Big B-Body Handling Upgrades - Rollin’ The Biscuit

Demonstrable Ride and Handling Upgrades for the Big B-Body

Ro McGonegal May 2, 2011 0 Comment(s)
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When the Biscayne was conceived in the late ’50s, the notion of handling wasn’t even an afterthought. People wanted big and powerful, never mind your face grease getting smeared all over the side glass on a swoopy turn. Besides, that entire trick chassis stuff was for European twinks, right?

1106chp 02 O  Big B Body Handling Upgrades 2/28

When I bought this car in 1997, Global West maestro Doug Norrdin said he would prototype everything that he’d developed for A-bodies on the Biscayne and if I’d be willing to leave it with him for six months he’d have it shipshape. I politely declined, under the illusion that the car would be finished and I’d be burning rubber by then. It took another eight years before it got to that stage.

My impetuosity ruled. I lost. Norrdin helped by inserting his inflexible sandwich of Del-a-lum (a billet aluminum core covered by a machined sleeve of Delrin) at either side of the front upper control arms and putting a spherical link on the frame end of the lower control arms. Rather than using two attachment points at the frame, the ’65-70 B-body lower control arms pivot on a single central locus. The front springs were unknown wire meant for a big-block application but with a coil hacked off the bottom to set the stance. Spring rate was anybody’s guess.

For the rear, Metco offered billet aluminum lower control arms that were originally meant for an A-body, adjustable (for pinion angle) on the top side and followed by more QA1s. I attached a PST bar to the lower links la the factory. Eaton supplied 2-inch drop (282 lb-in) lowering springs. Later, one end of the stock Panhard bar (keeps the axle housing centered beneath the car) was threaded for adjustment.

On the smooth expanse of the interstate, on the 800-mile shot from Memphis to my central Florida driveway, the car behaved normally, but on uneven secondary roads, the steering was so sensitive it was downright ugly. It trammed. It pulled. It took concentration to keep the car on the path over rough patches. At first I thought it a conspiracy of the 9-inch-wide Fikse wheels, grabby Goodyears, improper alignment, and quick 12:1 steering ratio. I didn’t discover until much later that the bar was actually riding against the frame (it passes through elongated oval openings), thus merrily steering the car quite independently of the driver.

Adhesion is good. Modern radial tires are so light-years better than the horrid bias-plies we used to suffer that they tend to turn an olden-day suspension into melted wax. The geometry, mainly caster angle, is all wrong. The object is to keep as much tread on the tarmac as possible at all times, and most modern performance road rubber has better tractive qualities than race tires used to have. To take full advantage of them requires a suspension system that responds in kind.

Norrdin emphasized that his B-body conversion is meant to remake the ride, handling, and steering for the street and not necessarily for autocross work. It’s for a purely fun ride: You can look down that flight deck of a hood and remember how horribly the original contraption worked. Before I ripped the wheels off it during the last century, I had driven the stock configuration less than 30 miles.

The Global fix begins with CTA-50A upper control arms that incorporate different geometry than the factory arm. To complement, the lower CTA-50L units are fitted with a rotating polyurethane cushion that allows the spring to index in the frame as well as the lower arm. B-bodies used strut rods attached to the lower control arm and the frame. Global’s ASR-50 adjustable strut rods eliminate fore-and-aft wheel movement (which directly changes the caster and toe) during braking, acceleration, and cornering and is accompanied by vague steering feedback.

At the rear, the TBC-51 upper control arm allows for the correct pinion angle without using shims. The spherical bearing on the frame side allows for the twisting action of the arm when the rear passes over bumps and as the body rolls. Companion to it, TBC-50 lower control arms provide smooth movement over bumps and reduce lift on the inside tire during cornering.

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