We’re back again with the second half of the wheelbase alteration process as we transform a humble 1963 Dart 270 Sedan into a wicked altered wheelbase tribute car. Last month we showed how we moved the rear axle and suspension forward exactly one foot. It was as easy as sliding a sheet of plywood into the back of a station wagon! But we can’t stop there. By moving the front axle centerline forward beneath the body of the car, we further maximize the weight distribution shift. You see, moving the wheels forward is the same as moving the engine back. And we all know that engine setback is a sure way to get more mass on the driving wheels (slicks) for improved traction. Take a look at any front engine rail dragster for the ultimate testimony of this notion.
Back in 1965 when Chrysler built the altered wheelbase Dodge and Plymouth A/FX fleet, engine setback was not on the menu thanks to the NHRA’s prohibition of such things in its strictly policed Factory Experimental class. So Chrysler moved the rear wheels forward 15 inches and the front wheels forward 10 inches and the rest is funny car history. Of course, the NHRA balked and disallowed them from class competition, but the cat was already out of the bag and racers soon discovered they could race their wacky altered wheelbase cars every single weekend if they wanted to at non-sanctioned “run what ya brung” match bash
While the very special factory-designed and -built ’65 Mopar FX fleet used an elaborate rework of the torsion bar independent front suspension, most non-factory match race builders – regardless of brand affiliation – turned to the elegant simplicity of straight axles and leaf springs. The advantage a straight axle has over an independent front suspension is that it never experiences camber, caster or toe changes. As a drag race car makes its way from the starting line to the finish line, engine torque and the effects of traction lift the body away from the wheels in often radical ways. With a stock type independent front suspension, the geometry wasn’t designed to cope and spooky handling often results. That’s all gone with a properly installed straight axle.
And by locating the straight axle to the vehicle frame with a pair of longitudinally oriented semi-eliptic leaf springs, the added benefit of increased ride height is made available. By lifting the nose of the car higher in the air, the mass of the body and engine is also lifted and this changes the center of gravity. The higher it is, the more of it will “topple” rearward when the rear tires start turning. But this is a double edged sword. Go too high with the ride height and handling, especially at the top end of the track, can be compromised as the rush of air beneath the floorboards tries to make the car fly. Lots of old school funny car pilots learned about aerodynamics the hard way, especially as they pushed over the 140-mph barrier. So don’t go crazy with lifting the car or it’ll become an ill handling barge in a jiffy.
Let’s show what it takes to stick an axle under the Dart. If you like what you see, you can either do it yourself or contact Dale Snoke at The Funny Car Farm in Monrovia, CA (626/256-0126, www.thefunnycarfarm.com) and he can do it for you.