18 Dyno Time Tips That Make Each Dollar Count

1. Check the Obvious

Before you go to the dyno, perform a few obvious checks: Make sure the engine is in good shape; especially establish that there is even compression among the cylinders. Make sure there’s fresh fuel in the car and that the battery is strong enough to handle 20 to 30 starts in an hour. And finally, ensure that your accelerator pedal opens the throttle all the way.

2. Baseline First

Photography Credit: Tom Heath

Before you start modifying your car, get a baseline of its performance. Those first pulls will reveal some good information, plus you’ll now have a benchmark for future changes—are those later mods helping or hurting?

The baseline run is the best time to make sure the tune-up is good. You won’t make any power with a baseline pull, but you may be able to retrieve lost power when you find out your tune-up is bad.

3. Try Not to Tune on the Dyno

Photography Credit: Tom Heath

While the dyno is a great place to do fine-tuning, it’s about the most expensive place to perform a basic tune. Before you go to the dyno, make sure that the ignition system is in good shape and properly set. Likewise, is the fuel/air mixture at least close to dialed in? We always make sure the car is running great before going to the dyno—it’s the fine-tuning that gets us those last few horsepower.

4. Pick a Good Shop

Photography Credit: Per Schroeder

Dyno shops are getting more common, and it’s likely you can find one within an hour or two of your home base. If you’re lucky, you’ll have more than one available. 

We look for well-organized shops that consider safety rule number one. We also prefer shops that know our car or are at least familiar with  its parts. In other words, a crew that’s more comfortable with carburetors and points may not be the hot ticket for a twin-turbo Supra.

Once we find a shop that we like, we try to do all our work there. Why? Different dynos can produce slightly different data, even if two shops have the same equipment. If we want apples-to-apples comparisons, we don’t throw in an orange from a different shop.

5. Make a Plan

Never go to the dyno without a plan. If you’re just baselining, it’s easy: Make two or three pulls that repeat and you’re done. But if you’re testing parts or tuning, plot it all out in advance. 

Don’t plan on making more than one change at a time, as you won’t know which change made a difference. Also, make sure you’ve got the tools and parts to make that change. Share your plan with the dyno operator so he knows what to expect—maybe he can provide some tips along the way.

6. Order Matters

As you make your plan, remember that the order of tests matters. Start by tweaking your tune-up—ignition first, then air/fuel. Then start changing parts. Once you start swapping components, you may have to play with air/fuel again. Ignition, however, shouldn’t need any changes.

7. Rehearse

Now that you have a plan, rehearse it before you go to the dyno. Make sure that all the parts fit. Also ensure that the car runs once those new parts are installed. 

You’ll also need the right tools for the job. Make sure you can properly tune once the new parts are in place. Completing all of these steps before heading to the dyno will save you a lot of time and money compared to fumbling around when you’re on the rollers. Remember, once the car is on the dyno, the meter is ticking.

8. Bring Tools

First of all, it’s pretty flaky to borrow tools from the dyno shop. Second, you’re going to work more quickly with your own tools, which means money saved.

Our rehearsals show which tools we need to bring, and we lay out everything before we put the car on the rollers. We put the parts right next to the tools, too, ensuring that we can quickly and efficiently tackle each installation and adjustment.

9. Don’t Stay Too Long

Photography Credit: J.G. Pasterjak

We rarely stay on the dyno for more than an hour. We usually make just a small number of tweaks per session—maybe three to five. We have found that attempting too many changes during one visit leads to sloppiness, fatigue and confusion. 

We’d rather have three one-hour dyno sessions than one three-hour session. It may mean more trips to the shop, but we always get better results with shorter sessions. Plus, sometimes the data from the first session will change our plan for subsequent sessions and increase power, lower costs, or both.

10. Stuff Happens

If things go bad, go home. If you’re not making any power or are generally just stinking things up, it’s expensive and frustrating to stay on the dyno and try to make amends. Get the car off the dyno, lick your wounds, and go home to figure things out. When you’ve got the situation fixed, you can return with a clear head and make some good pulls.

11. Repeat Early and Often

Photography Credit: J.G. Pasterjak

If you get great numbers on a pull, after doing  a happy dance perform a follow-up pull. Sometimes funny things happen on the dyno that make numbers look better—or worse—than they really are. Make sure the numbers repeat at least once (we prefer twice) before you trust them. And if they don’t repeat, it’s likely that something’s going wrong with your car or tune-up.

12. Keep Great Notes

The dyno operator can usually record some information about each pull, but we like to keep our own notes. We just jot down everything in a notebook. 

We usually can write our notes faster than the operator can type, and since we have unlimited room we can record more information about each pull. We then keep all of our notes in a binder so we can look back on previous pulls as we’re making future plans.

13. Get a Copy of the Dyno Software and Data

Photography Credit: J.G. Pasterjak

You aren’t limited to looking at the data at the dyno shop. Some manufacturers, DynoJet in particular, let their customers download a copy of the dyno software; likewise, some operators can download the data to a disc or card. The end result: You can manipulate, graph and print the data at will. This step gives you the tools to try hypothetical modifications and digest all of the data. 

14. Get as Much Data as You Can

Photography Credit: Tom Heath

Power and torque are great, but it’s best to gather more information. Of course you’ll want rpm, but make sure to record weather conditions as well any other pertinent data. 

We always get wide-band oxygen sensor readings and anything else available: fuel you have, oil temp and so on. The more data present, the better you’ll understand your car.

15. Read the Line

Never mind peak numbers, the power curve itself can say a lot. In this case, dips in the torque and horsepower curves meant that something was wrong—very wrong. The air-fuel data revealed a lean spot that corresponded with the dips. Correcting the jetting removed the dip and greatly improved the car’s acceleration.

Aside from the numbers, the horsepower and torque curves themselves can reveal a lot of information. Both lines should be consistent and smooth, while dips or flat spots usually mean there’s a problem. These issues are usually tuning-related—something is either too rich or too lean. 

Bumpy lines can signal a driveline vibration—maybe a tire is out of balance. The bottom line is that reading the lines will help you dial in your car.

16. Keep All Your Data Forever

Photography Credit: Carl Heideman

The more data you have, the smarter you’ll get. Even data from a previous car can help. 

After a while, you’ll find that you can use all of this data to extrapolate results and hopefully speed your planning and actual dyno time. For example, if you consistently find that a certain brand of air filter produces good results, you can probably bank on that knowledge when planning future modifications.

17. Study Early and Often

Why did we start this story by lobbying for dyno time over hard parts? Because you’ll learn a lot by compulsively studying the dyno data. 

When you get home, spend some quality time with the dyno curves. Reread your notes. Find out what’s really going on. If it starts to hurt your head, that’s good: You’re learning from the data. 

You also don’t have to study just your own data. Thanks to our friend the Internet, you can often get figures from other people with similar cars or setups—maybe their dyno data will give you enough information to make your next trip to the dyno much quicker and more productive.

18. Follow the Dyno’s Driving Advice

Now that we have hard dyno evidence of power gains, it’s time to hit the track with confidence. Photography Credit: Chris Clark

Hopefully every dyno session reveals more power, but even if it doesn’t you can increase on-track performance by applying the data to your driving style. Once you know your horsepower and torque peaks, you can pick your shift points—and that will earn you some speed.

Maybe the dyno revealed a flat spot or drop-off. If you can’t change the curve, at least you can drive around it. The point is, not only does the dyno reveal how much power is being made where, but it provides information regarding the available powerband. And that’s money in the bank.

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