Egon Booms' Mercedes-Benz PontoonI have always loved Q-cars. The idea of putting a big, tricked-out engine into a small car, and seeing the look of surprise on the faces of sports car drivers as you leave them in the dust has its own brand of appeal. These days major manufacturers play this game very well indeed. BMW's M5 and the E63 AMG are just two examples of factory-built four-door hot rods that can really upset drivers of junior league supercars.
However, there's something even more enticing about dropping modern mechanicals into a classic car, giving it a turn of speed that would do justice to the racing cars from its era.
My old high-performance road and race driving coach, John Lyon, had a car like that back in the 1970s. It was a green Morris Minor Convertible powered by a tuned 110-hp Mini Cooper S engine. A lower Koni suspension, wider steel wheels and big brakes kept it from departing into the scenery, and were the only clues to its non-standard mechanicals. Of course Lyon was a master behind the wheel, and the number of big car drivers he upset with this innocuous looking but very rapid granny car was legendary.
Today I'm in the small village of Hinte, near the coast of Northern Germany, and I have come to see a 1950s classic Mercedes Ponton with the heartbeat of a 35-year-younger model.
The Ponton has a special place in my personal motoring experience because when I was 12 and living in Singapore, I was one of five youngsters taken to school every day in a grey 180D Ponton contract taxi. My lasting memories of this car was a clapped-out diesel engine that sounded like it was full of nails, and it felt like it could not pull the skin off the proverbial rice pudding. Forty-eight horses hauling a 2,600-pound car with six on board was no recipe for stirring performance.
Unlike some of the wild Frankenstein engine transplants companies like Brabus made in the 1980s, stuffing souped-up big-block S-Class engines into unsuspecting 190Es, this Ponton's creator, Dipl. Ing. Egon Booms, traded one four-cylinder Mercedes engine for another. However, his power unit of choice was not the tame 122-hp motor that powered the bog-standard 190E 2.0 liter. Instead, Booms went the whole hog with the 235-hp Cosworth-cylinder-head-endowed engine from the legendary 190E 2.5-16 Evo II.
Open the bonnet and you will see the cam cover bears the 2.3-16 script from the earlier 185-hp road car. "At the time I built it, this meant cheaper insurance," Booms explains, "but things have changed since, and it now no longer matters as the car is categorized as a classic and licensed for summer use in Germany." Interestingly, after inspecting it, the German transport office gave Booms manufacturer status; therefore his car has its own unique chassis number.
The high-revving 2,463cc motor is very over-square, with a bore and stroke of 97.3mm x 82.8mm. All DTM racers and their homologation road versions had to use fully working catalytic converters, and the 500 Evo II cars built for this purpose were no exception. So this late 1950s Mercedes meets mid-'90s emission standards.
Free-flow steel catalysts help the power, and a healthy 235 hp arrives at a screaming 7200 rpm, with the limiter at 7700 rpm. Torque output is 181 lb-ft between 5000 and 6000 rpm, and the 3.46:1 final drive helps the high revving engine at cruise.
When I first heard about this Ponton Cosworth, I wrongly assumed that Booms had simply performed an engine transplant and beefed up the chassis and brakes to cope with the near 300 percent increase in power. How wrong I was.
Wheeling out the photo album, he showed me the step-by-step build he performed in his spare time over seven years. He explained that his one-off special is actually the marriage of a Ponton bodyshell to the complete floorpan, axles, suspension, engine, brakes and interior of a 190E 2.5-16 Evo II.
Actually, it would be more correct to say two 190E 2.5-16 Evo IIs, as the first donor car had been hit hard from behind and provided its undamaged motor and interior. The second car suffered significant damage to its roof when it rolled, and was cannibalized for its underpinnings and some other parts.
"I actually started off with the idea of using a 122-hp 2.0-liter 190E motor," Booms explains. "But when my local wreckers told me they had an Evo II, I didn't hesitate." Not all the parts came from the two wrecked Evo IIs though. In the interest of safety, Booms used many new suspension and brake parts, which added to his final bill.
The Ponton body panels were repaired where necessary and adapted to the mix of original and 190E structure with many hand-fabricated bespoke parts. "Actually, only the roof panel was totally untouched," he says. Bespoke sheet metal around the 190E bulkheads and door support areas was hand fabricated to stitch the two generations of Mercedes together.
Those who have ever contemplated such a project will be savvy enough to ask about the wheelbase and tracks of both cars. But just as the 1970s Mercedes 600 and today's Maybach come within spitting distance of each other in critical dimensions, so do the Ponton and 190E. "If you want to be pedantic, the Evo II's wheelbase is exactly 15mm longer, so I just jigged things slightly to center the axles during setup," Booms says.
Open the boot and further surprises are revealed. The fuel filler cap sits behind an adapted 190E filler flap placed vertically up against the bulkhead, while a CD changer hangs on a bracket under the rear parcel shelf. Lifting the modern Mercedes-style boot floor panel reveals an OEM Mercedes-based satellite navigation unit that rises on its own miniature pneumatic strut for loading the CD. The attention to detail is simply awesome.
Most of the Evo II cabin was transplanted into the Ponton. "I had to shorten the dash slightly and fabricate a trim panel to make it look neat," Booms says. "The front and rear seats are all original Evo II as is the center console."
The engine stirs into life with the familiar frenetic rasp of the 190E 2.5-16 Evo II. This high-revver always sounds highly strung and raring to go, a soundtrack that seems totally at odds with the sedate look of the classic Ponton.
On the road, Booms' creation feels just like an Evo II. Its medium weighted power steering, taut but supple ride and crisp handling are a world away from the late-'50s Ponton. It even has ABS. No Ponton has ever gone this fast, but this Mercedes hybrid is capable of 149 mph, and zero to 62 takes 7.0 seconds, a big improvement on the yawning 36 seconds of my school taxi.
The only visual clue that this car is not what it appears to be is the 7.5J and 8.0J x 16-inch AMG alloys with 225/45ZR16 Bridgestones and the lower ride height, but Booms is considering making wider original steel wheels with the appropriate hubcaps to complete the deception.
As an automotive engineer with master mechanic and automotive electrical master diplomas as well, Booms relishes off-the-wall challenges like this car. But it was not a cheap exercise by any means. "If you factor in my 2,500 man hours over the last seven years as well, then this hobby project would cost over 185,000 to reproduce," he says.
As I departed, he told me that he has already started work on his next project, a Porsche-powered, mid-engine classic Beetle. I'll be visiting again in the not-too-distant future.
Longitudinal front engine, rear-wheel drive
2.5-liter I4, dohc, 16-valve
Five-speed manual, 3.46:1 final drive
OEM 190E 2.5-16 subframe and assemblies
OEM 190E 2.5-16 assemblies
Peak Power: 235 hp @ 7200 rpm
Peak Torque: 181 lb-ft @ 5000 rpm
0-62 mph: 7.0 sec.
Top Speed: 149 mph