By What is a Tuner Module and Why Do You Need One?
In this article, we talk about tuner modules, how they work, what they do, and why every enthusiast needs one. For sake of example, we’ve got the SCT X4 Tuner Module because it’s a great value, and it’s what we’re going to be using to do our how-to guide when we tune our S550 Mustang. Of course, you can buy this and over a million top name-brand products sold by trusted vendors at great prices, and the shipping is always free with no minimum at the Marketplace on Motoroso.com. Let’s get started.
VIDEO: WHAT ARE ECU TUNERS AND WHY DO YOU NEED ONE?
What is a Tuner Module?
Let’s start by talking about what a tuner module is and what it does. A tuner module is an electronic device that connects to the ECU through your OBD2 port on your vehicle, and it helps you to make changes to the ECU. If you’re not familiar with what an ECU is, it’s your Engine Control Unit. It is essentially a computer that controls dozens, sometimes hundreds of variables that affect drivability and performance of the engine itself, like air-fuel ratio and spark advanced control: everything about how the engine works. There is a lot to know here, but there are two things that you absolutely need to know.
First, from the factory, your stock ECU is not pushing the engine to its maximum performance capabilities. That’s because they want maximum reliability and they don’t want to put all that performance in the hands of just any driver, but for us enthusiasts, that means that there’s potential in that engine that has not been unlocked yet. That’s where a tuner module comes in and we think it’s ethically the right thing to do to let it out.
If you already feel this way, and you’ve been doing mods to your engines like air intakes or exhaust, you’re actually affecting the engine in a way that the stock ECU cannot handle and it can’t keep up with it since it doesn’t know what to do with it. You might be running rich or running lean and causing damage to the engine and you don’t want that obviously. You’re also not getting the most bang for your buck out of the mods that you’ve invested in. A tuner module allows you to tune the ECU, adjust for those mods, keep the engine running clean, and maximize the performance gains that you get from all your mods.
So as you use a tuner module to adjust for all the mods that you’ve put on your vehicle, you can tune for things like power and torque output, which is what most people are thinking of using a tuner for, but you can also tune for drivability, reliability, and even fuel economy. There are a lot of different variables that you can configure using a tuner, but we’re going to cover some of the most important and common ones here.
What Can a Tuner Module Do?
AIR:FUEL RATIO
One of the most common terms you’ll hear in the tuning world is AFR, which stands for Air:Fuel Ratio. This is the blend of air and fuel in the cylinder, and you’re looking to strike that perfect balance. Too much air in the engine will run lean, and it’ll get way too hot. Too much fuel, the engine will run rich and waste your expensive fuel and both Rich and Lean have the potential to damage the engine.
IGNITION TIMING / SPARK ADVANCE
Another common variable is ignition timing, which is also known as spark advance. It’s called spark advance because it is the time before a piston reaches the top dead center location in the compression cycle, that the spark is initiated to spark the fuel and drive it into the combustion cycle. This can be used to make more power, but it’s primarily used to control engine knock. Without going into depth there, engine knock is the combustion of fuel when it’s not supposed to happen—separate from pre-ignition which is a different thing. In other words, the combustion of that fuel happening at that moment in time is not good if you want your engine to run clean.
DUTY CYCLE
The next common metric is the duty cycle. This is the amount of fuel being pushed through the injectors into the cylinders. From the factory, your injectors are capable of way more fuel than they’re typically pushing. You can’t just push it to 100%, you generally want to stay around 85%-90% as a maximum, and provided that you’ve got all your other metrics going right, getting more fuel into the engine means more power.
VARIABLE CAM TIMING
The last variable we’ll talk about is variable cam timing. We bring this up because our Coyote 5L has variable cam timing and it is a feature that you’ll find in a lot of other modern high-performance engines. This is a tough one to explain, but a standard traditional cam opens the valves at the same rate throughout the entire RPM range, whereas a variable cam timing system lets you open the valves differently throughout the entire RPM range and tune that to get maximum performance throughout the entire performance cycle of the engine.
As we mentioned at the beginning of the video, our featured product here that we’re showing off is the SCT X4 Tuner Module as an example of a tuner module. We chose it because it’s a really good product at a great value price point: around $400, and you can purchase it Here on Motoroso.com. It’s really easy to use, it’s feature-packed, and it can support two different types of tuning. It has out-of-the-box tunes that are basically plug-and-play performance, but you can also support custom tuning. Let’s go ahead and talk a little bit about these two different types of tuning that you can do with your SCT X4.
Most performance tuner modules are going to come with out-of-the-box tunes that are plug-and-play. The beautiful thing about SCT is that this is a company that is a hundred percent focused on tuning and tuning modules. They have spent thousands of hours developing tunes for most of the most popular applications out there. The tunes that come on there—there’s three of them—vary from mild to wild. This allows you to plug that into the OBD2 port and get more performance from your stock setup right out of the gate and you’re going to fill it in the old butt dyno.
DATA LOGGING
In addition to that, you can add variables like what fuel octane you’re running, your wheel and tire size, and even your OT sensors to make sure that you tweak that stock tune just a little bit better. In addition to that, you can choose the aftermarket mods that you may have already installed from dropdown lists, for things like cold air intakes and exhaust systems and it will adjust those tunes just a little bit with all the data that SCT has developed to get you a lot closer to optimal tune right out of the box. That’s all included plug and play without the need to do any custom mapping, and that’s going to get you to an 8/10 on your tuning.
If you want to go to 10/10 that’s when you get into custom tuning. One of the nice things about the SCT X4 that you can do custom tuning without a dyno by using their data logging feature. Data logging allows you to plug in the X4 to your OBD2 and then log the data as you go out and do some driving. Let’s say you find a road, you do some pulls, you get the car through its gears, and through its RPM range, you can then download the data logs, send them to a remote custom tuner who will evaluate those, and create a custom map based on your actual data. They’ll send that back to you, you download it to the X4, you upload it to your car, and you run it. Then you listen to the button dyno to understand, does the car feel like it’s running better? You can then data log it again and send it back to the tuner.
This method will cost you about $250 to $600 for a remote tuner’s time depending on how many rounds of revision that you do. The only downside to this is that you don’t get the actual power and horsepower numbers that you would get from a dyno.
REAL TIME DATA LOGGING ON A DYNO
While your data logging approach can get you to a 9/10 on that performance scale, the way to get to 10/10 is by using real-time data logging on a dyno. The biggest benefit to this is the real measurement of what the actual power and torque output numbers are on that machine so you know, really, how this tune is actually performing. This realtime data reporting will allow you to have your tuner there, or have your tuner still be running well while you’re actually on the dyno, but allows the tuner to create all the custom variables necessary to maximize the performance or create any of the tuning levels that you want. And if you remember, if your budget allows, you can create up to 10 custom tunes based on exactly what you’re trying to accomplish.
WIFI UPDATES & DTC CODE READING AND CLEARING
There are two last features we want to talk about the SCT X4 Tuner Module that we like. First, it will update by wifi, which is really easy because new updates come out from SCT from all of their efforts every six months so you can always get the latest downloaded into your X4. And second, you can also use your X4 to clear DTC codes and avoid a trip to the dealership.
So we just covered a whole lot of features, and we hope you found that really helpful. You can buy the SCT X4 at Motoroso.com or you can also browse over a million other products. Thanks for reading.
