Dynamometers: they’re known as the doctors of performance testing. When you attend a dyno tuning session, “You can see the power increase (or not) as the changes are made,” says John Potucek, Product Master Data Speed and Performance Team Leader and grudge racer. “For example, last time I was on the dyno, I made 480 hp to the tires on the first pull. An hour later I was at 740.”
While dyno testing gives vehicle owners a taste of the numbers that a ride can put up, Potucek says, “Unless your car can show its potential at the track by proving those numbers, then it’s nothing more than just a piece of paper.” Still, it’s worth having a baseline. Potucek helps us break down what you should be prepared for at your upcoming dyno tuning session.
Know Your Dynos
Potucek explains that there are two main types of dyno testing—engine or chassis. “An engine dyno is just that, for the engine only. This is typically used by engine shops after they just built an engine and before it gets installed or bought by a customer. These numbers are ‘flywheel horsepower’. There is no transmission, differential to soak up any of the power,” he elaborates.
Though the engine dyno is very useful, most dream of going to a shop equipped with a chassis dyno to test full power at the wheels. “This number is oftentimes a shock to people because it’s lower than they were expecting. I’ve been there! A chassis dyno is very valuable to tune for max performance, but it’s always good to follow up street tuning to get the drivability 100%,” says Potucek.
To run a chassis dyno, the whole car will be put to the ultimate test. Seeing as the whole package is mounted up for power pulls, you’ll want to make sure your ride is dressed for the occasion.
Choosing the Right Shop
So, you want to schedule a dyno tuning session. What exactly does that entail? Potucek advises that in most areas there aren’t many to choose from, so you should be prepared to do a little research—and driving. “I drive two hours each way for the dyno I use,” he says.
As far as picking the right one, “Word of mouth is a big thing. Good shops get a good reputation fast. On the same note, shops with a bad reputation are usually easy to spot. Ask around on the online forums or car groups on Facebook. You’ll get answers pretty quickly,” he points out.
Additionally, like most services performed by professionals, you should expect some significant out-of-pocket expenses. Potucek explains, “If you’re paying for a dyno tune (where the dyno operator is also tuning your car) $300 -$500 is a good base. If you run into a mobile dyno or a shop having a dyno day, maybe $50 for a pull or two. But there is no tuning in this option. They only strap your car down and floor it.”
Preparing for a Dyno Tuning Session
Preparing your car for a dyno appointment is crucial to having a productive and satisfying visit to the shop. Most of the work is done to make sure your car is in tip top shape. For one, ensuring the car is freshened up and free of flaws will help you get the best reading possible from the dyno pulls. Second, you are going into a shop owner’s prized room. Rolling in with leaks or mechanical issues not only affects your results, but it leaves a mess! Be mindful that someone will have to clean that up after you leave. Remember, many of these shops charge a per hour rate—so you may even get charged for time spent wiping up your spills.
The best thing you can do to prepare for your dyno tuning session is to build a checklist. And first up—give that ride a good tune. Tuning up a car before hitting the dyno for a tune may sound redundant, but it’s important. You want to make sure the engine itself has everything it needs to make optimal power.
Start with your plugs. Make sure they’re the right ones and that they’re fresh and properly gapped. You will also want to check that fuel filters, air filters, and oil filters are in good shape. You’ll be pushing your car to the limit—don’t starve it of valuable resources. Also, make sure all moving parts are in proper working condition and are good and clean.
Belts and Hoses
While you’re prepping the engine, take a look at the belts and hoses. In fact, you’re probably better off replacing them with brand new pieces. The fact is, a dyno tuning session is hard on the engine and any weak points will be exposed—in the worst possible way. By making sure the belts and hoses are in good shape, you are at less of a risk of popping or busting them.
Fresh oil in the engine, transmission, and the differential can all impact the dyno reading. Additionally, fresh fluids are much safer for the operating system as it is put to the test. Make sure any leaky plugs and gaskets are fixed before you head out. Also, it’s wise to check that the gas in the tank is abundant and fresh. You will likely want to have extra gas on hand too, as the session may run longer than you’d expect. Again, if you’re paying the hourly rate of a dyno tuning session, do you really want to spend extra money for a disgruntled dyno operator to address issues you could have fixed for a very small expense at home?
The tires are in direct contact with the rollers that give you the reading. So ideally, you should run performance tires with wide contact for better traction. However, this isn’t the real issue. Dyno operators can address tires that lose traction. What they can’t adjust for are neglected tires sporting poor quality rubber. Popping a tire on a dyno run can be just as deadly as popping one at speed on the highway, and should be taken very seriously. Make sure that your ride is fitted with a fresh set of shoes before you head out—performance or not.
The last item on your dyno tuning session checklist should be preparing to make changes to the car on site. “Give the car a ‘once over,’ especially on a new build,” advises Potucek. “If you can, drive the car for a few heat cycles before getting to the dyno. That way, you can see if any problems pop up. I like to bring a spare belt, spark plugs, ignition coil, and my small tool box. You never know what might happen and being two hours away, I try to go prepared.”
Additionally, if you want to test out a few different features or settings for your ride, make sure you have what you need to do so. Don’t expect the techs to do research on your car or handle the mods for you. These shops are super busy and no one likes a dyno hog. If you want to run a few different variables, have the resources on hand and be prepared to make the changes.
Have the Right Attitude
Prepping for a dyno tuning session can be a little stressful, which is why having a checklist will keep you on track. Because, truthfully, it’s completely worth the time and investment. These sessions ensure your car is running at the top of its game. Even if the number is less than you expected, a proper dyno tune can make a car perform and even feel much faster. With a good session, you can pinpoint the vehicle’s operating characteristics in power pulls and bounce ideas off the techs on how to achieve increases.
Going in prepared will help you look like a considerate professional—the type of customer that technicians love to help. Remember, you get what you give, and you’re going to have to “mentally prepare yourself for someone else to floor your baby as you watch!” jokes Potucek.