult aspect of training is teaching the kinesthetic sensitivity a racer needs to enter a corner faster than most drivers would like. In other words, he has to make them realize that despite what their senses say, the car will, in fact, still stick at the higher speed.
He’s found that drivers remain at a paralyzing performance plateau, sometimes for years, before they’re able to break through. The application of detailed information collected while driving allows the driver, coach and crew to focus on specific areas that could yield substantial performance improvement.
“I will even jump in a client’s car and do a few clean, tidy, consistent and quick laps, solely with the intent of overlaying comparable speed versus distance traces to identify where the area of greatest need is,” Peter explains. According to him, sometimes just seeing that someone else can do it breaches the plateau.
Analyzing Data
Driving coach Peter Krause likes to chart the speed of the car versus the time it takes to circle the track. In the first graph, the yellow tracing is one of Jeff’s early laps, while the red line represents his fastest lap of the session, the 2:14.2 pass. Even though these laps are only separated by a half second, there are several differences that stand out.
In Turn 1, you can see Jeff adhering to the “slow in, fast out” mantra. The red trace (bottom of the first trough from the left) reaches a lower cornering speed, but he’s able to quickly accelerate and post a faster speed down the following straight.
The same gains can also be seen at Turn 10, VIR’s notorious South Bend. This is the quickest corner on the track and is represented by the fourth trough from the left.
Another reason for the good lap is the speed Jeff carries through Turn 3, also known as NASCAR Bend. (It’s represented by the second trough from the left.) He does the same at Turns 14A and Hog Pen, the last two troughs on the right.
In each case, the red trace that shows the quicker lap has a higher minimum speed than the slower lap. Raising the minimum speeds through the turns raises the lap average.
To pinpoint behavior that is not productive, look at the extra dips that the yellow trace takes in two of the turns. These indicate that Jeff got a little cocky and carried too much speed or applied too much throttle too soon; the secondary dips indicate that Jeff had to back out of the throttle at corner exit. These lifts hurt his exit speed down the following straights.
Racepak’s G2X data acquisition records lap information from internal accelerometers and Global Positioning System satellite signals, and their DataLink software takes all the information and presents it to the driver for review. Here, the X axis is time in seconds, and the Y axis is speed in mph. The yellow line represents one of driver Jeff’s early laps, while the red line shows his fastest lap. Every region where the red line is above the yellow is a segment where Jeff was going faster on track; the bigger the gap, the larger a difference in speed.
Another great way to audit a driver’s performance is to examine why mistakes occur. In the second chart, we again have two charts that show speed versus time. The fast lap is shown by the green line, while the following lap is in blue—and note that the blue line reveals a little slip-up. It clearly shows where Jeff got a little cocky and lost it at the exit of Turn 3. The tracings are nearly identical early on, indicating that he was on another stormer; but of course, when you get greedy, you pay.
While braking for Turn 3—the second downward slope from the left—Jeff released the brakes while traveling approximately 4 mph faster than his previous and best lap, apparently hoping to carry even more speed into and through the corner. As shown by the GPS map on the bottom of the page, Jeff’s errant car left the track in the short straight between Turns 3 and 4. He didn’t spin it, but he still lost 25 mph while making the save before returning to the track. As a result of this off-course excursion, the rest of Jeff’s lap lagged slower than the previous one.
Thanks to today’s data acquisition technology, we can quickly discover the how and why behind Jeff’s incident. Peter’s advice to him? “Take little bites, not big ones.”
In this graph, the green line is the faster lap, and the blue is the slower. They’re nearly identical through the first few corners, but a mistake in Turn 3 results in a huge disparity for the rest of the lap as Jeff is five seconds off his usual pace. The GPS trace below the graph shows the positional data from the car; it’s no coincidence that the path matches up perfectly with a track map of VIR.
Tuning for Turning
Like engine performance and driver ability, a little dose of science can also help to improve a classic’s handling. All suspensions, from those on the earliest wooden carts to the computer-designed masterpieces on Formula 1 cars, adhere to the same basic laws of physics. Rather than guess, today’s garage mechanic can maximize chassis setup with some basic, modern equipment. Remember: Using the right tools can eliminate guesswork and make automotive experiments go more smoothly.
A proper, track-ready alignment can make for huge improvements in lap times and drivability. Although we have all seen the ads in the paper touting four-wheel alignments for $79, correctly aligning the wheels on a performance car is not something that most local tire shops can do. Luckily, you can do it yourself.
Modern tools can greatly benefit our older classics. A pyrometer quickly shows how hard each portion of a tire’s tread is working. This data can then be used to zero in on ideal tire pressures and alignment settings.
Alignment settings—especially the camber of the front wheels—are best tested and adjusted using a tire pyrometer, which is a highly accurate probe-type thermometer. The probe is simply stuck into the tire’s tread after a track session, and typically three readings per tire are taken: inside, middle and outside. The temperature data simply and quickly reveals how hard each part of the tire’s tread is working. Basic pyrometer models start at around a hundred dollars.
The goal of suspension tuning is to achieve uniform readings over the tread of the tire. However, like most folks in the field, Rob Doddman of Abacus Racing follows the well-adopted theory that it’s best for the inside portion of the tread to be a little warmer than the outside. “About 20 degrees warmer on the inside really helps,” he notes. A quality camber gauge also helps generate repeatable numbers; these tools also start at around a hundred dollars.
Our test sessions at VIR indicated that the SascoSports Lola was quite happy with its current camber settings. The car entered the session with 1/2 degree negative front camber and 1/4 degree negative rear camber. Negative camber helps counter the effects of body roll, and in this case not much is needed since a Formula Ford tends to remain flat through the turns.
As a practical example of how camber can affect lap times on something a little more upright, we’ve seen close to a two-second improvement from just camber adjustments. On a new MINI Cooper, we dropped our lap times at the Streets of Willow track from 64.49 seconds to 62.78 once we increased the negative camber from 1.0 degrees to 3.0. In addition to the better lap times, our tire temperatures showed that the entire tread was working equally hard.
Corner-weighting scales show how a car’s weight is distributed over the four tires.
We have a tip for those looking to maximize their production-based cars at the track: Get as much positive caster possible. Caster is the angle of the steering pivot relative to the ground. It improves high speed stabilty, and increasing caster also increases the effective negative camber of the front wheels as steering angle increases. For example, on our Triumph TR3 race car, we canted the upper ball joints backward to get more than 7 degrees of caster, about 3 degrees more than stock.
We plan to vary the caster from side to side as needed. For example, if a track has more right-hand turns, we’ll add more caster to the right-front corner of the car.
Weighting Patiently
Like many experts, Dave and Jeff say that no suspension tuning is complete without putting the car on corner-weighting scales. These scales, as their name implies, accurately measure the weight resting on each of the car’s four tires.
Corner-weighting scales have also been helped along by technology, as they’re now computerized—as well as more accurate and less expensive than their forerunners. Today’s complete systems start at around a thousand dollars, and that includes the four scales as well as the control unit and all required cables.
Adjusting the weight at each corner of the car will allow the suspension to work predictably and consistently. Threaded shock collars or shims can be used to change the car’s weight distribution until an ideal balance is achieved.
While it’s hard enough to get a 50/50 front-to-rear balance on many production-based cars, there’s still more work to be done. An important piece of data is known as the cross-weight percentage, which is the sum of the right-front and left-rear weights divided by the total weight. Oval track racers call this wedge, and this information can help decipher handling ills.
A car with too much wedge—meaning its cross-weight percentage is above 50 percent—will probably understeer in left turns. A car with a cross-weight percentage of less than 50 percent will understeer in right turns. What does this mean? If the cross-weight isn’t close to 50 percent, there’s a good chance the car will exhibit different behaviors from corner to corner.
A car should be corner-weighted in as-raced condition, meaning with the proper fuel load on board and the weight of the pilot in the driver’s seat—Jeff notes that bags of sand work well here because they are reflective of a person’s mass. Tire pressures are set before the car is rolled onto the scale, as deviations can affect the distribution of weight.
To correct this situation, Jeff raised the right-front corner and lowered the left-front a touch to equalize the cross-weights. Raising a corner (either by turning an adjustable spring collar or adding spring shims) will increase the weight carried by that tire. It will also reduce the the amount of weight riding on its opposite tire by a corresponding amount. In theory, this simple adjustment will help the car in left turns.There was much head scratching after we weighed the Lola, because the car’s corner-weights had shifted since its last weigh-in. Then we realized the culprit: Our data acquisition system was predominantly mounted on the left side of the chassis. On a car as light as a Formula Ford, a change of even a few pounds can be seen on the scales and felt on track.
“We had to screw the spring perches into all kinds of unnatural positions,” he explains. “We were worried that we had a badly bent frame or even something broken that was missed on assembly.” Corner-weighting a car can also reveal hardware problems. Dave explains that when they first reassembled the Lola after its restoration, they couldn’t get the weights anywhere close to reasonable.
After checking everything visually and finding nothing, the team pulled the shock absorbers and springs. They found a mismatched set of springs on the rear. The difference was only 50 lbs./in., but once matching springs were installed the corner weights came right into line.
“If we didn’t have the ability to put the car on the scales, we might have never realized this inconsistency and would have forever wondered why it was locking a single front brake and feeling grossly different from right to left turns,” he explains.
Our Scientific Conclusion
The proper application of both modern technology and basic scientific method can improve your classic, whether it’s used on the road or track and without going against the spirit of the hobby. Why use outdated technology and concepts when there are so many better options out there? You don’t need to rely on conventional wisdom when you can tune and test for yourself.
We enthusiasts can finally operate like the engineers, builders, drivers and crews do at the highest level of motorsports, finding out what really works instead of relying on conjecture, assumption and urban legend. The fact that all of this technology is not only more readily available, but also at a much more reasonable cost, makes it that much more important to use. If you don’t, your competitor will.
Dave and Jeff, our test subjects, will be hitting the track hard in 2009. They now know that their Lola is up to snuff, and they have the charts and graphs to prove it. Look for them and the Formula Ford at a race track near you—but don’t expect to see much aside from their tailpipe and the occasional flicker of brake lights.
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By Per Schroeder
