Chances are you’re already familiar with the ECU on your vehicle and what happens when you tune it using one of SuperATV’s Handheld ECU Tuners. However, the true complexity of what is happening in your ECU before and after a tuner might still be a mystery to you.
Like most, you’re probably just happy knowing that you’ve got more horsepower and a higher top speed. If you want to know more about what ECU tuners do and how we tweak them to get the very best performance, feel free to read on and enlighten yourself. (But we won’t tell you everything. We’ve got to keep some secrets—right?)
We have spent countless hours over the past few years developing our ECU tuners, and we’ve learned a lot through this process. Our ECU tuning team is made up of several researchers from all different backgrounds, each of them bringing diverse and necessary skills to the table.
We have electronic experts, clutch experts, engine experts, and programming experts who have all come together at SuperATV to develop these custom tuners. Keep in mind that, altogether, they have multiple decades of experience—all of which have been funneled into this single project. This is not a simple topic and this explanation will not be comprehensive, but it should prove interesting.
ECU stands for “Electronic Control Unit,” which is a fancy name for a little computer that does everything on your vehicle. Before we even touch it with a tuner, the ECU is already doing a lot of complicated stuff.
When I say it does everything, I really mean everything. It controls the precise timing of your spark plugs’ firing, monitors how much fuel enters the cylinders every time a piston actuates, and interprets the pressure applied on the gas pedal to inject fuel accordingly. When you press the gas pedal down, you’re not giving gas, you’re requesting torque—that’s drive by wire.
It also places artificial limits on your machine’s maximum speed and RPM. It keeps you from driving your vehicle without your seat belt on and will even cut the throttle if you press the brake and accelerator at the same time on some machines.
You are not really driving your vehicle so much as making suggestions to the ECU. It decides what to do from there.
The first step is to figure out which knobs to turn in the ECU. After that, it’s all educated guesses and trial and error.
In order to turn knobs, we have to figure out where these knobs are and what they do. These aren’t actual, physical knobs of course—they’re lines of program code in the ECU.
So first we find the knobs on the ECU by hooking it up to some pretty complicated computer software. At times, this search involves looking through individual lines of code by hand until we see a line that looks like spark plug timing or a rev limiter.
Apart from the lines of code that control limiters, there are three main knobs to look for that control spark, air, and fuel. Finding these can be incredibly difficult and time consuming. We use our in-house chassis dynamometer (dyno) to test the changes we’ve made to an ECU.
“We’re poking around in the dark all day and then we find it!” says the ECU engineer the moment he hears a machine rev above its limit on the dyno. A quick scan of the dyno readout confirms that they’ve got it—the rev limit has been raised from its admirable but cramped ECU-limited RPM to an RPM that will make your hackles stand on end and get your heart thumping. It’s a real “Eureka!” moment every time it happens—a testament to just how complicated the process can be.
Once those knobs are found, some things come easy. Raising the rev limiter or the speed limiter is a no-brainer. Changing the behavior of the gas pedal so that it feels better and more consistent isn’t too difficult, either.
These changes make a huge difference on vehicles like the Polaris Ranger, where you only get a fraction of your performance from the factory. Next, we move on to optimizing for higher octane fuel in order to squeeze out more horsepower and torque, which is a whole other thing.
That’s where the trial and error comes in. Our engineers will tweak spark timing, air intake, and fuel injection. Thanks to their years of experience, they have some idea of what changing a spark-firing angle by a few degrees will do, but they don’t know exactly.
After tweaking, they load their saved program to the stock ECU (this process is called “flashing”), re-install the ECU, and give that vehicle a pull on the dyno.
After analyzing and interpreting the torque and horsepower data provided by the dyno, they take the ECU back out, bring it back to the lab, and turn the knobs some more.
Rinse and repeat repeatedly until peak power or torque is achieved. Then we do it again for high-octane fuel. Then for the next model. Then the next model year. You see? It’s a lot of work. We then save copies of the specific tunes that were made so that we can make more copies and sell them.
But we’re not done yet.
That’s right—when it comes to cutting your vehicle loose, your OEM clutch isn’t the clutch for the job. You can tune and optimize your engine as much as you want and it will look great when you measure the horsepower at the crankshaft. But if you don’t make it work with the clutch on the machine, that power will never reach the ground.
That’s why our job isn’t done until we’ve maximized power for the stock machine and designed the perfect clutch kit to get that power to the ground.
You guessed it—trial and error!
The process of building a new clutch kit involves swapping out primary and secondary clutch springs and adjusting weights on the clutch arms themselves. If you’ve ever bought one of our clutch kits, you’ll know we send them pre-weighted so you don’t have to do any guesswork.
We also send them with a whole bunch of different weights that can be attached to three different positions on the clutch arms, just in case you want to experiment a little yourself. By putting different weights on different points of the arms, our engineers change the torque and horsepower that reaches the ground.
Altogether, there are approximately 36,000 different combinations of weights that can be installed on each clutch arm. Each half gram and each position makes a difference. Combine that with all the different primary and secondary clutch springs that can be installed and you have hundreds of thousands of potential configurations for your clutch.
Luckily, our guys know how to narrow that down to just a few possible candidates. First, they test a stock machine on the dyno so that they know what they’re comparing their changes against. Then they make tweaks and test it again on the dyno.
They make countless adjustments until the best possible version of this graph is achieved. They might remove the clutch, change weights and springs, and rebuild the clutch ten times in one day when they’re in the thick of developing a new kit.
After they’ve got a graph that looks right, they’ll take it out for some field testing. You can tell when they’ve got it right because they come back grinning from ear to ear.
Those graphs are an example of a kit designed specifically to get as much horsepower as possible, but they also use the same process to maximize torque and find a sweet balance between the two.
The clutch kits and ECU tuners are often designed in parallel, with the same engineers working on both aspects. That way we can be sure our tuners and clutch kits work perfectly with each other and deliver pure adrenaline when you floor it.
Trust us, that’s the goal—pure joy. It’s an easy way to measure your success, too. Either you’re blown away that you’ve got this much power in a machine you thought didn’t have any new tricks, or you’re not.
These kits are extremely difficult to make, let alone make them well. Thankfully, we’ve got the process figured out to deliver max HP, max torque, max speed, max durability, and—of course—max fun.
Head on over to SuperATV.com and see just how much fun you can have. We have tuners available for multiple Polaris models, including the General, Ranger 900, and RZR PRO XP. Check out our ECU Tuning page to see how we can take your riding experience to the next level. Don’t see your machine listed? Don’t worry—our team is constantly working hard to deliver new products that you want and need.
Check out our video below showing how easy it is to install a tuner. We’ve got a lot more videos like this one over on our YouTube channel!