Lethal Performance’s GT350 cracks 500 horsepower with bolt-ons and E85
By Steve Turner
Fans of Ford performance are well aware of the marvels of the new Shelby GT350’s 5.2-liter Voodoo engine. Packing 526 high-winding crank horsepower, this naturally aspirated engine features a flat-plane crankshaft, high-flow heads, and more. Ford Performance engineers have already pushed the envelope of the engine platform that began as the Coyote back 2011.
When we covered the delivery and subsequent burnout of the Lethal GT350 at Weikert Ford recently we warned you that this car wouldn’t stay stock long. Here’s one last look before the modding began.
The question is how much more power is available by adding the traditional bolt-on parts and tuning? Fortunately we were able to sit in while Lethal Performance developed a bolt-on power package (PN LP-PWR-GT350-JLT-P-OR; $1,305.34) for the latest Shelby. With support from Lund Racing and Power by the Hour, the Lethal GT350 gained a JLT Performance cold-air intake, Lethal off-road mid-pipes, and tuning. After testing the hard parts and tuning on 93-octane pump gas, they switched over to E85 fuel to see how the combo responded to this high-octane pump fuel.
Using an nGauge tuner, Ken Bjonnes of Lund Racing developed a custom calibration to make the Shelby GT350’s PCM work in harmony with the new parts. Ken noted that the factory calibration was pretty good right out of the box, as evidenced by the strong baseline numbers put down by the Lethal GT350.
“We’re very happy with the results we got. Picking up 27 horsepower over stock is a very nice increase in power. Nothing like cracking 500 rear-wheel horsepower on a naturally aspirated car with minimal mods,†Lethal Performance’s Jared Rosen said. “What’s great about this setup is that it consists of such basic mods—intake, tune, and off-road midpipe—and works perfect with your factory fuel system. We’re making this same package available to our customers and I’m sure they’re gonna love it just as much as we do.â€
Power by the Hour technician Donnie Renfrow started the mods by removing the factory intake.
Perhaps the most striking modification of the bunch was the addition of the Lethal off-road mid-pipes. Removing the catalytic obstruction from the exhaust system not only freed up some power, it completely transforms the auditory personality of the GT350.
You can watch it run on the dyno right here…
“The car sounds really good from the factory, especially with the exhaust valves in Sport mode. However once we took the cats out and ran the off-road setup it’s a completely different monster,†Jared enthused. “It’s unreal how awesome it sounds now. I definitely had a huge grin on my face the first time driving it with the off-road pipes and nothing beats flipping that switch from Normal mode to Sport mode.â€
The GT350’s PCM seems to keep a close eye on the engine temperature, as power will drop off if it gets warm. As such, Lethal opted to install a cooler thermostat, which is optional in its power package. With the inlet out of the way, Donnie pinched of the coolant hose to minimize fluid loss.
It doesn’t just sound better. The Lethal GT350 is even more fun to drive. We took it for a quick spin and could immediately feel the extra power and torque as we banged through a few gears. Of course, Jared gets to drive it all the time, so the transformation was even more apparent.
“Without a doubt you can definitely notice the difference. The car screams already but definitely somewhat lacks a bit of that midrange power to get through the rpm quickly,†he added. “After the intake, tune, off-road pipe and some E85, that extra torque provided a noticeable difference in the midrange and really wakes things up. It was a fun ride home for sure.â€
Team Lethal plans to hit the drag strip and road course with this combo in the near future. After that, this GT350 is destined to see boost courtesy of a Whipple supercharger, so stay tuned.
Lethal chose one of Reische Performance’s hand-built, 170-degree thermostats, which are direct replacements for the stock units. Donnie disassembled the thermostat housing, swapped the ’stats, reassembled it, and topped off the fluid.Returning to the intake, Donnie swapped over these fittings from the factory air box to the JLT box.Then Donnie slid the JLT air box into place, mated it to the factory fresh air duct, and bolted it down.You’ll need to remove the mass air sensor from the factory inlet tube and swap it over to the 120mm JLT inlet tube.The JLT intake uses this silicone coupler to mate its massive inlet tube with the factory 90mm throttle body. This good news should you ever install a larger throttle body, as you can just replace the coupler and keep running the JLT.Donnie slips the inlet tube into the coupler, installs the air filter and tightens all the clamps before reinstalling the vacuum lines and plugging in the sensors to complete the installation.As you can see, JLT Performance paint-matched its intake Avalanche Gray to match the Lethal GT350. In addition to paint matching, you can order the intake tube in raw black or hydrodipped in various carbon-look colors. JLT also paint matched a set of coil covers for the car, which really help brighten up the engine compartment.Here’s a look at the finished install. As you can see, Lethal is running the dry filter option, but reusable, oiled filters are optional with the JLT intake.All finished topside, Donnie gets to work underneath, removing the stock cat pipes by unbolting them from the factory manifolds and unclamping them from the factory X-pipe after removing the oxygen sensors.After swapping out the stock pipes for the Lethal off-road mid-pipes, Donnie reinstalls the factory oxygen sensors.With everything lined up properly, Donnie tightens the manifold bolts and band clamps to wrap up the exhaust mods.
With all the mods in place, it was time to have Lund Racing’s Ken Bjonnes dial in the combination on the Dynojet at Power by the Hour in Boynton Beach, Florida.After testing the Lethal GT350 Power Package on 93-octane pump gas, Power by the Hour’s Jake Long drained the fuel tank so that Lund Racing’s Alex Flores could pour in a few gallons of E85.In stock form, the Lethal GT350 put down robust baselines of 473.44 horsepower and 395.89 lb-ft of torque at the rear wheels. With the company’s Power Package, the car cranked out 486.03 horsepower and 411.82 lb-ft of torque on 93-octane fuel. After swapping in E85 fuel and tweaking the tune, the car broke the 500 rear-wheel-horsepower barrier with 501.20 horsepower and 416.62 lb-ft of torque! That made for total peak-to-peak gains of 27.76 horsepower and 20.73 lb-ft of torque!While the graph shows some fat gains, it’s instructive to look at a sampling of the data across the range. You can see the gains are beefy down low and pull to a strong climax at the top of the tach.
WOW. Just WOW.