Tech: 2015 Mustang Tuning

2015 VMP Mustang Featured

From the Start

Jumping on VMP Tuning’s 2015 Mustang project at the beginning with tuning, fuel, and a CAI

By Steve Turner
Photos courtesy of VMP Tuning

After waiting patiently for the 2015 Mustang that his company ordered many months ago, Justin Starkey eventually decided he needed his VMP Tuning development car right away. Shortly after we crossed paths with the Starkey family at the Brothers Performance car show, they loaded up and headed to Georgia to take possession of a GT equipped with an automatic transmission.

It should be no surprise that VMP Tuning’s Justin Starkey headed straight to the dyno with the company’s new 2015 Mustang GT project.
It should be no surprise that VMP Tuning’s Justin Starkey headed straight to the dyno with the company’s new 2015 Mustang GT project.

He was ready to hit the dyno and start tweaking the calibration with his SCT Performance software, but Justin learned that the dealer had filled the VMP GT up with 87-octane fuel. Rather than being upset, he used it as an opportunity to see how the latest Mustang responds to various fuels. After burning off most of the 87 on the street, he hit the dyno to baseline the car. From there he climbed the ladder with fuel and tuning.

Before modding the car at all, Justin wanted to investigate the affects of switching fuels. He climbed the ladder from 87 octane to 93 octane to E85 with interesting results.
Before modding the car at all, Justin wanted to investigate the affects of switching fuels. He climbed the ladder from 87 octane to 93 octane to E85 with interesting results.

However, along the way, he learned the car didn’t enjoy the dyno at first.

“On the dyno, you will get all kinds of flashing errors on the dash, hood ajar, abs, etc. At one point it would not let me turn traction control off,” Justin explained. “Eventually, the PCM will detect the front wheels are not spinning at all and the rear wheels are turning easily, it will default everything to off, you will get the ‘Check Brake System’ warning and that’s when you are good to make a clean WOT pull.”

After tuning up the VMP GT with various fuels, Justin stepped up to JLT Performance’s cold-air intake.
After tuning up the VMP GT with various fuels, Justin stepped up to JLT Performance’s cold-air intake.

With the all clear from the PCM, Justin stepped up to 93-octane pump gas with no tuning to see how the factory PCM would react to tuning via SCT Performance software and hardware. Then he dialed-up a more aggressive cal for the 93 octane and saw some solid gains. After draining the 93 and adding E85, he saw increases again. Then he dialed up the cal for the corn and really saw improvements. The cherry on the sundae was a move to a JLT Performance CAI.

Since the VMP GT was filled up with 87-octane fuel when Justin picked it up, he decided to baseline it on the low-octane pump gas. Just switching to the good stuff added 7.82 horsepower and 9.78 lb-ft of torque.
Since the VMP GT was filled up with 87-octane fuel when Justin picked it up, he decided to baseline it on the low-octane pump gas. Just switching to the good stuff added 7.82 horsepower and 9.78 lb-ft of torque.

With the first round of tuning and mods complete, it was time for Justin and his wife Rebecca, an accomplished drag racer, to head for Orlando Speed World to see how the 2015 Mustang would run with E85, tuning, and a CAI on the stock 235/50-18s tires.

“Launching soft, the car spun through First but hooked once in Second. After that, we let the car sit for about 20 minutes and lowered the tire pressure. We took turns driving, we continued to practice launching, lowered the tire pressure to 32 psi, and did bigger burnouts,” Justin explained. “On the last pass it all came together and the car pulled a 12.3 at 115 mph with a 1.89 60-foot. Some tuning tweaks to the transmission throughout the night helped the car run slightly quicker.”

They followed up the stock-tire passes with some runs on Race Star drag wheels and drag radials. With better traction, the tuned up auto clicked off a 12.11 at 116 mph, so with just a CAI, E85, tuning, and traction this automatic GT is teetering the precipice of 11s, and we can’t wait to see where it goes from here.

Wherever it’s headed, there’s a pretty good chance it will pick up a VMP TVS supercharger along the way, and even better chance you can read more about it right here.

Justin used a good trick of disconnecting the feed line and using tuning software to command the fuel pump to run. With the 87 gone and 93 in the tank he could use his tuning expertise to dial in the stock engine with a more aggressive calibration. That added 7.09 hp and 6.11 lb-ft. Simply swapping to E85 with this calibration shifted the numbers up by 13.1 hp and 11.53 lb-ft.
Justin used a good trick of disconnecting the feed line and using tuning software to command the fuel pump to run. With the 87 gone and 93 in the tank he could use his tuning expertise to dial in the stock engine with a more aggressive calibration. That added 7.09 hp and 6.11 lb-ft. Simply swapping to E85 with this calibration shifted the numbers up by 13.1 hp and 11.53 lb-ft.
Turning up the wick on the calibration with E85 added 15.72 hp but gave up 2.29 lb-ft of torque.
Turning up the wick on the calibration with E85 added 15.72 hp but gave up 2.29 lb-ft of torque.
Finally, before heading to the racetrack, Justin added one of JLT Performance’s cold-air intakes, which added peak-to-peak gains of 10.02 horsepower and 11.83 lb-ft of torque, but as you can see in the chart, the gains were even greater at the top of the tach.
Finally, before heading to the racetrack, Justin added one of JLT Performance’s cold-air intakes, which added peak-to-peak gains of 10.02 horsepower and 11.83 lb-ft of torque, but as you can see in the chart, the gains were even greater at the top of the tach.
Whenever we can get access to the raw numbers we like to take a look at them to examine the trends. While the graphs have a much higher resolution of data points, this sampling can more clearly show how the changes impacted the vehicle’s performance.
Whenever we can get access to the raw numbers we like to take a look at them to examine the trends. While the graphs have a much higher resolution of data points, this sampling can more clearly show how the changes impacted the vehicle’s performance.

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