How Beefcake Put The First ProCharged S650 In The 8-Second Zone

An S650 rolls into the burnout box on a test ’n tune night, but beneath the distinct Dark Horse Blue Ember paint is a familiar sound. That whir is the straight-cut gears of a centrifugal supercharger built to feed an engine with an extra 1,625 cfm of airflow. 

I’m in love with the engine bay. I’m in love with the color. I’m in love with the interior. I’m in love with everything about the car. — Terry “Beefcake” Reeves, Beefcake Racing

After cleaning the tires, it stages, and the converter flashes to 4,600 rpm off the footbrake as the tree drops. The car’s front end lifts slightly as the substantial weight transfers rearward and the sticky tires bite. The 10-speed automatic bangs through the shifts at more than 8,000 as the modern Mustang sails down the track. Arriving at the timing shack, the driver collects the slips and celebrates the triumph with an NSFW exclamation.

That driver was Terry “Beefcake” Reeves of Beefcake Racing, and he carved his Mustang Dark Horse’s credentials into the internet micro record book as the first centrifugally supercharged S650 in the 8-second zone on the merits of the ProCharged machine’s 8.95 at 155.50 mph pass, which was hot on the heels of a 9.17-second rip during the Mod Nationals race in Georgia.

“My closest track closed due to temperature, so we had to drive the car almost 2 1/2 hours as we needed to stop and fill up with E85 before heading to the track to Kentucky Dragway in Clay City,” Reeves explained. “For a local track on a test ’n tune night, they’ve been doing an amazing job with prep on the track. We pulled into the track after a 2 1/2-hour drive, spent 15 minutes packing in and getting tires where they needed to be, and getting ready to make a pass. Then we spent about 15 minutes in the staging lanes before we ran, and 30 minutes off the street after a 2 1/2-hour drive, we had an 8-second time slip.”

Without any special cool-down or the use of supplements like methanol injection or nitrous, this full street car made good use of the intercooled centrifugal offered by a hearty ProCharger F-1A94 head unit, pumping out more than 24 pounds of boost.

“Our other ’24 car, which is currently the quickest S650 GT, has a Whipple on it. We wanted to do something different to showcase all the different brands that we offer at Beefcake Racing. I always pride myself on running what we sell,” Reeves explained. “We opted for the larger head unit mainly because I plan on pushing the car like we always do, and I don’t plan on cutting as much weight as we did with the GT, so I knew it would take a good amount of power to get into the 8-second range, as 4,400 pounds is no joke.”

No stranger to fast Mustangs or power adders, this combination was actually groundbreaking in another way. It was the first pony car with this power adder that the pilot had ever owned and raced.

“As long as we’ve been doing this, this is actually my first ProCharged Mustang,” Reeves confessed. ”We’ve had a ton of Vortech/Paxton. We’ve had a bunch of Whipples, and we’ve had turbo cars,” Reeves said. “I’m very familiar with centrifugals, just not the ProCharger brand, and when I say that we’ve installed hundreds of them with our partners and Finish Line, and I’ve sold thousands of them.” 

The aforementioned ProCharger F-1A94 is a top street-blower option for the standard Stage 2 system. It is further configured with straight-cut blower gears for that classic blower sound and a big red race blow-off valve that not only helps release boost when the throttle slams shut, but also sounds awesome when it does. 

“As far as the feel, it’s just like a centrifugal as I would expect it. You don’t get quite as much of a hit off the line as you do with a PD-type blower. However, you can offset that with a properly spec’d converter, which is what we do. Converters are the great equalizer when it comes to supercharging.”

The torque converter in question is a Suncoast Performance bolt-together unit with the aforementioned 4,600-rpm stall. It is part of a Finish Line Performance-constructed 10r80 10-speed configured with a Suncoast Category 2 trans kit.

“We probably have more experience with the 10-speed than just about anybody out there. We’ve worked with Suncoast on product development ever since the 10-speed came out. We’ve used the Category 2 kit and thousands of customers, cars, and probably six of our own,” Reeves said. “Brian (Campbell) up at Finish Line does an amazing job building these transmissions and using the Suncoast parts. The transmission is very strong. You really don’t break hard parts, but you do go through clutches. If you’re going to get out there pushing it, it’s important to put some good parts in the transmission.”

Of course, there is more to this combination than just a big blower and a built transmission. To ensure the combination was as durable as it could be, Reeves left the stock short-block in place, but made the obvious durability upgrades and a few while-we-were-there performance mods.

“One thing we always do is oil the pump, gears, and crank sprocket. With this being a stock engine, and the amount of boost we were going to be pushing, I just thought it’s smart to do head studs, and GT500 head gaskets,” Reeves explained. “Basically, with the same thing we would do on a built engine, pushing this kind of power, as head bolts are never gonna be up to the task for an extended period of time. I probably would not have ported the heads if we were not doing head studs, but since the heads were going to be off anyway, we might as well.”

Obviously, the four-layer, multi-layer-steel Predator head gaskets offer improved sealing under boost thanks to a thicker profile and additional sealing layers, and the ARP head studs deliver more resilient clamping force to ensure the cylinders remain sealed. Since he was tearing down the engine to the short-block, Reeves decided to enhance its performance as well. To that end, he topped the stock shorty with a ported stock intake and heads ported by AFS. The heads wear GSC valvesprings and stock cams under MMR cam covers, while the aforementioned oil pump gears and crank sprocket are from Boundary.

With the engine prepped to digest copious boost, Reeves uncorked the exhaust with Long-Tube Headers and an MBRP cat-back exhaust. He opted to fuel the Gen 4 Coyote 5.0-liter with Fuel Injector Clinic 1440 fuel injectors fed a generous flow of gas-station E85 by a Fore Innovations triple pump fuel system. To maximize the performance of the combination, he turned to Juggernaut Performance for a custom calibration created and deployed with HP Tuners’ software and hardware.

“Tuning is everything anybody can do, spark and fuel, but the transmission tuning is what separates the men from the boys,” Reeves said. “I see cars running half a second faster just because of good transmission tuning.”

The result of the right portfolio of hardware matched with the proper tuning resulted in a record-setting rip. With the durability upgrades on the top end, it is the ideal test case to see just how much stouter the Dark Horse short-block is, thanks to those factory-installed Predator forged connecting rods.  

“We have our GT in the eights as well. It is 550 pounds lighter, so it does make it a little bit easier, but I am curious how far we can push with the stock engine with the better rods in the Dark Horse. Honestly, I would never put a customer’s car out there with 1,100 wheel horsepower on a stock engine without them signing a waiver,” Reeves added. “But I have an RPG short-block on standby for whichever car goes first. As a business owner doing what we do, I’m always prepared. It’s not a question of if, it’s a question of when, although I would love to see this engine last for some time.”

It will be fun to see what the Dark Horse combination is good for, and Reeves is confident there is a bit more in the current combination. 

“If we stay this way, I think we could get an 8.80 out of it as it sits, and with a transbrake, an 8.70, possibly an 8.60. We would either need more boost or weight reduction to push it further,” he added. “There’s obviously a ton of places to pull weight, but we’ve already done that with our 2024 car, so we just wanna show customers different ways to do their builds  because everybody has different goals and needs.”