Unless you've lived under a rock in the farthest corner of the Earth these past few years and have no idea about performance (or you drive a Camaro--same thing), then you've heard of and probably have seen Hermann Stolzenberg at many race events. Throughout the years, he has built various street cars and immersed himself heavily into the heads-up 5.0 racing arena, and he did so when going nines was considered fast in Pro 5.0.
Needless to say, Hermann's years of Mustang drag racing have taken him down multiple roads, including opening his own business in Crofton, Maryland, aptly named Horsepower by Hermann. Even though his two Outlaw race cars garner the most attention, we decided to look into the other side of Hermann--a kinder--shall we dare say, gentler--side of the Herminator who likes street cars.
As with most 5.0 nuts, Hermann's bend on performance was primarily dragstrip-related, but there was still a strong emphasis on street use. This was where his clientele played and, quite frankly, where it was sometimes less stressful and more fun. When the '03 Cobra hit the scene, it was a no-brainer for a supercharged snake to make its way into his garage. As Hermann explains, "I bought my wife a new Sonic Blue '03 Cobra convertible. I put on all the usual bolt-ons, then the Kenne Bell went on. After seeing how much power and performance we were getting, I needed my own."
But it wasn't all about raw power. Hermann was enamored with the total package, which included smooth driveability, rock-solid durability, and suspension and brakes that would have the best from Europe running for the mountains. He perused the Internet, and a few weeks later found a super-low-mileage '03 Cobra hardtop.
Although the factory six-speed is a plenty-strong piece, Hermann didn't take a particular liking to it. Knowing the potential of a blown engine that sits in front of an automatic trans, he quickly assembled the list of parts required to convert his Cobra to an automatic. Wanting to maintain driveability, Hermann used a 4R70W to preserve computerized control and to keep the highway-friendly Overdrive gear. The 4R70W trans is a direct bolt-in, attaching to the backside of the Cobra motor without an adapter plate and maintaining a factory-type conversion. A Performance Automatic shift kit and flywheel help fortify the transmission package, but the big player is the Precision 4,800-stall converter. It allows Hermann to get right into the sweet spot of the 4.6 that now has more breathing room upstairs, thanks to the 2.2-liter Kenne Bell huffer.
The next big surprise is in the back end. A street/strip Mustang isn't complete without a solid rear, so Hermann swapped out the IRS and installed a tough-as-nails, solid 8.8. Not only did he gain a bunch of flexibility for traction, but he also lost a good number of pounds in the process. To control the housing, he installed Ford Racing uppers and Metco lowers into the existing torque boxes. A stock rear GT sway bar was bolted up, and a custom driveshaft from A-1 Driveshafts was put inside a Metco safety loop.
So what does all this translate to? How about 10.60s at 131 mph from just "bolt-ons?" We're not talking transforming a car here, just optimizing the factory setup for street and strip. Although a tranny swap and a solid rear-axle conversion may be more than the average Joe can handle, no internal engine parts were touched, and the car is still driven daily with many factory Ford components, giving new meaning to the term 10-second street car.
Gone are the days of frantic camshafts and touchy throttle response. Thanks to modern 4.6 performance, owning a car as capable as this is no longer a compromise in any sense. "I can use it every day," Hermann says. "It drives like a stock car, has a quiet exhaust, and is an unreal sleeper on the stock wheels."
There certainly aren't too many solid-axle, 4R70W Cobras out there, but we feel Hermann successfully demonstrated the best way to extract all the power the motor makes. Plenty of guys make big dyno numbers, but he's busy making it work.
The stock long-block benefits...
The stock long-block benefits from a Kenne Bell 2.2 blower with Metco 10-rib pulleys. Twin Focus pumps shoot a steady head of fuel to the 55-pounders by Siemens and get managed by the stock computer with Superchips SCT tuning. With 21 pounds of boost, the Bassani headers, X-pipe, and MagnaFlow mufflers do their best to let the blown 4.6 breathe. The T56 no longer sits behind the mod motor, as a 4R70W automatic transmission with a 4,800-stall converter by Precision sends the power rearward.
Notice how flat and perpendicular...
Notice how flat and perpendicular the rear wheels are sitting to the ground? That's because the IRS has been sent home, and the reinforcements now occupy the rear. A solid 8.8 axlehousing, replete with 3.73 gears and Strange 33-spline axles, transforms this Cobra into a more usable street/strip car. No more wheelhop, no more broken parts--just predictable traction, and plenty of it.
Auto Meter gauges sit neatly...
Auto Meter gauges sit neatly in the dash, while an XM Satellite radio system keeps the drive interesting at all times (as if a 10-second street car could be considered dull). A six-point rollcage by Woolford Brothers Fabrication (Glen Burnie, Maryland) was covered in the factory Sonic Blue color. The remainder of the interior is factory fresh and works perfectly fine, thank you.