QA1 coilovers let you set ride height and tune damping, but the right setup starts with exact vehicle fitment and an honest look at how you drive. Match the parts to the chassis first, then make adjustments one step at a time.
Key Takeaways
| Question | What to know |
|---|---|
| Are QA1 coilovers any good? | QA1's adjustable Pro Coil shocks are dyno tested, serialized and rebuildable. Whether they suit you comes down to fitment, spring rate and how the car is used. |
| How do I choose a coilover kit? | Match the kit to the exact year, model, suspension layout and any changes already made to the vehicle. |
| Front, rear, or full suspension kit? | Pick the axle or system that solves your handling goal, and keep the car's overall balance in mind. |
| How do I set ride height? | Make small, even adjustments, then check shock travel and alignment rather than chasing stance alone. |
| What should I test when tuning? | Start from a baseline, change one damping setting at a time, and record what the car does on the same route or surface. |
| Does my vehicle use a strut layout? | Identify the suspension design before choosing parts. Our strut selection is a useful reference when comparing layouts. |
Start with vehicle fitment and suspension layout
Match a coilover kit to your vehicle's exact year, model and suspension configuration. Similar model names can hide different mounting points, shock lengths or suspension layouts, so confirm the application before comparing adjustment options.
Decide whether you need a front kit, a rear kit or a full system. Existing changes to control arms, mounts, crossmembers or a four-link rear can affect both fitment and geometry, so include those parts in your assessment.
Browse all QA1 Precision Products parts, or narrow it down by type: coil-over shock kits, coilover spring and shock assemblies, struts and rear suspension kits. Use those categories as a starting point, then compare the kit details with the suspension actually on your vehicle.
The catalog shows why the exact application matters. The QA1 RCK52612 rear coilover kit converts a 1963-72 C10 with a coil-spring rear to single-adjustable coilovers with an adjustable panhard bar, and bolts on without pulling the bed. The QA1 GS507-10450C Pro Coil front kit is built for a 1963-82 Corvette with a small block Chevy, using 450 lb/in springs. The QA1 HS01 front strut is a single-adjustable aluminum strut for the 1979-93 Mustang, sold each. Three different chassis, three different parts. Before treating a listing as a match, check the year, engine, suspension layout, current mounts and control arms, and what the kit includes. If your chassis has been modified, confirm compatibility rather than inferring it from the model name.
Shock length matters as much as mounting style. Compare the shock's compressed and extended lengths with the suspension's full movement, not just its position at ride height. Wheel travel and shock travel are not the same: the mounting geometry acts as a lever, and that ratio, called the motion ratio, decides how much shock stroke you use per inch of wheel movement. Confirm nothing binds or contacts other parts through the full range. A shock that fits at ride height can still top or bottom out on the road.
Before installation, inspect mounts, bushings, control arms and suspension joints. Worn parts cause noise and vague handling that new coilovers will not fix.
Choose spring rate for the vehicle and its job
Spring rate is the spring's resistance to compression, measured in pounds per inch. Choose it with vehicle weight, corner weights, motion ratio and intended use in mind, because a rate that works on one chassis can feel very different on another.
Before choosing a rate, weigh each corner with the vehicle in its usual driving condition, including the driver and typical load. Use those corner loads with the motion ratio and the kit's published spring guidance: the rate at the shock is not the effective rate at the wheel. A rate that worked on someone else's car is weak evidence if the weight or geometry differs. Recheck after big changes to the vehicle or its usual load.
For street use, choose enough support for body control while keeping travel and compliance over rough pavement. For drag use, look at whether the spring and shock combination allows the weight transfer the launch needs without topping or bottoming out. For circle track, put repeatable balance ahead of stiffness. Weight, corner loads and motion ratio still decide the actual number.
Treat spring rate and damping as separate decisions: the spring holds the car up, while the shock controls how fast the suspension moves.
The QA1 GS401-10450B GM Pro Coil kit is a good example of how QA1 packages this. It pairs single-adjustable billet aluminum coilovers with 450 lb/in high travel springs, which use fewer coils and a smaller wire diameter for more travel and less unsprung weight. The threaded body sets ride height, the adjuster sets damping, and the kit is sold in pairs. Check the listing's fitment chart for your exact car.
When comparing spring options for the same application, focus on how each rate will support your car. A firmer spring is not automatically better.
Match the setup to street, drag, or circle-track driving
Street driving needs a balance between body control and compliance over uneven pavement. Too much stiffness makes the ride harsher and can cost grip on rough surfaces.
For drag use, consider how the suspension handles weight transfer and keeps the tires planted on launch. Circle-track setups need repeatable handling and adjustments you can make consistently as the track changes through the night.
Change the front, rear or full system with the car's overall balance in mind. If your work is focused at the back of the car, compare our rear suspension kits for your application.
Building your own circle-track coilovers? The QA1 CK5105 coil-over sleeve kit converts one shock to accept a 2.5 in. spring. Depending on the application it includes some or all of an aluminum sleeve, spring cap, spring seat adjuster nut, retainer pin, jam nut and snap rings. It is a single-shock sleeve kit, not a complete suspension package, so compare it with options of the same scope.
Rear suspension choices involve more than the shock and spring. Control links and crossmembers decide how the axle moves. QA1's four-link kits for GM F-body cars, like the R156-170 for 1967-69 (single adjustable) and the R257-170 for 1970-81 (double adjustable), replace the leaf springs with a crossmember, trailing arms, coilovers and 170 lb/in springs.
Set ride height without sacrificing shock travel
Record ride height on level ground, then make small, even changes and measure again. This gives you a clean comparison and keeps the stance even side to side.
At your chosen height, check the compression and extension travel left in the shock. Avoid a setting that leaves it close to either limit in normal driving, because the suspension needs room to move over bumps.
Spring preload and ride height are related but not the same thing. On many threaded-body coilovers, turning the spring seat raises or lowers the car, so follow the kit instructions for how your setup adjusts and measure after every change.
After adjusting height, check alignment and geometry. A ride height change alters wheel angles and component positions, so get it aligned before judging handling or tire wear.
Setup rule: Set the stance you want while keeping the shock travel the suspension needs to work.
Tune shock valving one change at a time
First learn what each adjuster controls. On QA1 single-adjustable shocks, one knob changes compression and rebound together. Double-adjustable shocks give you separate knobs for compression and rebound.
Identify the shock's exact part number before adjusting it, because click ranges vary by model. Use that model's instructions to find its documented range and starting point. Record the baseline before testing; on a double-adjustable shock, log compression and rebound separately. Don't borrow a click count from a different QA1 model.
Change one setting at a time and test on the same route or surface. On the street, look for controlled movement over bumps without a harsh or floaty response.
Keep a written log so you are comparing changes instead of relying on memory:
- Setting: the adjuster position before and after the change.
- Conditions: route, surface and approximate speed.
- Result: how the car responds over bumps, under braking and through a turn.
Stiffer is not always better. Too much damping keeps the suspension from reacting to bumps and can reduce tire contact.
Diagnose bounce, clunks, and installation changes
If the car feels bouncy after installation, work out whether it is too little damping, the wrong spring rate or tire behavior before you adjust anything. Each has a different cause, and valving changes won't fix all of them.
For harsh impacts, topping out or bottoming out, check shock lengths and available travel alongside ride height. Damping can't create travel the suspension doesn't have.
When you hear clunks or bangs, inspect fasteners, mounts, bushings and joints. Coilovers make noise from worn or loose parts easier to hear, so check the surrounding components before blaming the shocks.
After installation or a big height change, check alignment and geometry before judging the handling. That gives you a reliable baseline for tuning.
Inspect and maintain adjustable coilovers over time
Inspect shocks, springs, adjusters, mounts and fasteners regularly for damage, looseness, corrosion or leaks. Catching a problem early stops it from affecting handling or damaging nearby parts.
Keep the threaded body clean so the collars turn freely and the threads don't get damaged during adjustment. After suspension work or a change in load, recheck ride height and alignment and listen for new noises.
QA1's adjustable aluminum shocks are rebuildable through QA1 authorized service centers, so a tired shock doesn't have to mean a new one. When joints in a four-link or control arm setup need attention, our spherical rod ends cover the replacement parts.
Frequently Asked Questions
Are QA1 coilovers suitable for a daily-driven car?
Yes, when the kit fits the vehicle and the spring and damping choices suit street use. Low-profile tires and stiff or worn rubber mounts can still make the cabin feel harsh, even with the coilovers set up well.
Can coilovers be used with factory sway bars?
They can, as long as the installation leaves clearance and the sway bar links work through the full suspension movement. Check for contact at full steering lock and full travel, not only at rest.
Do adjustable coilovers need to be rebuilt?
Not on a fixed schedule. QA1's adjustable aluminum shocks are serviceable and rebuildable, and their condition and QA1's service guidance should decide when that work makes sense.
Can changing wheel or tire size affect coilover tuning?
Yes. A different wheel and tire combination changes unsprung weight, clearance and how bumps reach the suspension. Tune with the combination you actually drive on, and check clearance through steering and suspension travel.
Are QA1 coilovers a good choice for a project car?
They are when QA1 makes a kit for your chassis and you want adjustable ride height and damping. For a car that sees both street and track time, decide which matters most before choosing spring rate and damping.
Who makes the best coilover?
The best coilover is the one built for your exact chassis with a spring rate and damping range that suit how you drive. A well-matched kit from any major brand will beat a mismatched premium one.
Which is better, QA1 or RideTech?
Neither is better across the board. Compare products for the same vehicle and layout: application, what the kit includes, spring options, shock lengths and adjuster type. A complete vehicle kit and a sleeve kit serve different needs, so they are not a like-for-like comparison.
How do you adjust QA1 coilovers?
For ride height, turn the spring seat in small, even steps and confirm the shocks keep enough compression and extension travel, then align the car. For damping, start from a baseline, change one setting at a time and test under the same conditions while logging the results.
Conclusion
Choosing QA1 coilovers comes down to matching the kit to your exact suspension layout, picking a spring rate for the car's weight and job, and keeping shock travel as you set ride height. Tune valving one change at a time, inspect the parts around the coilovers, and keep records so every adjustment moves you toward the ride and handling you want.