Our 2020 Shelby GT500 Gets Ported, Cooled, And Dyno Tested!

Well, that last round of upgrades didn’t keep us occupied for long. If anything, it enabled our addiction and furthered our desire to create more power from the supercharged 5.2-liter Predator engine. We knew we would face this problem eventually, but we at least tried to avoid the lure of more horsepower by taking the necessary precautions of addressing suspension and tires first, to get the maximum efficiency from the chassis. However, once we sorted out the chassis we couldn’t resist any longer and the desire for more power became the priority. We started off with simple bolt-ons and baptized the GT500 fuel system in glorious E85. We thought we would be satisfied, but the white board in the shop had other plans and kept chanting, “More Power! More Power!” a call that we couldn’t resist.

In case you haven’t been following our 2020 Shelby GT500 build, it was a simple plan we sketched up. We wanted to create a street/strip car with as few modifications as necessary. We even tried to skimp on the suspension and see what Ford had created with its independent rear suspension. Unfortunately, it was paired for road racing and handling rather than launching off the line at what might be considered no-prep racing. After one-wheel hop and one-wheel spin we knew we had to dial in the suspension before requesting an increase in power.

GT500

Once we got the chassis configured properly with the use of BMR Suspension, Mickey Thompson tires, and a killer set of Forgeline wheels, we were able to step up to the plate with a host of bolt-on goodies. We added new Fuel injector Clinic injectors, JMS Chip FuelMAX EZ Fuel Pump Voltage Booster, JLT intake, Ford Performance Oil Separator, and everyone’s favorite supercharger modification: a smaller pulley from GripTec. After much success with such few modifications, we went back to our drawing board and crossed off the “Make Power” bullet point before proceeding to one of the final bullet points: “Make More Power.”

The Shelby GT500 5.2L Predator engine is a welcome mat to the house of horsepower. We knew this when our simple bolt-ons netted us a gain of 154 horsepower and 105 lb-ft of torque. However, moving forward we had to decide which path would net us the greatest gains, while still retaining street manners, reliability, and not put our engine in harm’s way. We know the price point to replace this engine and lets just say, we would rather not fork that kind of coin over anytime soon. We decided to take it easy and attack the intake air passageway and add some cooling capability into the mix. On the “Make More Power” bullet point we created a series of sub points that resembled a Christmas wish list. This wish list contained a Kong ported blower, Kong throttle body and a Whipple intercooler.

Ported And Performing

Porting a blower has been the best performance bang for the buck since the second generation Lightning and Terminator Cobra came onto the scene. It’s also one of the safest modifications that can be done. We simply had to send our supercharger unit to Kong for a port job, wait a few days, and install it back on the GT500 when the box returned.

While the practice of porting a blower has been around for decades, the reason behind it is extremely simple. The added air volume in the supercharger allows you to maximize the airflow, essentially creating a larger straw for the engine to suck from. This increase in air volume relieves stress on the supercharger and frees up horsepower that was bottlenecked in the stock unit. While we are not increasing the actual displacement of the supercharger, we are making it more efficient, reducing turbulence and avoiding heat build up.

“All the OEM manufacturers leave a lot of room for improvement on their superchargers. At Kong, we have the ability to optimize the ports using our five-axis machine. These port jobs are programmed in and are the same from stock cars to max effort builds,” says Greg Keosayian, owner of Kong Performance. “Every Kong port job is the same as we used on the fastest stock blower GT500 from Evolution Performance. The Repeatability ensures everything performs as it should.”

While making the decision to have our blower ported, we had Kong throw in its 108mm throttle body with our returning supercharger. The stock GT500 throttle body measured out to 92mm, but our goal was to optimize air flow and the stock flapper valve would have been yet another restrictor. This would not only closer match the ported blower, but would provide better throttle response and driveability. We would be lying to ourselves if we said that our focus was driveability and not huge power gains though.

When turning up a blower, an increase in sheer air volume becomes necessary. You need to increase the supercharger inlet, throttle body, and intake to avoid heat build up and engine stress. There is a huge correlation between inlet volume size and blower RPM to keep a supercharger as efficient as possible. Greg Keosayian

A gaping size difference between the stock 92mm throttle body and the Kong 108mm. The Kong 108mm throttle body is more than just a shiny flapper valve, its our way of reducing any more restrictions in the intake system.

A Chilling Tale

As we increased power from all directions, heat was becoming the bane of our existence. We cooled down intake air temperatures through the use of the JLT intake, but as the air was shoved down the superchargers throat the manifold air temperature was becoming increasingly warmer. Our stock intercooler had no chance of keeping up and resulted in a heat soaked intercooler. The stock unit lacked the cooling capacity needed for our build, which led us to our new Whipple super high density intercooler

The Whipple intercooler provided us with a much needed cooling abilities via its offset fin design and increased inlet and outlet water passage sizes. The billet inlet and outlet water passages are 33-percent larger than stock and allow the extraction of the heated fluid quicker. We upsold ourself on an auxiliary pump to assist in this process as well. The offset fin design allows more cooling ability for the same surface area, but Whipple used a bullet flange that provides a 10-percent increase in cooling coverage.

“When it comes to air to water intercooling, increasing the surface area of the core and water flow through it are two of the best ways to improve cooling capacity, efficiency and recovery times,” says Nick Purciello, product line director, Whipple Superchargers. “Increasing core thickness and fin density too much will produce a cooler air charge, but may inhibit airflow enough for an overall net loss in power. Conversely, too thin of a core and too little fin density will increase airflow, but the increase in air charge temperatures may produce a net loss in power due to a reduction in manifold air density. Our goal was to increase manifold air density without inhibiting airflow and we did it.”

The Whipple intercooler provides more cooling capacity over the same surface area as the OEM unit. However, utilizing a billet flange allowed Whipple to create 10-percent increase in cooling coverage. We added the optional dual pump system that allows an increase in water flow and faster recovery times when hot lapping.

GT500 Hits The Rollers!

After this stage of modifications, we had to verify that we could scratch out our last bullet point in good conscience. We strapped it down to the dyno and contacted our good friends at Lund Racing for a full retune. While everyone wanted a four-digit horsepower number, we decided to keep it on the conservative side, as replacement engine pricing loomed in our heads.

After a few passes were made, the screen displayed 940 horsepower and 664 lb-ft of torque. We actually lost 2 lb-ft of torque, but managed to gain an incredible 112 horsepower! The loss of torque was mostly due to the increased intake volume, but the horsepower gains and cooling abilities negate any loss in the torque department. I’m sure everyone will agree the torque versus horsepower exchange was well worth it – especially considering our difficulty with traction off the line.

Speaking of the drag strip, stay tuned for our final installment as we take our GT500 down the 1320 for the final results!

GT500

A jump for joy in horsepower. Our latest round of modifications increased our horsepower number from 828 to 940!

Photo gallery

VIEW FULL GALLERY >

 

More Sources

About the author

James Elkins

Born into a household of motorsport lovers, James learned that wrenching takes priority over broken skin and damaged nerves. Passions include fixing previous owners’ mistakes, writing, and driving.
Read My Articles

Blue Oval Muscle in your inbox.

Build your own custom newsletter with the content you love from FordMuscle, directly to your inbox, absolutely FREE!

Free WordPress Themes
Loading