Reaching new heights with Heidts Pro-G Wide-Track front and rear IRS suspension system for 1965-1970 Mustangs
Mustangs capture the American spirit. They’re iconic with a storied history on the street, strip, and in open-track competition. With that, there are many ways to enjoy your Mustang, from racing to showing to just plain old cruising. But if you own a classic and are looking for enough punch to battle with the latest computer-controlled iron, you’ll need a dose of hp and modern suspension technology.lured in for a closer look, the deal was immediately sealed, 'cause beneath the open hood of this upgraded utilitarian was what appeared to have been transplanted straight from a '67 Sting Ray-a 435hp Tri-Power 427. Or so we thought....
Giving This '67 Mustang a Performance Makeover
The stock suspension is nice for a jaunt around town, but for spirited driving, the 50-year-old suspension won’t cut it. Adding power and modernizing your suspension is the ultimate solution, and our performance prescription came from the team at Heidts Hot Rod & Muscle Car Parts in Lake Zurich, Illinois. Heidts is well known for its killer suspension systems, and we had the chance to follow the build and drive its own 1967 Shelby tribute Mustang. Last month in the February 2017 Mustang Monthly, we showed what goes into installing Heidts’ Pro-G bolt-in independent rear suspension (IRS), as well as details of its all-new front suspension for early Mustangs. This month, we take that same car to the track to test how it all works.
As we showed you last time, BlackDog Speedshop in Lincolnshire, Illinois, did the heavy lifting, removing the engine, driveline, and suspension. The crew also prepped the underside of the unibody for its Lizard Skin ceramic undercoat insulation and sound-control formula by Mascort Corporation of Houston, Texas. “We used a blue tint to color match the body,” Heidts’ Wallace Leyshon said. “That provided sound control and thermal protection, as well as great aesthetics.”
The ride quality of this ’60s muscle car was improved dramatically and the handling characteristics are on par with 5th Gen and other high-end performance cars,” Leyshon says about the Pro-G suspension. “That was our objective for the Project Shelby.”
With the body ready to go, BlackDog installed the complete Heidts front and rear suspension systems and the 5.0 Coyote engine, the complete custom exhaust, fuel system, cooling, and master cylinder, plus they custom-bent most of the lines and hoses. Bruce Couture of Modern Driveline assisted, fitting the Tremec six-speed and Quartermaster driveshaft in place. BlackDog mounted the Ford Controls Pack computer through the firewall, which added protection and a factory-like look. It set up the parameters of the ECU, and the Coyote was barking. “We cannot thank BlackDog enough for going above and beyond, ensuring a clean install and ultimate performance,” Leyshon says.
Fit and finish of the kit is simply amazing. The combination of the suspension and the American Racing VN 257 wheels (17x8, front and 17x9.5 rear with 4 1/4-inch backspace), wrapped in Nitto (P225/45ZR17 front and P275/40R17 rear) tires gave the Mustang a perfect stance. The Mustang now sits low and flat, but the question remained: Would it remain as flat and composed when pushed on track?
To find out, we put the Heidts Mustang to the test at Autobahn Country Club in Joliet, Illinois, sharing seat time with autocross specialist Danny Popp and Pirelli World Challenge veteran (and BlackDog Speedshop owner) Tony Gaples. “The Mustang was just terrific,” Popp says. “Its handling through the autocross turns was flat, and I could throw it where I needed to.”
Having driven the Project Shelby at Autobahn in its “before” condition, I was excited to see how much better it handled with the Heidts Pro-G suspension. I hopped in, clicked my belt, and cut loose. The 5.0L Coyote has endless revs and amazing power, and about 100 more hp than the pushrod V-8 that it replaced. But right away, I noticed how nimble and light the car felt.
The steering was precise and weighted nicely, which was a huge improvement over the stock power steering. I remember the factory steering being overly light and somewhat numb. Turn-in on the autocross was quick, but not to the point where the front end was nervous, and the Mustang exhibited a touch of body roll as it rotated around the cones. I enjoyed a high level of compliance with the tires, as they stayed flat to the pavement, even under hard cornering. This allowed me to cut in aggressively and put the power down hard and fast with no drama to speak of.
While I was hoping for a little oversteer to help it rotate on the tight autocross, the balance was more neutral, which is better for bigger tracks and sweeping corners. The team had the shocks in a stiffer setting, and even so, the ride quality was comfortable. A few clicks on the shocks would soften the ride for everyday driving.
As a purist, I respected the factory, period look for the interior, including the seats, Hurst shifter handle, and steering wheel, which connected to the rack via a sweet ididit column. Even the Digital Dakota gauges had a stockish look to them. And while I rolled with the top down, if things heated up, I could have flipped on the Vintage Air A/C unit and cooled off.