Steve Turner
Former Editor, 5.0 Mustang & Super Fords
May 7, 2014

Horse Sense: If a handheld tuner isn't your style, SCT also offers a solution to tune with the Android or iOS devices, the iTSX (PN 4015). If you'd rather have a dedicated color screen, the Livewire TS (PN 5015) is your move. No matter what device you choose, they all allow you to flash your Ford's PCM with a performance calibration from SCT or a custom calibration created by the tuner of your choice.

There was a time when Mustang fans believed that electronic fuel injection marked the end for performance modifications. Today we can't even consider hopping up our 'Stangs without recalibrating the powertrain control module that runs the EFI. Tuning is a necessity, but one that has enabled the kind of driveable performance that we could only dream of when carburetors ruled the world.

A mainstay in the world of modern tuning is SCT Performance. At many of the shops we frequent, SCT's X3 Power Flash handheld tuner is the device that rewrites the PCM calibrations to allow the incredible performance we document here on a regular basis. In the world of technology, however, it is essential to update products, even highly successful ones, to stay competitive. That's just what SCT has done with its new handheld tuner, which will replace the popular X3.

SCT Performance’s Matt Alderman was kind enough to demonstrate the new X4 for us on his modified ’14 Mustang GT. He assures us that he’s not trying to imitate a Shelby by adding the grille. He says grafting the GT500 grille to his GT resulted in lower inlet and coolant temps thanks to the improved airflow.

"Our primary missions when developing the X4 was make it smaller, more compact, and add a color screen. That is what our customers told us they wanted, and we always listen to them," explained Tim Roi, marketing manager at SCT Performance. "Of course we added some other cool features like a detachable cable and built-in Wi-Fi…"

With our lives filled with constantly evolving technology, it only seems right that our tuning hardware get more modern as well. Two years in the making, the latest piece of calibration equipment in the SCT arsenal is the X4 Power Flash handheld tuner for '96-and-up Fords (PN 7015). It's a sleeker, smaller tuner that sports those aforementioned modern accoutrements like a sharp color screen and Wi-Fi connectivity, in addition to all the tuning capabilities we've grown accustomed to.

"Obviously technology has changed since we introduced the X3/SF3 products. Electronic components have gotten smaller, and we are taking full advantage of that.

"Smaller components have allowed us to make the X4 smaller, while still giving it a boost in power and memory. We don't really need the extra power and memory now, but we might down the road, especially with the size of the newer vehicles' PCM code getting larger and more complex."

Another addition to the X4 are dual analog inputs to extend its datalogging far beyond the digital data flowing out of the OBD-II port.

SCT Performance’s new X4 Power Flash is a sleeker, more modern handheld tuner that delivers the performance tuning you expect, and a few new features that are sure to become essential aspects of your tuning repertoire.

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"Our customers love having the ability to datalog their vehicles, said Tim. "The ability to datalog most of the vehicle's OBDII parameters is built right into all of our devices, but often our customers want to datalog other external devices using their SCT product. The analog inputs allow for that."

Tim elaborated: "For example, if you have an older Mustang that doesn't come from the factory with a wideband air/fuel sensor, you can still datalog air/fuel using your SCT device by hooking a wideband to the analog inputs. In fact, we even have the most popular math formulas already setup in the device so all the customer needs to do is wire it and select their device. Basically, any device that outputs a 0-5 volt signal can be datalogged using the analog inputs."

Of course, the headlining new feature of the X4 is its Internet connectivity via Wi-Fi. This feature is exciting not only for easing updates, but it opens the door to myriad possibilities down the road.

"… If you have ever updated an existing SCT device, it can be a tedious experience. Downloading software, hooking it to your computer, getting Windows to recognize it, all are challenging to put it mildly." Tim said. "Adding Wi-Fi to our X4 allows you to simply connect it to your wireless network or hotspot, select ‘Device Update' in the device menu and it does the rest. No computer or special software required."

We use electronic tuning regularly in our work here, so we were anxious to get a peek at the X4 in person. Fortunately, SCT invited us over to see it in action before it officially hit the market in early March of 2014. In our experience, this device is attractive, user-friendly, and it worked like a champ for our demonstration. We have a feeling we'll be using it regularly from now on.

You can buy one for around $400 from an SCT dealer, but before you do, keep reading to see what it's like.

On the Dyno

Before joining SCT as a calibrator, Matt Alderman founded the performance shop 'Street 'Stangs (, where he tuned up his GT. His shop uses a Mustang Dyno, which is where these baseline numbers originate. The Bolt-Ons & Tune numbers were recorded on SCT's in-house Dynojet chassis dyno. Obviously these numbers aren't directly comparable. We aren't trying for science, but since we were running his car and its interesting combo, we thought it worth the time to give you a ballpark idea of how far the car came with the addition of bolt-on mods and tuning.

Matt opted to maximize his GT's naturally aspirated performance, and having driven in the car, we have to say he made the right choice. The car ripples with bottom-end torque and sparkles as the tach searches for the limiting peg. The car's most aggressive mod is a quartet of Comp Cams' ( Stage 3 bumpsticks (PN 191160), designed for ample gains from 5,500 to 7,100 rpm. The induction side is based on Ford Racing Performance Parts' ( Cobra Jet intake (PN M-9424-M50CJ) and FRPP Super Cobra Jet oval throttle body (M-9926-SCJ). He was an early adopter on the CJ intake, so Matt grafted on a JLT Performance ( CAI for a Three-Valve 4.6. He thinks his combo might benefit from a larger induction tube, but this combo seems to work just fine. Rounding out the package is a pair of Stainless Works long-tube headers (PN SPM11HDR) backed by a Solo Performance ( Mach-X after-cat exhaust system (PN 993149). All told, it cranks out 455 horsepower at the feet and drives like a dream. Well done, Matt. Well done.

Suffice it to say that modern Coyotes are impressive beasts, especially when tuned using an SCT X4. Clocking in mid-400-hp numbers with ample torque from a high-winding, naturally aspirated engine, thanks to some carefully selected bolt-ons, is stout. Add in that the car drives like stock thanks to Matt's tuning acumen, and you can see why these engines have created such a stir.

Kind enough to demonstrate the X4 on his own ’14 GT, Matt Alderman’s ride puts down 455 horsepower and 388 lb-ft at the feet thanks to a Cobra Jet intake manifold, a Ford Racing monoblade throttle body, a JLT CAI for a Three-Valve 4.6, Comp Stage 3 cams, and Stainless Works long-tube headers. Matt was early on the CJ intake conversion, hence the Three-Valve induction. He hopes to unlock more horsepower with a CJ-specific CAI.
Not only did we use Matt’s GT for a dyno demonstrator, but he was kind enough to let us take it for a spin. The car’s flat torque curve and stock-style driveability are a testament to his tuning skill. You’d expect a short-runner intake on a high-winding engine would be soft down low, but not so on Matt’s 5.0.
With this optional, $29 mount, you can adhere your X4 to the windshield, which is particularly useful if you need to watch the gauge mode. You can adjust the orientation of the screen from landscape to portrait depending on how you’d like to mount the X4.

Baseline* Bolt-Ons & Tune** Difference
RPM Power Torque RPM Power Torque Power Torque
2,508 116.00 245.00 2,500 140.18 294.48 24.18 49.48
3,008 152.00 267.00 3,000 186.26 326.08 34.26 59.08
3,508 191.00 288.00 3,500 236.75 355.27 45.75 67.27
4,008 227.00 300.00 4,000 270.06 354.59 43.06 54.59
4,508 270.00 317.00 4,500 315.84 368.64 45.84 51.64
5,008 293.00 309.00 5,000 358.08 376.13 65.08 67.13
5,508 320.00 306.00 5,500 396.28 378.42 76.28 72.42
n/a n/a n/a 6,000 412.14 360.78 n/a n/a
n/a n/a n/a 6,500 437.09 353.18 n/a n/a
n/a n/a n/a 7,000 442.70 332.18 n/a n/a
n/a n/a n/a 7,400 427.46 303.70 n/a n/a

*Mustang Dyno **Dynojet