The annual Bonneville Speed Week is a place to find some of the most innovative engineering done anywhere, along with many of the fastest vehicles on the planet. Here is an inside look at how one team took an idea from sketches to a Salt Flats screamer.
“There are people such as myself who have decided not to own a bigger house and a Jacuzzi and instead build a land-speed car,” laughs Lon Miller, a self-taught engineer. Miller used to design commercial food-processing equipment for Key Technology, Walla Walla, Wash., and recently got bit by the Bonneville bug. “I knew right away that it had to be a 1953 Studebaker,” Lon adds. “Bonneville legend Gene Burkland raced a ’53 Studebaker, and his son Tom holds the world record at over 400 mph for pistonengine streamliners.”
A friend in Childress, Tex., located one of the cars in a field, rusted and shot full of bullet holes. Most people would have kept looking. But Lon and his son Rod are skilled welders and machinists who’ve built numerous circle-track race cars from scratch, so they felt up for the challenge. The rear body, doors, deck lid, and rear bumper were the only Studebaker parts saved from the rusted hulk.
From the ground up
Rod laid out a rectangular-steeltube chassis and fit the rear body to it. A dummy engine block placed in the frame located the lower engine mounts and plate. A fuel cell and coolant tank go ahead of the engine. A full roll cage was assembled off the car then raised into place and welded. The driver sits where the back seat used to be for better weight distribution.
Bonneville A/GCC (Unblown Gas Competition Coupe and Sedan) class rules say the contour of the car body from the cowl back must remain stock. “You can chop the top, which we did, but the body can’t be slanted in any way for aerodynamic advantage,” explains Lon. From the cowl forward is open to modification.
The nose started as a fiberglass Studebaker replica originally designed for an NHRA drag-racing car. Booked to it was another fiberglass section. The recontoured, extended nose improves aerodynamics and boosts down force, too much, in fact, as the Millers would later learn.
In an effort to cut drag, a smooth steel pan completely covers the underside of the car. The pan slopes upward at a slight angle starting behind the rear axle and going to the rear bumper, a well-known trick among racers to boost down force and smooth airflow exiting the rear of the car. Rear flow straighteners, roof rails, and an adjustable rear wing round out the aero package.
The A-frame coil-spring front suspension and rack-and-pinion steering gear come from a 1970s Ford Mustang II. An intermediate step-down gearbox between the steering wheel and steering gear makes steering less sensitive to control inputs. “Driving at high speeds on the salt takes a light touch,” says Rod.
Apparently some drivers don’t have it, as evidenced by the number of cars that spin out each race day. Narrow, high-pressure tires tend to grip well. And bigger-diameter tires give better traction than smaller ones, and they drop engine rpm, both pluses. However, nobody seems to agree on the amount of tire-to-salt slippage. “I’ve heard numbers from 3 to 9%,” Lon says. “We compensate for slippage with gearing.” A 9-in. Ford rear end with a Watts linkage contains 2.47:1 ring and pinion gears from a 1970s Lincoln. The gearing is considered tall, but accounting for loss of traction, it may still not be high enough to go for record speeds.
A one-off, quick-change gearbox helps compensate for tire slippage. Two sets of spur gears from Winters Performance Products Inc., York, Pa., go in a housing that was NC milled from a chunk of aluminum (scored for cheap on Ebay). The bearings and shafting were sized by reverse engineering a four-speed transmission. The gearbox goes in-line between the transmission and rear end. It permits fine adjustments to the final drive ratio. There are simpler ways to do this, acknowledges Lon. A purpose- built rear end for drag racing or stock cars is a better choice. But they are pricey, and he wanted to keep costs down.
800 horses at a full gallop
With the body and chassis well underway, attention now turned to the engine. A GM Bowtie racing cast-iron big block got the nod. The special block is designed to be bored out more than what’s possible with ordinary production blocks. This aligned with the goal of building an engine with a relatively short stroke and large bore (over square). The geometry lowers piston speed and acceleration, important considering that the 500-cu-in. mill redlines at over 8,000 rpm.
Unlike drag racing, “An engine built for Bonneville must run reliably flat out for 5 miles at a time,” Lon explains. “It’s basically an endurance engine.” A sophisticated valvetrain comprised of titanium valves, roller rocker arms and lifters withstands the abuse. Trick aluminum racing heads from Dart Machinery Ltd., Troy, Mich., and a high-lift, long-duration camshaft help the big engine breathe and make maximum power at high rpm.
The exhaust valve heads are of a smaller diameter than the intakes, as in most engines. But the exhaust pushrods are fatter than those on the intake side to prevent the former from buckling under load. It turns out the camshaft’s extreme valve overlap opens the exhaust valves against compression pressure. The compression ratio is a lofty 14.5:1 to squeeze as much horsepower as possible from the thin air at the Bonneville lakebed. The combination of a 4,000-ft elevation and 100°F temperatures in mid-August can push density altitude above 5,000 ft. The high-compression setup, though effective, leaves little room at top-dead center between the piston and valve heads, and the combustion chamber. Spark plugs are rotationally indexed so the electrodes fit in pockets cut into the piston heads.
A massive four-barrel carburetor feeds to a high-rise aluminum intake manifold, drawing high-pressure air from a rear-facing cowl-induction scoop. Custom exhaust headers incorporate equal-length tubes that step up diameter in three increments before going to a large collector. The arrangement is said to improve scavenging of spent exhaust gases from the combustion chambers, and it promotes filling of the cylinders with fresh fuel/air charge. The Millers apparently are on the right track because dynamometer runs show the engine makes a healthy 800 hp.
The engine couples to a modified two-speed Powerglide automatic transmission, the same type found in 50s and 60s Chevys, but with the torque converter removed. Torque converters can fly apart at high rpm and maim or kill the driver, necessitating a blow shield to contain the debris. Ditto for manual transmissions with their heavy flywheels and clutches.
The only thing left connecting the engine and transmission in the Studebaker is a lightweight, steel plate with a starter ring gear. Rules mandate that cars start on their own without pushing so the ring gear had to stay. A push truck gets the car up to about 40 mph, at which point Rod engages a lever that sends hydraulic pressure to bands in the transmission, effectively locking the transmission gears to the engine crankshaft. The big-block Studebaker accelerates rapidly, leaving a salt cloud in its wake as it disappears over the horizon about 3 miles out.
Speed Week 2006 was the first for the Studebaker. A target speed of 225 mph proved conservative; the car went 238 mph. But the inaugural outing wasn’t without problems. First, the front coil springs were too weak. Aerodynamic down force fully compressed the springs at speed and ran the front tires into the wheel wells. Later in the week, a bronze bushing in the transmission tail shaft that supports the driveshaft burned up because it was never designed for these speeds. A switch to needle bearings solved that issue. So far, the updated transmission has worked well. But with only two speeds, engine rpm drops about 3,500 rpm when shifting to top gear, out of the narrow band where the engine makes maximum horsepower.
The down-force problem reared its head again in 2007, despite a doubling of the front spring rate and raising the front end 0.5 in. Officials eventually banned the car from further competition (until the problem is fixed) after the nose dipped into the salt surface at 235 mph, turning the Studebaker into the world’s fastest plow.
Disappointed but undaunted, the Millers are busy tweaking the car for Speed Week 2008. A three-speed 350 Turbo Hydramatic automatic transmission will sideline the old two-speed unit. They also traded the A-frame front suspension for a straight axle with a Panard bar and adjustable coil-over shocks. To wring even more power from the big block, compression will be bumped up to a staggering 16:1, near the theoretical limit for spark-ignition engines. The cylinder head combustion chambers were laser scanned to fit custom pistons to the contours.
The most noticeable change is a complete makeover of the fiberglass nose. Gone is the front splitter as well as a portion of the ramped upper fender surfaces, features that, in hindsight, helped generate the excessive front down force. The nose now resembles that of George Poteet’s radical 1969 Barracuda land-speed car Blowfish. Blowfish’s incredibly slippery 0.21 drag coefficient is the result of extensive wind-tunnel testing at Chrysler. The turbocharged, four-cylinder ’Cuda has already gone over 255 mph and is aiming at 300 mph, which would make it the world’s fastest door slammer. Lon and Rod hope to benefit from Poteet’s success and eclipse the current A/GCC record of 259.931 mph with their Wretched Excess Studebaker.