Mitchell's Mauler

It doesn't take more than a casual glance at Bill Mitchell's '34 Ford to conclude that it is a state of the art street rod. But frankly, there are lots of those around, so what's so special about this one? The answer is: It was built to look like a street rod and perform like a contemporary sports car. It wasn't built to just look impressive, but to perform impressively as well; every component of the car was selected accordingly. It has independent suspension to make it handle (not just because it's trick), a big-inch small-block to make it go like a bat out of hell (not just so it sounds mean idling around a fairgrounds), and huge NASCAR-style brakes to haul it down from speed (not just to fill up the trick wheels). And best of all, Mitchell put his car to the test for us to prove it's every bit the bad boy it appears to be.

As the head of World Products, a competitor in the NASCAR modified circuit, and involved with automobiles in all shapes and forms for more years than he'd care to admit, Mitchell is no stranger to high-performance vehicles. He's also had a string of street rods and, like many of us, about the time he was done with one he was thinking about another. Case in point, his recently completed '34 sedan was a great car, and with big-block power it was fun to drive, but it simply wasn't enough of a hard-core hot rod. What he decided he wanted next was an East Coast-style chopped and channeled, bad to the bone three-window that drove like his race car. Sort of a NASCAR coupe if you will.

As Mitchell tells the story, after looking at the reproduction bodies on the market he became somewhat disillusioned and started to think the project was not to be. But then he happened to bump into Del Austin right after the 2000 Street Rod Nationals. At that time Austin was working for Total Cost Involved (he's now on our masthead as Group Sales Director). As they killed time at the airport, Mitchell began describing the car he wanted to build and the frustrations he faced, particularly in regards to finding a channeled coupe body. Austin said he knew someone who might build just what Mitchell was after and introduced him to Redneck's Joe Godwin, who was also waiting for a plane. It just so happens Godwin raced an alcohol Funny Car so he was familiar with Mitchell and World Products, and the bench racing began. By the time everyone was ready to board their respective planes, lots of stories had been told and each had a bunch of scribbled notes on Mitchell's coupe. Godwin and Total Cost Involved would both participate in the project.

By the fall of 2000, Total Cost Involved delivered a custom chassis pinched 3 inches at the firewall and 6 inches at the nose. As this car was to be extremely low, and the front was dramatically narrowed, the mounting points of the suspension had to be moved and special control arms 3 inches longer per side fabricated to maintain proper geometry. Meanwhile, Godwin was busy building a body with a modified floor that dropped it 5 inches over the frame up front and 4 1/2 inches in back. While he was at it, 2 3/4 inches were taken out of the roof.

With the body and chassis fabrication finished, Mitchell called on his lifelong buddy, Arty Tappen of Tappen Enterprises, to help with pre-assembly. Once everything was fit, the car was disassembled and Mike Stawicki stepped in to finish the bodywork and paint everything. Then it was back to Tappen for final assembly. Another longtime friend, Dondi, of Dondi Interiors, stitched the upholstery.

Wringing It Out
Mitchell's coupe was shaping up to be a unique car, but there was still a ways to go. As might be guessed, to achieve the performance goals set forth for this car, some serious horsepower would be required. But rather than a temperamental semi-race engine, the coupe has an off-the-shelf World crate motor under the hood. Granted, it's a 605hp, 454ci small-block Chevy crate motor, but it runs on pump gas, isn't difficult to live with, and all indications were it would deliver impressive performance. But we wanted to see some real numbers, so Mitchell obliged us by taking the car to the track. The numbers the car posted were indeed impressive; 0-30 mph in 1.78 seconds; 0-60 mph in 4.00 seconds; 60-80 in 2.15 seconds. The quarter-mile stats, an 11.98 e.t. at 116.06, were recorded in street trim. And although a four-link adjustment would have dropped the elapsed time, Mitchell chose to run the car on the strip in the same configuration it gets driven on the street.

One of the keys to any automobile's flexibility is the gearing. It has to be low enough on one end to launch the car, and high enough on the top end to allow highway travel at reasonable engine rpm. For that reason Mitchell chose a Richmond six-speed coupled with a 9-inch Ford rearend with 3.29:1 gears.

Of course, if a car is capable of accelerating quickly, it needs to be able to slow down effectively. Thanks to Wilwood discs at all four wheels, Mitchell's coupe posted some impressive numbers in that department as well; the best 0-60-0 braking test revealed the coupe would go from 0-60 mph in 4.85 seconds and from 60-0 mph in 3.28 seconds for a total time of 8.13 seconds.

A Few Handling Tips
As a result of his involvement with racing, Mitchell has learned a lot about making cars handle. One thing he is adamant about is that, regardless of who built the chassis, for optimum performance it has to be "tuned" to the specific application. In most cases, including this one, tuning the suspension is really a matter of selecting the proper springs, as altering geometry is normally not done.

While this car has coilovers, to select springs of any type it's necessary to know how much weight they are supporting. To determine that, it's necessary to find out how much weight is on each axle. Mitchell went so far as to weigh the car at each wheel since he does it with his modified regularly, however, in most cases, weighing each axle of the car will be adequate. Ironically, in Mitchell's case he found the weight distribution of the coupe and his race car were identical, 47 percent on the front wheels, 53 percent on the rear. The coupe weighed in at 2,738 pounds total.

Normally, when coilovers are involved, if you supply the manufacturer with the wheel weights and shock angles, they will provide the appropriate springs. But one of the problems with coilovers that Mitchell loves to point out is spring bind, the condition that exists when the coils of the spring touch each other and they have all the bounce of a solid block of steel. Generally, this happens when the springs are too soft and the adjusters on the coilovers are turned down in an effort to establish the proper ride height. Now, note the springs on this car, there's plenty of room for the coils to work. With roughly 642 pounds on each front wheel and shocks that measure 13 1/2 inches extended, 10 1/2 inches compressed, and 12 3/4 inches at ride height, Mitchell chose 10-inch long springs with a 550-inch/pound rating (550 will compress the springs 1 inch. In back the shocks are 18 1/2 inches extended, 12 1/2 inches compressed, and are 16 1/4 inches at ride height. They were fitted with 14-inch long, 200-pound springs).

So, how did Mitchell decide on these particular springs? He has a surprisingly simple method. With the car supported by a jack at ride height he starts out with a given spring, say one rated at 300 pounds. With the adjusters seated against the spring the spring is measured, then he lets the car down to the point where the jack no longer carries any weight and measures how far the spring has compressed. Say it's 2 inches, in that case 300 x 2 equals 600, so he would use a 600-pound spring. This method takes into account the angle of the shock, or the moment ratio, which is the difference between how far the suspension moves and how much the shock is compressed. The length is determined by simply measuring between the spring seats with the suspension, and the shock, at ride height.

Another trick that Mitchell shared with us has to do with the rear four-bars or, in this case, a four-link. Basically, the difference between the two is this: With a four-bar the upper and lower links are fixed and parallel. While this offers the least resistance to suspension movement, it's not the best for weight transfer and has a negative impact on traction. On the other hand, the angle of the bars of a four-link are adjustable, and are often closer at the front than at the rear. In a nutshell, this is how they work. Think of two lines drawn along the upper and lower bars. Where they meet is the length of the lever the rear end has to try and lift the car under acceleration. In the case of a parallel four-bar, the lines never meet, but now imagine the angle of the upper and lower bars of a four-link are such that the lines meet at the bellhousing. Under acceleration the four-links try to lift the car at that point and weight is transferred to the rear wheels.

Unfortunately, there's also a down side to four-links. When the bars are at an angle, some binding takes place, so suspension movement is hindered to a certain extent, and the greater the angle, the more this becomes a factor. On the other hand, four-bars don't provide the rear end with any significant leverage, and consequently no weight transfer, but they will make the car ride better. Mitchell decided to split the difference and sacrifice some ride quality for traction, but while the coupe uses an adjustable four-link, the bottom bars are level, and the uppers are only slightly closer at the front pivot point than at the rear; 6 inches and 6 1/2 inches respectively. This was the best compromise between ultimate traction and the best ride and handling. And if Mitchell changes his mind, with the adjustment available, he's able to skew the car's performance one way or the other.

While there are many street rods that look the part, few of them will perform at the level of this '33. Fewer still are offered up to us to put through actual testing. With the bad boy look and the near Viper-level performance, this car fulfilled all Mitchell's expectations. Of course, it does make us wonder what he's going to do next.

World Products at a Glance
Although Bill Mitchell's World Products is known for performance parts, they are also the leading supplier of cast-iron replacement heads for the general automotive repair trade. But what's really interesting, they are also becoming a source for what most of us thought there would never be a shortage of, the venerable V-8 engine block.

World has been producing big- and small- Chevrolet blocks and heads in cast iron and aluminum for some time. Thanks in great part to them it's possible to build a Chevrolet engine without a single factory part. Soon, that same capability will be available to Ford fans, and someday Mopar aficionados.

Thankfully for automotive hobbyists, while the OEMs are looking at phasing out the V-8, World is looking at ways to make them better for us. Basically, that's accomplished by making the cylinder walls thicker to accept larger bore sizes and reshaping the crankcase to accommodate longer strokes.

Along with individual parts, a few years ago World introduced a crate motor program. All the engines are individually assembled and dyno tested. However, before the engines are fired, they are filled with oil and the lubrication system is pressurized. Then they are run for approximately 45 minutes with light tension valve springs to break in the cam. After the cam and lifters are run in, the valve springs are changed and the engine is leak tested for ring seal and checked for proper compression ration with a NASCAR whistler. The engine then gets a series of long dyno runs to test power and calibrate the fuel system. All testing is done on a Stuska engine dyno and data is corrected to SAE HP.