Torqued Up
Chassis stiffening for dummies - in an afternoon
by Richard Ehrenberg, SAE
Torque. It’s what turns the wheels, tows the trailers, raises elevators, runs the railroads - and, in excessive numbers, bends cars like rice-built tin toys and twists them like pretzels. We’ve all seen, or at least heard of, grotesquely buckled quarter panels and rippled roofs. Not a fun process, at least when it’s your car! With the uncaged, dead-stock chassis of our Bold Beeper mated to Ray Barton’s killer big-block, we smelled disaster waiting in the wings.
Now, normally, if you’re planning 10-second elapsed times, and you’ve got a few more active brain cells than we do, you’d cage your car. Or, at the very least, tie it together with a decent 6-point roll bar. Are we are simply not that smart? Probably - plus, we want our Road Runner to remain 100% streetable, and look as close to stock as possible. So a cage, or even a bar, is out of the picture. So what we did is to take a page - actually, a few pages - from the factory’s bag of tricks, old and new. In the first category, back in the mid-‘60s, Chrysler engineered an add-out for Unibody platforms that significantly increased torsional rigidity and generally firmed things up like a few dozen trips to the gym - without adding significant poundage. What they did, variously, on convertibles, cop cars, and Hemi-powered vehicles, was to add steel plating strategically located to increase the rigidity at the main chassis connection points: between the front and rear stub-frame rails and the rocker boxes, which are, in fact, the main frame members. Reinforcing the four weakest and/or most highly-stressed points in the car, these were added at the factory on a ‘detour’ section of the plant, because they needed to be welded in by hand - simple spot welds, which fasten nearly the entire chassis together, were both inadequate and impossible to do. That’s likely the main reason why all cars didn’t have them. Which is a shame.
Anyway, that was then. Now it’s the then - the third millennium. We’ve all driven modern cars which have a granite-like platform for the suspension to work off of. And, thanks to the engineers at Auto Rust Technicians in Cranston, Rhode Island, easy-to-install replica torque boxes are now available for your A or F body, as well as our Beeper’s B-bod. They are even better than the originals, being fabricated from 13-gauge cold-rolled steel (approx. 0.093") compared to the stock 16-gauge (0.062"). Installation takes just a few hours, as you can see in the accompanying hands-on photographs.
While we were at it, we scapped a page from the Green Brick Files - and added another modern-car feature - rail-through construction. In the old days, drag racers called these frame connectors, and they still do just that - tie the longitudinals together. So now we have full-length rails that are also boxed-in to the rockers. While installing these, we noticed that the outer ends of our T-bar X-members were a tad corroded, so we availed ourselves of Auto Rust Technician’s cool Safe-T-Cap weld-over repair kit. Our floor pans were also pretty nasty looking, an affliction oh-so common to muscle-era Mopars, so we took the opportunity to install a flawless set of die-stamped pans from Auto Body Specialties in Middlefield, Connecticut. This was really a no-brainer, since, for safety’s sake, we had decided to remove the seats and carpeting before welding in the torque boxes - at that point, the nasty, patched floors were staring us in the face.
The outcome was, to say the least, amazing. The car went from being a typical semi-flexible ‘60s ride to a buttoned-down Benz-like deal. Rattles that had been with us for 20 years disappeared as if by magic, and cornering prowess and steering response, with the suspension pushed to near-limit angles (can you say: spin?) improved drastically and dramatically. And, more importantly, now we’ll have no qualms about punishing the chassis with Barton’s 600-plus foot pounds of pavement-pounding, earth-rotating torque!
Sources cited:
Auto Rust Technicians
275 Niantic Av.
Cranston RI 02907
(401) 944-4444
www.autorust.com
Auto Body Specialties
POB 455
Middlefield CT 06455
(888) 277-1960
www.autobodyspecialt.com
Copyright Mopar Action Magazine, February 2003, used with permission.
In their words,
"This article originally appeared in the February 2003 issue of Mopar Action Magazine. Republished here by permission. This entire work is copyright 2003 by Richard Ehrenberg and Harris Publications, Inc., New York, NY. All rights reserved. Protected under international copyright conventions. This work may not be reposted, retransmitted, printed, published, photocopied, or otherwise distributed, whether by electronic or any other means, without permission in writing from the copyright holders. Violators will be dismembered, marinated, spiced, and fed to hungry lawyers."