Ford Broncos Dominate 4400 and 4600 Class in Ultra4 San Felipe 250

Posted on May 25, 2021

When the stock 4600 class Ford Bronco race truck was shown at King of the Hammers earlier this year, we noted that they had upgraded to Wilwood brakes. When you have the money and engineering might of Ford Motor Company behind you, you can choose any supplier you want. Knowing that the top machines in the 4400 class have been running Wilwood brakes, they came directly to us and specced the same system the Unlimited class winners were using.

The Bronco R 4600 race truck uses our Aero6 6-piston caliper brake system, with oversized 14-inch GT36 straight vane iron rotors. This is the same setup used by Campbell Enterprises on their 4400 unlimited cars and many other top teams.

Brad Lovell - Stock 4600 Class

Brad Lovell won the stock 4600 class at San Felipe by nearly 10 minutes over the next fastest truck. The win was not all that surprising, seeing as Brad had qualified with the fastest time over the course just a few days before. Both results are stunning, considering that this was the debut event for the 4600 class Broncos.

Despite the name of the class, these are far from the Broncos you can buy, but they are required to retain a lot of the stock vehicle to be in the 4600 class. These trucks have to utilize the stock frame/unibody, a factory engine, and transmission (though modifications of these are allowed), and 35" tall DOT-approved tires.

Loren Healy - 4400 Unlimited Racing

The 4400 class is exactly as it sounds, unlimited. However, that means the trucks are faster, and it is a constant arms race to have the best setup around. Loren Healy, who was co-driver in the winning Baja 1000 KoH class car, won by less than a minute over the course of the 3-hour race.

Under the narrowed Bronco nose is a Ford Windsor-based 460 cubic inch engine with plenty of power and torque. At each corner are massive tires with a 40" diameter. The custom-built tube frame chassis features about 20" of travel at both ends. But the brakes are the same Wilwood Aero6 calipers we sell in many of our big brake kits, upgraded for racing with Thermlock pistons.

Here are some more pictures of the Broncos kicking up dust, courtesy of Ford Performance and Ultra4 Racing.