2002 Chevy Corvette C5 Z06 Coilover and Sway Bar Install - Confidence Inspiring
Installing LG Motorsports’ GT2 Coilover and G1 Sway Bar Package onto our C5 Z06
From the February, 2011 issue of Chevy High Performance
By Henry De Los Santos
Photography by Henry De Los Santos
It wasn’t long ago that we first introduced our latest canvas, an ’02 C5 Z06 Corvette, dubbed Project Twitch.
If you recall, we invited your thoughts on what direction to take our ride, and the majority of you said to kick it up a notchsome of you even took the time to include detailed wish lists. Well, we heard you and we’ve already produced a complete plan of action; of course, all of it will be covered in the coming months.
This month, we’re addressing the suspension. Bear in mind that the factory offering is pretty incredible; it’s a lot more than most people will ever be able to take full advantage of. We should also mention that if you’re into SCCA class racing, you’ll know that the C5 Zs are extremely competitive cars right out of the box, and altering from the stock stuff will generally place you in a class reserved for serious chassis cars. We have no plans to compete in a specific class; instead, we tend to participate in autocross and open-track events as an exhibition car, so that throws any class-specific rules right out the window.
When it came to finding the ideal suitor for our Z, we went with LG Motorsports (LGM) in Wylie, Texas. The folks at LGM have been in the business of racing and designing hard-core suspension components for well over 35 years and have plenty of real-world track experience by competing in everything from the Corvette Challenge to the World Challenge series to the coveted American Le Mans GT2 division.
After a lengthy conversation discussing our needs and goals, we decided to install a complete LGM suspension package, which includes the GT2 coilovers with 12-way adjustable shocks and the G1 front and rear sway bar assembly. Combined, these offer infinite adjustability, both in ride quality and setting up the ride height for every kind of driving you do. And even though the LGM components may seem exotic, anyone looking to do a similar install will appreciate just how affordable this setup really is. Priced at $2,395 (add $250 for the quiet endlinks), this all-in-one system will transform any C5 into a serious tracking machine, all while offering a plush ride for those long road trip excursions.
To outfit our Z with the LGM goodies, we headed to Motivational Engineering in Carson, California, where owner Mike Saiki handled the job in a day. The installation was straightforward with minimal effort, however, it was Saiki who recommended we complete the install by scaling the car. Even with the good stuff, it takes a well-balanced chassis to keep the tires on the ground and maximize your efforts as you traverse through any course. Follow along as we show you what it takes to transform your prized Z from a weekend thrill ride to a world-class performer.
|Ride Height |
|Front Left ||Front Right |
|275/8 ||271/2 |
|Rear Left ||Rear Right |
|283/8 ||281/2 |
|LG Motorsports Coilovers |
|Front Left ||Front Right |
|265/8 ||269/16 |
|Rear Left ||Rear Right |
|271/2 ||273/8 |
We started by taking off the...
We started by taking off the rear sway bar by removing the four main bolts on the rear carriage with an 18mm socket and a 15mm wrench. For the endlinks, we used a 19mm socket.
Since we’re stepping up to...
Since we’re stepping up to a coilover assembly, the factory leaf springs are no longer necessary and have to be removed. The first thing you want to do is remove the snap ring on the leveling bolt.
Next we placed an adjustable...
Next we placed an adjustable jack underneath the control arm to relieve some pressure for the leveling bolt. Using a 21mm socket, we were able to remove the leveling bolt and did the same for the other side.
From there, remove the four...
From there, remove the four bolts holding the sway bar in place with a 13mm socket and that portion of the job is complete.
Getting the shock out is easy...
Getting the shock out is easy enough. The lower body of the shock mounts onto the lower control arm and can be removed with a 24mm socket and wrench combo. Up top, we used a 13mm socket with a long reach extension to remove the two bolts.
LGM’s 12-way adjustable GT2...
LGM’s 12-way adjustable GT2 coilover assembly may look good, but there’s a lot of engineering that went into these beauties. The lower base or housing should be turned to adjust for ride height, while the perch the springs rest on can be adjusted with the supplied spanner wrench for fine-tuning the ride height. We talked with LGM at great lengths and had the housing adjusted for our application, making it a complete bolt-in assembly that only required minimal adjustments to suit our needs. Aside from the shocks and springs, which are exclusively built for LGM, everything is built in-house using LGM’s knowledge of the Corvette for springs and shock valving.
To attach the rear remote...
To attach the rear remote shock adjusters onto the shock, we used a 5/64 Allen key. Also, you’ll find that LGM uses spherical bearings on all its shock mounting locations (minus the rear lower fork mount) for a precise and smooth operation that won’t interfere with the shock’s functionality. This also eliminates any binding that can occur, preventing the shaft from bending and ultimately providing you with precise movements from the suspension.
To install the coilovers,...
To install the coilovers, we learned that the tie rods needed to be disconnected to give us extra room for fitment. We used a tie-rod puller to eliminate any potential damage. Up top, the two bolts that we torqued to 22 ft-lb went in and we secured the single bolt below through the lower control arm and the lower body of the shock at 162 ft-lb.
As mentioned earlier, the...
As mentioned earlier, the rear remote shock adjusters are tightened onto the shock’s adjustment knob, where it’s then placed through the opening of the upper shock mount. Once on the ground, you can easily reach up to change the shock settings on the fly without a jack.
Every G1 sway bar package...
Every G1 sway bar package comes with the correct diameter bushings in four individual containers. These don’t require any grease whatsoever and can be installed dry, right out of the box.
With the factory sway bar...
With the factory sway bar out of the way, we installed the adjustable G1 piece, which features a robust 11/16-inch diameter. All you need to do is replace the four bolts on the rear carriage, bolt it to LGM’s heavy-duty quiet endlinks, and connect the other side to the lower control arms. Based on LGM’s recommendation, we placed our endlinks (torque to 53 ft-lb) on the middle setting; moving the endlinks to the inside will stiffen the rear bar, whereas placing the endlinks outboard will soften it.
To swap out the front suspension,...
To swap out the front suspension, we began by removing the sway bar. Using a 13mm socket, we removed the four bolts retaining the bushing and the sway bar.
We’ve heard of people removing...
We’ve heard of people removing the washer fluid and coolant tank to gain access to the upper shock bolt. This wasn’t the case for us; instead, we used a 1/4-inch wrench to hold the stud up top and a 15mm wrench to loosen it up.
It took a few steps to remove...
It took a few steps to remove the shock and prepare ourselves for removing the leaf spring. First we placed a jackstand underneath the lower control arm for additional support. Then we carefully loosened the four upper control bolts (watch out for shims and make a mental note of how many there are) and proceeded to remove the shocks.
To remove the leaf spring,...
To remove the leaf spring, we started by taking out the four bolts that hold the unit in place with a 13mm socket.
We know some have been able...
We know some have been able to remove the leaf spring by pulling down on the lower control arms. That just wasn’t enough for ours. We took an extra step and removed the caliper for additional clearance.
With the caliper out of the...
With the caliper out of the way and not getting hung up on the brake line, we gained all the room we needed for the removal. While the leaf spring didn’t come out as easily as we expected, after a little bit of coercing we were able to slide it out through the driver side.
Unique to LGM, the front coilovers...
Unique to LGM, the front coilovers have a broad base shock mount that’s designed to help distribute the load under severe conditions to the strongest portion of the shock tower. Ultimately, this means the coilovers will be able to drive through the worst conditions with little chance of bottoming out—or worse, having to contend with something breaking.
Installing the front coilovers...
Installing the front coilovers is very straightforward. We simply aligned the upper perch into position and placed the supplied bolt loosely up top. From there, we installed the two 6mm Allen bolts into the lower control arm, torqued the upper bolt to 19 ft-lb (21 ft-lb for the lower ones), and finished by mounting the caliper back into place.
The front G1 sway bar install...
The front G1 sway bar install is similar to the rear, and this thing is a monster, measuring in at 19/16 inches in diameter and is a direct replacement for GM’s line of T1 sway bars. Again, torque the endlinks to 53 ft-lb.
It’s worth noting that for...
It’s worth noting that for those of you running aftermarket brake cooling kits, these are designed to clear them with ease.
From the beginning, we scaled our Z to get a better idea of just how it sat from the factory. Truth be told, it was impressive, weighing in at 3,148 pounds with a full tank of fuel and showed our crossweight percentage at 50 percent. Once everything was installed, we weighed the car again, revealing identical 3,148 numbers. We had no idea whether to expect a significant increase or decrease, but we certainly didn’t see that coming. After probing into this, we learned that the GT2 coilover assembly actually removed 13.4 pounds from the chassis; however, the G1 sway bars are slightly heavier over the factory counterpart due to their size, putting us right back to our factory weight. What we did see was a change in the weight distribution, with the rear ending up around 5 pounds lighter, changing the crossweight percentage to 49.3. Our goal was to meet the original 50 percent, only this time with the driver inside. To do this, we disconnected the rear G1 sway bar and ended up altering the ride height slightly from the front passenger side coilover. We’ll have a better idea of how the chassis will react on the road course, but for the time being, this would allow us to compare the results with our original baseline numbers.
LGM uses its experience to...
LGM uses its experience to produce high-quality products that can put you in the winner’s circle—of course, that’s assuming you have the skills to push these components to the limits. If nothing else, the new setup is confidence inspiring under every road condition, and we wouldn’t have it any other way. CHP
The end product was well worth it and certainly validated. For our 420-foot slalom course, we bested our previous numbers by 0.11, running a best of 5.68 at 51 mph over the 5.79 at 49-mph baseline. Keep in mind; we’re going quicker, maneuvering the car through cones all the while gaining speed. On a road course application, and depending on the length of the track, these numbers can quickly add up to secondswhich is huge under competition conditions. The biggest difference was consistency. During previous testing, it would take several laps to procure good numbers, whereas this time, shy of scrubbing the cones, every run besting our previous outing.
When it came to the shock settings, we initially placed them at 6/6, front/rear, but by the end of the day, we set them at 8/7, front/rear, for our final results. Even on the street, these settings seemed to work well for us. Firm? Slightly, but it’s still compliant under rough road conditions and comfortable enough for any road trip. And for those looking for a softer ride, a few turns of the shock settings and you’re good to go; it’s really that easy.
Stock Slalom (On Nitto NT05 tires) 5.89