Front Subframe Installation - Installing a Lightweight Subframe in Our 71 Demon - Car Craft Magazine

How To Install a Front Subframe on a Chrysler A-body

So far, the Dodge Demon project looks much cooler than we imagined. We wanted to capture the feel of Don Schumacher poised on the line at OCIR in 1969 in his record-setting Stardust Funny Car. To do this, we tried to adhere to the ethos even while using available parts that weren't as era-correct as they should be. A glaring example of this is the use of ET Gasser wheels instead of Halibrands or spoked Americans that you'd find in the late '60s, or the Cragar SS/T or Center Lines you'd find on this kind of car throughout the '70s. We're also cheap, so instead of spending the $3,400 market price the era-correct rear 15x10 Halibrand mags command, we found a pair of vintage U.S. Indy mags with the right offset for $60 on Craigslist.

We know it's fun to stare, but we don't do trailer queens at CC. This Dodge Demon needs to be both quick on the street and ultra brutal at the track if we are going to live with it. Like salt sprayed on a prewar jalopy from a lap at Bonneville, the runny shoe-polish dial-ins and car numbers on the flimsy plexiglass will be proudly displayed as we cruise Ruby's in Redondo Beach on Friday nights, hopefully with some flame from the turbos licking the primer off the welds.

That's right, turbo Hemi Dodge Demon. And to get the snake pit under the hood, we decided to go full enchilada and hack the front end off the Dodge Demon, replacing it with a Chris Alston 2x3 A-arm front subframe system. Because that's what Schumacher would do. In addition to a wicked stance, the subframe kills somewhere in the neighborhood of 300 pounds of excess weight and mates to the existing Chassisworks back half and four-link ready and waiting in the rear.

All you need to get this subframe project done yourself is a flat garage floor, a tape measure, a Sawzall, and a MIG welder. Let's go.

NewImage We ordered a 3x2x0.083 boxed frame from Chris Alston, which had a 29-inch width and 6 inches of ground clearance. Using the 29 inches as the base, we added 131⁄4 inches for the suspension and another 4 inches for the wheel offset to get the distance from the outside of the wheel and tire to the lip of the front fender. Ccrp 1107 02+front Subframe Installation We ordered a 3x2x0.083 boxed frame from Chris Alston, which had a 29-inch width and 6 inches of ground clearance. Using the 29 inches as the base, we added 131⁄4 inches for the suspension and another 4 inches for the wheel offset to get the distance from the outside of the wheel and tire to the lip of the front fender. Ccrp 1107 03+front Subframe Installation Before we removed any parts from the car, we made a mark on the door and measured the distance from it to the front wheel spindle centerline. With that number we had the information to position the new frame under the car and retain the stock wheelbase. Ccrp 1107 04+front Subframe Installation Our measurement was 25 inches, which we had wisely written on the door. Using that number, we made a new mark on the floor that represents the spindle centerline. Ccrp 1107 05+front Subframe Installation We also measured off the driver side and connected the dots with a green tape line we used to line up the frame. Ccrp 1107 06+front Subframe Installation The suspension mounts were already welded in place by the guys at Chris Alston. It’s an option we recommend. The frame was long so we could cut it to fit. Ccrp 1107 07+front Subframe Installation We cut a template to cap the hole and provide a place for us to butt the new front subframe. Ccrp 1107 08+front Subframe Installation In this photo you can see both caps and where we intended to weld the new frame along the inside of the old one. Ccrp 1107 10+front Subframe Installation This was the tricky part: Knowing where we were going to butt the frame, we needed to make a new measurement of the distance from the spindle centerline to the face of the plates on the crossmember. Having a tape line in both positions makes this measurement easier. Ccrp 1107 09+front Subframe Installation Measure twice, cut once. Ccrp 1107 11+front Subframe Installation The next measurement is the height of the framerail from the ground. Chassisworks provides a blueprint with each frame, which has this information. We measured from the ground to the bottom of the steering rack mounting bracket and from the top of the frame to the ground and compared the numbers with the blueprint. Ccrp 1107 12+front Subframe Installation110700 DEMN 13jpg1302564693313117 Here, the frame is mocked in position and supported at the correct height. Ccrp 1107 13+front Subframe Installation Before we tacked the frame in place, we mounted the front fenders for one final check. Ccrp 1107 14+front Subframe Installation Here you can see the 4-inch distance from the fender lip to the outside of the wheel and tire. Ccrp 1107 15+front Subframe Installation Using the tape line as a guide, we made sure the wheel sat in the correct position in the wheelwell. Ccrp 1107 16+front Subframe Installation By midnight, we decided to take a break. We ordered the pizza using an iPhone and tracked its progress as it was checked for deliciousness and delivered to the new shop. That is a Boddingtons that Grant Peterson’s drinking. Ccrp 1107 18+front Subframe Installation Back to work, we double-checked to see if the frame was square by measuring diagonally from the frame to the body in several places. Ccrp 1107 17+front Subframe Installation After we were satisfied that the frame height was correct and everything was centered in the car, we tack-welded the frame to the crossmember. Ccrp 1107 19+front Subframe Installation We also welded a connecting plate from the base of the rollcage to the subframe, capping the ends of the framehorns. Ccrp 1107 20+front Subframe Installation This photo illustrates how we connected the subframe to the transmission crossmember. Ccrp 1107 21+front Subframe Installation The final step was to add a plate of steel that tied everything together. Ccrp 1107 22+front Subframe Installation Coming next month: suspension, wheels and tires, and an eBay Hemi. NewImage

Parts DescriptionSourcePNPrice Drag Race A-arm suspension and frame clipChris Alston’s ChassisworksPKG H$1,398.00 Gasser ET wheelsSpeedway Motors91058672$279.00