Our project ’98 Mustang already benefits from a host of modifications, including a complete PI engine swap. With only lowering springs and take-off shocks and struts, we thought it would be a good idea to upgrade the front suspension system. We turned to Team Z Motorsports, a leader for high performance light weight suspension components for one of their new auto cross K-member and A-arm packages. We also went to QA1 long known for their innovations in adjustable front suspension technology for our adjustable struts, springs and coil overs.
Stronger, Lighter, Faster
Through our involvement with the Cobra Jet program I had the opportunity to get input from engineers at Ford Racing on designing a road race oriented K-member. -Dave Zimmerman, Team Z Motorsports
The factory K-member is not necessarily designed with ultimate performance in mind. While it does a good job of holding the engine and front suspension together, it also leaves a lot to be desired in terms of access for working on the car. Plus it’s heavy; the stamped-steel stocker tips the scales at over 80 pounds with the front control arms!
Having worked for years on drag racing oriented suspension types, Team Z owner Dave Zimmerman made the decision to get into the road racing K-member market, “Through our involvement with the Cobra Jet program I had the opportunity to get input from engineers at Ford Racing on designing a road race oriented K-member.”
The Team Z K-member is lighter and stronger than the factory original piece. Constructed from 1.50-inch diameter 0.120-inch wall DOM steel tubing, it offers increased front end stiffness and strength. The auto cross kit, part number TZM-AC, which we’re installing on our ’98 GT also adds extra gusseting to the engine mounts and extra thick control arm tabs. The side braces for the K-member are also triangulated. These features give the front suspension additional strength and rigidity.
The Auto Cross kit comes with Team Z’s Auto Cross front A-arms. The A-arms are made from 1.125-inch 0.95-inch wall 4130 chrome-moly steel. They are double gusseted for improved strength and feature heavy duty bushings with 4130 inner sleeves. The bushings are a derivative of the ones Team Z uses in their Street Beast line of rear control arms. “That bushing is very stiff, and will give minimal deflection,” says Zimmerman. All of the welds on the control arms are TIG welded.
Converting to Coil Over
You can adjust the strut as the horsepower and output of your car changes. -Dave Goldie, QA1
For our strut and spring upgrade we’re using QA1 struts, coil over sleeves, springs, and caster-camber plates. This not only offers us a weight reduction, but allows us a broad range of adjustability on our struts. A coil over kit is required when using Team Z’s parts as the factory spring pockets are eliminated on the tubular counterparts.
Our struts are part number HD603S, they feature a steel body, with a twin tube design. Dave Goldie from QA1 tells us, “You can adjust the strut as the horsepower and output of your car changes.” This means as we increase the power output of our project car, we can adjust the front suspension accordingly, or even if our driving styles between road racing and drag racing change. The struts like everything else that QA1 offers are also rebuildable, if one isn’t performing properly, or if we know they’re worn we can remove them and send them to QA1 for servicing.
Adjusting The Struts
Our double adjustable struts feature 18 settings for both compression and rebound. They can be adjusted for anything from comfortable cruising, to maximum weight transfer in drag racing, to corner slaying tight. The total number of possible permutations of these is 324 unique settings. This means that we can, with certainty, adjust the front suspension to our exact needs or taste with the simple turn of the dials.
Our struts were already setup to accept the company’s coil over kit, part number COK103 which was easy to install and offers incredibly fine adjustment for ride height.
The caster/camber plates, part number CC104MU, are made from high quality steel. Caster/camber plates are necessary to handle the change in load to the strut mounting point, which will now also bear the front end weight of the car. They’re also needed to get the front end aligned properly, which has limited adjustment with the factory parts. The spherical bearing design means there is no rubber bushing to deflect the front struts, further cementing the car’s handling.
Just like our new struts the caster/camber plates can also be rebuilt. QA1 is a large supplier of spherical bearings to the aftermarket. “The bearing in our caster/camber plate is a large proprietary design, no one else on the market offers it,” says Goldie. Should that bearing show signs of wear, we can remove and replace it alone, effectively rebuilding the plate without the need to completely replace it.
This installation was performed using a drive-on lift. This particular lift gets the car in the air high enough that you can easily sit under it to work, but the chassis must be supported by jack stands. Choosing to leave the engine in the car required the use of an engine support beam to hold the engine in place while the original K-member was removed. We spent the first few hours removing the stock components, and K-member followed by quickly getting the new Team Z K-member into place.
“We try to pride ourselves as the no fuss and no grind manufacturer,” says Zimmerman. Our K-member was the first of it’s kind for an SN95 from Team Z, so being an R&D part, we expected a little more work. After adjusting the motor mounts for a few minutes to get the new K-member in, we were impressed with how well the new piece fit.
The Team Z K-member is designed for use with aftermarket steering shafts and racks. As a result of this we had to grind some material away on the rear gusset on the driver’s side motor mount to clear our factory pinch bolt. We could have used an offset rack bushing to move the rack down a bit more – this may have done the job in clearing the factory rack. Zimmerman assures us he’ll be getting his hands on a stock steering shaft to clearance all future k-members.
The entire installation for one person – working alone, with hand tools and an electric impact gun – took a full day. Fortunately the garage we used for this install is just a half mile from a local alignment shop that’s familiar with caster/camber kits and coil overs. They were able to equalize our ride height, which dropped 3/4 of an inch after the installation of everything.
This ride height change tucks the front wheels a little more but still gives us decent ground clearance. It also sets the front control arms nearly level. Having the control arms nearly level gives the car the best possible alignment, and allows for the more tire contact patch to remain on the ground under hard cornering.
Caster and camber were set to stock specifications, and the tech performing the job sang the praises of all the parts stating that he was impressed with how easy it was to align the car, and how well everything appeared to fit.
We were not able to get the steering wheel back to OE-straight though. This is because the Team Z K-member is designed for use with wide variety aftermarket rack and pinion options, and the factory rack is keyed to the shaft. Team Z actually offsets the rack 3/8-inch to the right. OEM-style tie rod ends also don’t allow enough adjustment to compensate as they don’t have the necessary thread. To fix this we need to install a bump steer kit, something we should have thought of when planning our swap. We’ll live with this until our bump steer kit comes in a few weeks from now.
We were impressed from the start with how well the car drives, even without having the new sway bar links when we went to the alignment shop. The car felt tighter without them than it did with them on in factory form that we’d been using for the last 100,000 miles.
With everything in place we took the car out for a test drive and put it through some of the tightest corners we could find. It’s still winter at this car’s home location, so no tracks or auto cross clubs were open when we did our testing. We can tell you that the difference in front end stiffness is phenomenal. There is much better steering feel, and the cornering bite is confidence inspiring. We haven’t touched the adjustments on our QA1 struts yet, we found that set dead in the middle as they were from the factory they provide a great combination of smooth, sporty ride, crisp handling, and good ride compliance.
We actually think the car does better over pot holes, seams, and rough pavement. With less weight in the front end the suspension can react faster to changes in road conditions. This entire swap even fixed a wobble issue we’d been fighting for years; at around 45 mph we’d had a shake in the steering wheel that we’d been unable to diagnose. We’d suspected that something in the front end was worn but had never located the failed part. That shake is gone, replaced with better road feel.
With adjustable suspension on board we’re now anxious to get out to both an auto cross and the drag strip. We’d like to loosen up the front end to see how the car launches and if we can improve our ET’s. At the same time we’d also like to leave all the settings the same and take it through the cones. We’re extremely pleased with the way this upgrade turned out and can’t wait to turn the car loose on the track.
- TZM-AC Team Z Auto Cross K-member kit
- HD603S QA1 Double Adjustable Front Strut
- 14-250 QA1 14 inch 250 lbs Spring
- COK103 QA1 Coil over sleeve kit for steel struts
- CC104MU QA1 Caster/camber plate kit.