Modern performance vehicles truly are marvels of engineering. An immense effort is put forth designing these cars so they produce impressive performance while meeting emissions, fuel mileage and noise standards. No area of the car is immune from these limitations, including the induction system. Checking off all those boxes means making a few compromises, but that’s where the aftermarket comes to the rescue.
In the case of the induction system, one of the most popular cold-air induction systems produced for late-model Mustang is from JLT Performance. The company got the jump on designing a kit for the Coyote engine in the 2015+ Mustangs, and they haven’t looked back except to tweak the system with some minor upgrades.
As you know, aftermarket cold-air induction systems replace the factory sealed air box, its internal panel air filter and the ribbed hose that connects the box to the factory throttle body. In place of this system, JLT Performance adds its larger-diameter tube capped by a free-flowing conical filter that fits inside an air box, that seals that box to the hood and joins with the factory fresh air duct via scoop behind the front grille.
You might assume that the system from the 2011-2014 Mustangs might carry over to the latest pony car. However, there were significant chassis upgrades and a revised induction system designed to fit under the lower hood that required JLT to create a unique system for the 2015+ Mustang GTs (the company also offers systems for EcoBoost and V6 S550s).
One thing that we wanted to do differently on the ’15 than we did on the previous models was allowing the throttle body end to be larger for future larger throttle bodies.—Jay Tucker, JLT Performance
“We use a reducer to go from the tube to the factory throttle body that actually creates a Venturi-effect, which is more ideal than a tube that meets the throttle body perfectly,” Jay added.
Freed from the limitations of the factory engineers, JLT can focus on simply improving performance. The open-element air filter also contributes to a more performance-oriented personality from the engine courtesy of more induction noise.
Improving the Flow
What’s In The Kit?
- PN CAI-FMG-15
- JLT plastic intake tube
- Silicone reducer
- 5×8-inch S&B Powerstack air filter
- Heat shield with duct
- Heavy duty clamps & hardware
As we mentioned, JLT was the first to produce and sell a cold-air induction system for the latest Mustang GT. Though the system was a hit right out of the gate, Jay and his team have continued to tweak its features to deliver the best possible performance, including adding a seal at the inlet tube to air box junction to further isolate the filter from the engine compartment.
“Sitting still for about 20 minutes in testing, we saw a 10-degree temperature difference (without the seal), so it actually was cooler under the hood,” Jay said. “And, driving around, in city traffic we noticed that it would take longer to creep up and it would cool down faster. It actually did benefit and people are buying them (as a retrofit upgrade).”
To try out the latest iteration of the JLT system, we turned to Coastal Chassis Dyno and a pristine 2017 Mustang GT owned by a regular customer. When we arrived, the car was stock save for a few suspension bolt-ons. Sam Lippencott baselined the stock configuration before Coastal’s master technician Steven Harris installed the JLT CAI.
With the new system in place, Sam dialed up a custom tune for the JLT-equipped Coyote. Because the air volume and velocity is different with the new induction, the mass air transfer function must be adjusted. Of course, if you are tuning, you might as well optimize the combination. In this case, the 2017 Mustang GT is much like its 2015-2016 predecessors, so Sam knew just what to do.
Tuning It Up
“There’s not really anything different from ’15 on up. They really haven’t changed anything,” Sam said of the calibration he created using HP Tuners software. “Basically transfer function, timing, cam timing and everything typical to a normal tune.”
Install Tools Needed
- 5/16 nut driver
- 10mm socket, ratchet, extension
- T-20 Torx driver
- Phillips head screwdriver or 7mm socket
“On a cold air and tune combination that’s usually what you pick up,” Sam said. “You may or may not see a bigger difference between dynos and tuners and stuff like that. Everything that I do, I do hot. I don’t do anything cool, so it’s easy to pick up another 10 or 15 if you let the car cool off.”
We certainly left impressed by a brand-new Mustang putting down over 400 horsepower at the wheels with only one mod and a matching calibration. More impressive yet were the gains under the curve.
“We typically see 30 horsepower,” Jay said. “I have seen 30-plus eight or nine times. That car started out strong, so it only picked up 15 peak, but it picked up a ton throughout…”