POCKET ROCKET

Balancing Power and Practicality in Design

He couldn’t decide whether he wanted to build a straight-line runner or a corner carver capable of scorching the clocks at high-country slalom events. Or, quite simply, he could build himself an emissions-legal, high-country pocket rocket that gets exceptional fuel mileage and can haul the kids and the family dog. Seyfer burned the midnight oil and came up with a way to have it all. The result is a 4.6-liter, DOHC Cobra engine mounted in a refurbished ’01 Ford Focus that runs the quarter-mile in the 12s and gets 28 mpg.

Creating a High-Tech Adjustable Suspension

When designing this car, it became blatantly obvious that with this kind of power on tap—320 hp at 6,600 rpm and 317 lb-ft of torque at 4,750 rpm—both car and designer would approach a performance threshold which, once crossed, would produce an expensive, tire-smoking mechanical curiosity capable of delighting all those who saw it, drove it or rode in it, yet be of little practical use for anything else. Applying the experience gleaned from years of working on high-­performance muscle car suspension systems, Seyfer decided that the key to having both was to design a high-tech suspension that was fully adjustable in all facets. Also, he had to get as much tire under the diminutive fender of the Focus as possible without compromising the outward appearance and originality of the vehicle itself.

Keeping a Low Profile with Sleeper Appeal

The word “sleeper” comes to mind. “I can’t go five blocks from home without having one of the young local kids try and race me with one of their Hondas,” commented Seyfer with a huge grin.

Innovative Torque-Arm Rear Suspension Design

With limited working space under the Focus, Seyfer came up with a “short” torque-arm-design rear suspension. However, the shorter the toque arm, the more likely you are to experience rear wheelhop when you mash on the brakes. “Master machinist Greg Perrin and I created a spring-loaded device to decouple the torque arm during extreme deceleration and braking. This practice is fairly common with the dirt track crowd, and it adapted well to the Focus rear suspension. Exhaust system clearance is also at a premium, which meant that when installing the 3.73:1-geared, 11-2/8-inch Ford Explorer disc-brake-equipped, Mark Williams-narrowed 8.8-inch live rear axle, a modified Watts Link was utilized rather than a bulky Panhard bar to locate the rearend.”

Two-Piece Driveshaft and Enhanced Vibration Control

You might wonder why this short-wheelbase Focus uses a two-piece driveshaft, which is more commonly used on much larger vehicles. “The reason for that is in order to allow the 4.6-liter, DOHC Cobra engine to sit at a three-degree angle while the pinion actually sits higher than the Borg-Warner T-45 output shaft. This avoids losing some of the backseat area. Research indicated that many of the vibrations present in torque-arm-equipped vehicles is generally caused by conflicting arcs in the rear suspension and driveshaft. So by creating a two-piece driveshaft the same length as the torque arm itself, the problem is resolved, resulting in a vibration-free ­drivetrain.”

Advanced Rear Air Spring System for Improved Handling

Seyfer also designed a computer-controlled rear air spring system, which allows the vehicle to have more than 6 inches of suspension travel at the rear, a critical component in keeping such a high-horsepower car glued to the pavement. Through careful optimization and design, Seyfer was able to “tune” the airbags and the AFCO rear shocks to provide amazing handling, even in a torque-arm environment where the practice has always been to overspring the vehicle at the rear to loosen things up. So effective is this suspension that Seyfer claims his Focus will not bottom out, even on autocross tires with tools and a cooler in the back.

Front Suspension Modifications and High-Performance Brakes

The front suspension on the Focus features a modified version of the Kugel Komponents-designed front crossmember, utilizing Kugel tubular lower control arms, Energy Suspension polyurethane suspension bushings, a pair of fully adjustable KW coilover front struts and SVT Focus front spindles with Ford Prove front hubs and SVT Mustang Cobra 13-inch four-­piston front disc brakes. The car also uses a custom 1-1/8-inch tubular front antisway bar and ’98 Mustang Cobra rack-and-­pinion steering. Wheels and tires come in the form of a set of 18×8.5-inch F&R racing two-piece modular honeycomb wheels rolling on P255/35SR18 Avon radial rubber.

Engine Installation and Transmission Modifications

Once the stock 4.6-liter, DOHC SVT Mustang Cobra engine was mounted at an acceptable angle, it was apparent that the Kugel Komponents front crossmember would interfere in the use of a cable to release the clutch. A McLeod hydraulic throwout bearing works great with the Focus clutch master cylinder. However, Seyfer relates that the pedal rate is slightly higher than the stock Focus, but not at all objectionable. Shifting of the Borg-Warner T-45 five-speed transmission also required some creative engineering. It seems as though the shifter on the T-45 wound up coming through the floor about 8 inches ahead of the position of the OE shifter hole in the Focus console, so Seyfer and Perrin machined a remote shifter to cure the problem.

Merging Mustang and Focus Electronics

Adopting the vehicle’s tricky electronics involved marrying the Focus and Mustang electronic components using the original Focus network. “While many of Ford’s networking protocols are standardized, the Focus and Mustang electronic instrument clusters work very differently,” commented Seyfer. To compensate for this, Seyfer integrated the Mustang passive antitheft system and hybrid electronic cluster into the Focus network and set the Mustang gauges in the Focus cluster, which now receives its commands from the remote-mounted Mustang cluster. Seyfer also had to relocate the Mustang gauge layout on a new faceplate for the Focus cluster. The original Focus central timer module and restraints control module were easily adapted to work with the Mustang PCM and HEC. The Focus also has a fully functioning emissions control system that includes the evaporative system. Working from SAE (Society of Automotive Engineers) white papers, the fuel tank was designed to take maximum advantage of the limited space available behind the rear axle, and to provide the best control of fuel vapor. Amazingly, the Focus is still able to carry 12 gallons of fuel, along with a rear-mounted battery located under the floor pan!

Exterior and Interior Enhancements for a Custom Look

The 120,000-mile ’01 Focus originally came out of Chicago and, according to Seyfer, “For being only three years old, it was in pretty rough condition. I replaced every panel but the roof, hood and doors with new Focus RS body panels. The bumper covers came from a supplier in Germany and were advertised to fit the RS parts. However, I wound up cutting up the rear bumper into three pieces and had to rework it extensively to fit the contours of the RS rear quarter panels. I also installed a set of European Focus RS headlights and SVT Focus door handles. Then I applied a fresh coat of PPG GM Omaha Orange with a gold and platinum pearl overlay.”

Enhanced Interior Features for Comfort and Safety

Aside from the aforementioned Seyfer-designed flamed orange dash cluster, the interior of the Focus features a Seyfer-installed 12-point rollcage along with plenty of sound-damping material throughout. You’ll also find a pair of Autoweave Upholstery-covered Recaro SRD bucket seats and an Alpine stereo with iPod controls.

Driving Experience and Final Thoughts

“Driving this car is lots of fun. With the engine in stock form the vehicle can be driven very smoothly if you so choose. With a power-to-weight ratio in the 9.7lb/1hp range, traction can definitely be an issue if the driver over-squeezes the throttle. Handling is razor sharp and the car is just loose enough that in the hands of an experienced driver it pivots very easily into the turns. On a trip to Las Vegas last November to attend the SEMA Show, the Focus averaged 26 mpg, which is two mpg more than a stock Focus, and that’s at alleged cruising speeds between 80 and 95 mph.