Hot rodding is a game of compromise when it comes to deciding what your comfort level is in terms of chassis modifications. You could go the bolt-on route, and while it’s easier, quicker, and less expensive, there are certain small compromises you need to accept. The other route involves cutting, welding, and permanently altering your Chevy, but this route—while far more labor intensive—typically results in superior performance.
The latter route was the one we took on our 1967 Nova project with the installation of a Detroit Speed Inc. (DSE) rear chassis and suspension system. The system is composed of three kits designed to work together to maximize performance. The main player is the four-link QUADRALink system, which offers all the benefits of coilover shocks and vastly improved suspension geometry.
Including the DSE mini-tub kit allowed us to stuff massive Falken Azenis RT615K 315/30R18 tires under the back for more grip, and a set of through-the-floor subframe connectors tied the front and rear of the Nova together, providing much-needed chassis stiffness.
The install process involved a lot of cutting, so if you’re not up to using cut-off wheels and doing copious amounts of welding, then you might want to farm this out to a shop. Still, if you take your time and carefully follow the detailed instructions from DSE you’ll save a bit of money and end up with a rock-solid and track-proven rear suspension system under your Chevy.
As we mentioned, the process is fairly involved so we broke down the install into two parts. In the previous installment, Justin Smith and Mike Rossi from Thunder Alley in Mesa, Arizona, knocked out the mini-tubs and started on the floor modifications for the QUADRALink.
In this final installment, Justin and Mike got our Nova ready for the track by finishing up the four-link install and stitching the subframe connectors to the floor. We finished the car off by bolting up the rear brake system featuring Baer 14-inch drilled and slotted rotors and 6P six-piston calipers. We topped the car off with shiny new rollers from American Racing. Their new VF498 wheels in a polished finish (18x10 front, 18x11 rear) offer the car a bit of a modern look while maintaining the car’s old-school vibe.
01. Before the new parts could be stitched in place, Justin got started by removing a few vestigial brackets that were in the way, like this e-brake cable tab. We also drilled out the spot welds and removed the brace in front of the e-brake cable tab.
02. And here’s the area cleaned up and ready to go. Removing the forward bracket left holes in the frame (from the spot welds), so we busted out our Miller 215 MIG/TIG welder and filled them in.
03. With the holes filled in, the areas where we would need to weld the Detroit Speed Inc. (DSE) torque box were ground down to bare metal.
04. After holding the new DSE torque box in place and scribing a line around its edge, Justin made a series of holes in the floor. These will be used later to further weld the torque box to the car.
05. The DSE torque box was then tack-welded in place. All the parts were tacked in until the project was finished. That way if we needed to make an adjustment it would be easy to reposition a component. In the end it was all fully perimeter welded.
06. Remember the holes we put in the floor? Well, now was the time to move to the interior and do a bit more welding.
07. These preformed and ready-to-rock brackets from DSE are for attaching the long, lower links to the bottom of the Nova.
08. Using the measuring instructions from DSE, we located where the link brackets would mount under the Nova. They ended up bridging the seam between the factory framerail and the new torque box. A bolt through the bracket and the factory leaf spring bracket helps to locate and secure the bracket. The same was then done on the passenger side of the Nova.
09. The DSE Swivel Links are pretty cool assemblies. The big benefit is they don’t bind and aren’t noisy like Heim joints. The system also incorporates longer (than those typically found in four-link systems) upper arms for better pinion angle control, and it has improved antisquat geometry. The lower links are offset inboard for even more tire clearance.
10. The longer, lower links were then bolted to the forward link brackets as shown.
11. The upper links were bolted to the tabs on the large floor plate we installed in the first part of this story. With that done, all four links were in place and ready for the rearend.
12. DSE has quite a few shock options based on the driving plan for your car. We opted for their JRi/DSE-valved billet shock system. After doing some math, we went with 11-inch, 175lb coil springs.
13. On the driver’s side, the bracket to the rear of where the top of the shock assembly bolts up provides a point on the chassis to mount the adjustable Panhard rod. Again, everything was tack-welded for now.
14. This is where a lift and a transmission jack would have really been handy, but we made due with our Harbor Freight floor jack. In our case, the brackets came installed on our new Strange Engineering rearend housing but they weren’t welded in place and spun on the axletubes. This meant we needed to use the jack to position the rearend precisely under the Nova at about the right pinion angle so we could tack the brackets to the rearend housing. In hindsight, we should have just had DSE weld these brackets in place for us to save the extra work.
15. When everything was perfect, we busted out the Miller 215 and MIG-welded everything in place on the driver-side of the housing.
16. The same was then done on the passenger-side. It’s critical that everything be square and all the angles perfect before doing this, so measure, remeasure, and measure one more time.
17. The last bracket we put in place was the large one that provided a mounting spot on the rearend housing for the Panhard rod. Once squared up, it was tacked in place.
18. With the QUADRALink tacked in place, we moved on to the DSE subframe connectors. They will tie the front of the Nova to the rear framerails of the car, and since they pass through the floor, they provide even more chassis stiffening.
19. Included in the DSE subframe connector kit are the brackets for mounting to the front frame of the Nova.
20. Using the supplied template, we marked where the subframe connectors would pass through the floor and made the necessary cuts. We advise that you cut small and work your way up until the connectors fit snuggly through the floor. This will make welding them in easier and they’ll also look better when done.
21. Here you can see how the DSE brace passes through the floor of the Nova. The process was: test-fit, trim, test-fit, and repeat until perfect.
22. Using a pole jack, we held the front in place so we could mark where the brackets would meet the bottom of the Nova.
23. With the brackets located, we removed the connectors from the Nova and welded the brackets to the subframe connectors.
24. Before putting the subframe connector assemblies back under the Nova, we made sure to grind off the old undercoating so we could weld. The tab with the four slots is for mounting the DSE transmission crossmember. Once clamped in place, we fully welded the brace to the floor.
25. We then went to the rear and welded the subframe connector to the floorpan. We then welded the end of the subframe connector to where it butted up against the DSE torque box installed earlier. This step is crucial since it’s what ties the entire system together for maximum strength.
26. Here’s the installed subframe connector fully perimeter welded, seam-sealed, and given a coating of paint.
27. To finish off our install, we slid the Strange 31-spline axles into the tubes and began installing our rear Baer brake kit, starting with the parking brake pads and radial caliper mounting brackets.
28. A pair of 14-inch rotors and some beautiful silver Baer 6P rotors finished off the install.
29. We finished off the look of our Nova with a set of American Racing VF498 wheels with a polished finish (18x10 front, 18x11 rear).
30. And here’s our DSE QUADRALink system fully welded in place, seam-sealed, painted, and ready for the track. You can also see the adjustable Panhard rod and DSE sway bar system installed. Installation of the kit is somewhat involved, but once we got the Nova on the track, all the extra effort paid off with a huge improvement in handling. And given how grippy our new Falken Azenis RT615K 315/30R18 tires were, the extra chassis stiffness was a big help.
To get some baseline performance numbers on the Nova, we headed out to Fontana and put our test driver, TEN Tech Center Manager Jason Scudellari, behind the wheel to navigate our 420-foot slalom course (six gates, cones 70-feet apart) in the parking lot of Auto Club Speedway. As we suspected, hitting the course in pre-suspension upgrade form and on less-than-stellar tires, the car was quite a handful as Jason was only able to squeeze the car through the cones in 7.14 seconds, which translates to an average speed of 40.3 mph.
We also did some before and after 60-0 brake testing with the car to record the improvement from the existing front disc and rear drum brakes that were on the car when we started.
As expected, the car lacked the braking prowess we’ve become accustomed to in our upgraded classic muscle cars. Needless to say, it was quite challenging to get the car to stop smooth and straight. With Jason attempting to modulate the brakes during braking, it was difficult to get the car to slow down without having one of the wheels locking up throughout the process. On the first attempt it took 200.4 feet to get the car to stop from 60 mph. Not good. Each subsequent attempt got worse as more heat got into the pads and in the brake fluid.
“Before” testing through the slalom shows excessive body roll, which translates to a sloppy driving experience. The front tires look as though they want nothing to do with this kind of aggressive lateral movement.
With the full Detroit Speed suspension system bolted in (front subframe, QUADRALink rear, and subframe connectors), complete with JRi shocks and Strange rearend, we were ready to hit the track, but not before we strapped on our larger Falken rubber (275/35R18 front, 315/30R18 rear). As expected, the car improved greatly through the slalom by rewarding us with a 5.95-second average time through the cones, which translates to 48.5 mph. That’s a 1.19-second and 8.2-mph improvement from our baseline numbers.
We continued testing and moved on to get final braking numbers with the Baer 14-inch rotors and six-piston calipers. It was no surprise that the numbers were way better, and with a best 60-0 stopping distance of 118 feet, we shaved 82 valuable feet off our stopping distance. That’s a huge improvement when you relate it to having to come to a quick stop on the highway or when you want to dive deeper into the corners on a track day. Not only did the braking distance-wise improve, but the repeatability without brake fade was a massive bonus. Keep in mind, being able to stop quickly is an important factor when it comes to safety, and being able to repeat the process numerous times without experiencing brake fade will keep you out on the track longer, as well.
Although we did not perform before and after drag testing, we have to report that the Strange rearend armed with 3.73 gears gets the Nova off the line much quicker and we now have absolute confidence this rearend will hold up to tons of abuse and just about anything we throw at it power-wise.
While the focus was on performance testing with the Nova, we would be remiss if we didn’t report on how the car’s driveability improved on the street as well. The car no longer feels sketchy driving down the highway at speed and we gained tons of confidence in traffic. The DSE rack-and-pinion steering is not too quick for the street, yet performs as expected on the track. The car is now a blast to drive and we are able to take corners more aggressively, like we would in a late-model car. Overall, our ’67 Nova is much more fun to drive … on the street and at the track. After all, driving a muscle car that can actually flex some muscle is what this hobby is all about.
“After” testing shows the car has much less body roll and is able to attack the slalom at a much faster pace than before. The Falken tires are right at home in this environment and provide plenty of grip. All of this translates to a much better driving experience.
Here you can see the car before we installed the Detroit Speed Inc. suspension. It’s got an old-school muscle car rake, but not much there will help it perform on the street or track.
With the new suspension, wheels, and tires, the car has a more aggressive look and a lower stance—all the things necessary for a more fun driving experience. And since this photo was taken, we’ve addressed the low-slung headers with a new set from Doug’s Headers that tuck up tighter to the chassis.