Coil Over

Need to improve the cornering and handling on your Chevy Camaro? Tire Rack has a number of solutions in our performance suspension product lines. Ranging from complete systems (springs, bars and dampers), or single components you can lower and firm up the suspension to dramatically improve cornering and handling while also improving the stance of the car. 

Tire Rack did some testing in various configurations. Starting with a spring swap, we found an increase in handling with a mild firming up of the ride. A very nice modification but still quite tame. From there we went to a complete upgrade in springs, dampers and roll bars. This improved all areas of ride control and responsiveness, making us wonder why original factory set-up wasn't like this. We also tested a coil-over system for those wanting complete control of the set-up. Read Suspension Component Test Results.

Options are available for model years 2010 and 2011 in most engine and trim levels.

Shop by vehicle to see which suspension products are best for your vehicle. 

Tire Rack driver Chris Harvey pointed the Project STR Mazda MX5 550 miles south to Blytheville, Arkansas for our first SCCA ProSolo event of 2011. Co-driver John Rogers was tending to One Lap of America event duties so Chris was on his own to dial in the car and take on the solid, 12 car STR class field.

The Friday test and tune course was put to good use as adjustments were made for the unique and tricky concrete surface. Using our tried and true Dunlop Direzza Z1 Star Spec tires, KW Variant 3 coil-overs and Hotchkis anti-roll bars, the set-up was tweaked to remove some persistent oversteer we encountered. Nice gains were made on the clock and confidence was high going into Saturday’s first heat competition.

Long time SCCA National level Solo driver Darrin Disimo put down the fastest right side time while Chris followed-up with the quickest left side time during first heat competition runs on Saturday morning. Darrin’s co-driver and car owner, Dave Marcus showed flashes of speed on par with the front runners, but cone troubles pushed him back in the running order.

An announcement was made by event officials after the first heat that all three heats would be run on Saturday due to the strong possibility of rain during the normal Sunday morning final heat. That’s all the inspiration the STR drivers needed to push extra hard in the second heat in search of every bit of time they could find on course. Darrin came out swinging, putting down the quickest clean right side run but ran into cone troubles on the left. Chris answered with a half second improvement on the right side but then ran into red light troubles on his final two runs of the heat to nix any further gains. Once the math was done, Darrin held onto a solid .658 second lead, as the drivers headed into the third and final heat of the event. Dave Marcus cleaned up his first heat cone troubles to move into third, just four-tenths off Chris’ pace.

Tensions were high and some class leading competitors were observed doing rain dances as the final heat runs began late Saturday afternoon. Lots of bandwidth was being used as competitors kept one eye on the sky and another on the weather radar as rain clouds were building to the west. The course remained dry and fast until the STR competitors were directed to the starting line. The skies were dark as the ProSolo starting lights came down on the class leaders. With the wipers coming on and lightning in the distance as they rounded the half way point, Chris and Darrin charged through the finish each finding time on course and Chris closing the overall gap by two-tenths. The drivers then switched sides only to find the lightning closing in and the sprinkles turning into a steady drizzle. Once the drivers launched onto the course, it was clear the concrete had lost some grip and no additional gains would be found. As Darrin and Chris crossed the finish line for a second time, Darrin claimed the event win as the skies fully opened and soaked the course to prevent hope of improvement for the remaining two runs. 

The weather at the Tire Rack headquarters in South Bend, Indiana is finally turning as we head into May, this will allow for additional tire testing and suspension work as our search for additional speed continues. Our sights are set on the next major event for Project MX5, the 2011 Tire Rack SCCA ProSolo and National Tour in Lincoln, Nebraska over Memorial Day weekend. Chris and John can’t wait to have another crack at the ProSolo Finale and National Championship event site.

I recently installed a great set of coil-over shock and springs in an effort to improve handling and my car's look. While the decrease in gap from the top of the tire to the bottom of the fender lip looked great, I found after inspection that my rear tires were very close to rubbing the fender lip in the back.

What to do? ROLL THAT FENDER !

Tire Rack sells a great tool that when used with an industrial heat gun (and patience), got me out of the jam I was in.

The fender lip rolling tool features an adjustable arm and a non marring roller that will slowly bend the fender lip up and out of the way for additional clearance. It is essential to use a heat gun to keep the paint flexible enough to avoid cracking as the metal is worked.  

You can see detailed instructions on the tool in the User's Guide. (PDF)

If you've recently installed bigger wheels and tires, or lowered your car like I did then you may want to consider picking this tool up!

Looking to take your performance vehicle to the next level on the track or at the next autocross event? Designed with the enthusiast in mind, Hotchkis Sport Suspension Competition Anti-Roll Bars improve handling and reduce body roll via a more aggressive rear bar set.

One advantage of running a thicker rear bar vs. stock is added over-steer, which maximizes the vehicle's race tires for on-track performance. The Hotchkis bars can also be used if your vehicle currently has lowering springs or a coil-over kit.

Popular Applications for the Sport Anti-Roll Bars

Model	Year	Front Diameter	Rear Diameter
Chevrolet Camaro	10+	32mm, 1 Position	25mm, 3 Positions
Nissan 370Z	09+	35mm, 1 Position	27mm, 3 Positions
Infiniti G35	08+	35MM, 1 Position	27mm, 3 Positions

Start shopping by vehicle, brands or product categories from our Suspension page to see which suspension products work best for your vehicle.

Additional information:

"Understanding Basic Suspension Terminology"

The KW Clubsport Coil-Over is for customers who demand a better handling car during track day events, but also want a setup that can be used for every day driving. The set up ensures excellent handling, performance, agility and faster lap times.

Key Benefits & Features of the KW Clubsport Coil Over:

•    Height adjustable
•    Performance setup for the track
•    Linear, high performance race springs
•    Stainless steel “inox-line” damper bodies
•    Independently adjustable, low speed, compression/rebound forces

The suspension setting is adjustable to meet the requirements of your tires and the intended use of your vehicle based on the vehicle load and to better match your driving style.

For more information on improving your vehicle’s performance, read:

“Altitude and Attitude Adjustment”

Shop by vehicle to see which suspension components work best for your vehicle.

A complete coil over system is one solution to improve your vehicle’s performance.

The system combines springs, shocks and bump stop into one assembly. The coil-over set-up is similar to a race set-up in that it allows tuning of the vehicle through ride height adjustment. Coil overs often use an adjustable spring perch that allows for different vehicle ride heights without changing the springs.

Springs encompass the shock and bump stop, working to minimize bounce that occurs during driving. Shocks help control suspension movement while bump stops keep your vehicle suspension parts from coming in contact with the vehicle’s frame.

More information on suspension terminology can be found here:

“Understanding Basic Suspension Terminology” 

H&R Springs has one simple philosophy: “Build the best and the rest will follow.”

Whether it’s the Premium Performance Coil Over Kit or one of their Sport Springs Sets, H&R’s products are tested and approved by the German government’s TUV agency for quality, safety and reliability. All springs developed by H&R are precision-wound with the highest quality German spring steel available.

Engineers who develop racing suspensions also design the RSS Club Sport Coil Over Suspension Kits. These kits enhance the performance and corner-handling ability of your vehicle without harshness.

Shop by vehicle to see which suspension component works best for your vehicle.

Looking to upgrade more than the wheels on your Mini? Upgrading the suspension will properly lower your vehicle while offering an improved ride, handling and performance.

The ST Coil-Over kit for the Hardtop Mini Cooper is a Premium and Performance Street suspension product that provides great performance at a great value. Designed and manufactured alongside KW's (ST Suspension parent company) products in Germany, the ST coil-over is engineered after the KW Variant 1 Coil-Overs.

Heavily galvanized for exceptional rust protection, the ST Coil-Overs are backed by a five-year limited warranty.

Shop by vehicle to see which suspension products work best for your vehicle.

Are you looking to improve the suspension on your vehicle? With options available from companies such as H&R, Eibach and Koni, Tire Rack has the products to improve your vehicle's appearance and handling.  

An entry-level introduction to improving your vehicle's appearance and handling is to purchase a set of lowering springs and performance dampers.

If you are looking for more control over adjustability then consider a coil-over or cup kit. 

Anti-roll bars are also a great addition to improve handling and help remove body roll around corners. 

Lowering will change the ride characteristics of the vehicle, therefore give some thought to the balance you want to maintain between handling, looks and ride comfort. If you have upgraded your wheels and tires to a larger-than-original size, you will also want to check clearance before you decide on the kit you want.          

Are you looking to shave time of your laps at the track? One way to do this is to improve the handling of your Porsche 911. By upgrading your OE suspension, you can hit that apex faster and with more confidence.

One of the best ways to improve your suspension is to upgrade to a coil-over damper system.

Coil-over systems from Bilstein, KW, and H&R give you the performance needed to shave off valuable seconds at the track and the flexibility to fine-tune both the ride height and damping rates to dial-in your Porsche 911 to fit your specific driving style.

Thinking about a suspension lift for your truck, but you don't want an overly stiff ride?

Consider the Traxda Lift and Level Kits.


Traxda kits lift your ride by relocating the mounting point of the spring that holds the truck up without changing the location of the stock suspension arms. Installation is simple and does not require the removal of all suspension components like many kits. Because spring pressure is not increased, it doesn't compromise the stock ride.
 
Each Traxda kit is fine-tuned to your vehicle to ensure stock compatibility and quality. 

With a coil-over style suspension, the strut length is extended while retaining the stock spring pressure. This keeps the smooth ride of a stock truck, with no increase in harshness. For a torsion bar style suspension, a re-indexed torsion key and shock relocator brackets are included to change the location of the torsion spring mount without changing the spring tension. 

All Traxda kits come complete with hardware, full instructions, alignment specs and dedicated technical support. Most kits are a direct bolt-in style, simple and easy to install with nothing more than common hand tools and require no modifications to your vehicle.

Coil-Over: an automotive suspension device which refers to a spring or "coil" mounted over the damper (shock or strut).

There are advantages to the coil-over versus a conventional spring and damper system that include ease of installation and simplified height and stiffness adjustment. Many coil-overs offer easy fine-tuning that's not available from conventional suspension systems.

Coil-Over Kits are available for many German vehicles such as Porsche, BMW, Audi, and Mercedes-Benz. There are also many domestic and Japanese fitments for cars such as Corvette, Mazda Miata and RX7, Nissan GT-R, 350/370Z, and many others.

It’s been a busy two weeks for Project STR.

Our first outing took us to Miller Park in Milwaukee, WI for the CENDIV Divisional Championship. This area has been a hotbed for street tire competition with plenty of fast drivers to help us gauge our performance. GRM/Tire Rack drivers Chris Harvey and John Rogers traded fast times both days. Chris pulled out the win with really quick times on his fourth and fifth runs.

Fast forward one week to the Great Lakes Divisional Championship in Peru, IN. This site is the best simulation of the Nationals course surface we can find east of the Mississippi. The battle was tight all weekend, with Chris Harvey out in front after day one by just 0.060 seconds. The course on day two was fast and hard to visualize in a few spots, but that didn’t slow down team STR. John Rogers threw down a crushing second run that no one could match, but it wasn’t enough to make up for his deficit from day one. Chris Harvey was second-quick for the day just 0.4 second back with autocross legend Jim McKamey less than a tenth behind.
Nick Jackson experimented with a wing on his S2000, and ultimately went faster without it. After two days, the three trophy spots were covered by a scant 0.078 second, with Chris Harvey, Nick Jackson and John Rogers finishing first through third respectively. Tire Rack driver Angie Rogers also got her first taste of the MX-5 this season, winning the STR Ladies championship and getting primed for Nationals next month.

If the competition at the Tire Rack SCCA Pro Solo Finale and Solo National Championship in Lincoln, NE next month is this tight, it’s going to be a heck of a battle to see what driver/car/tire combination comes out on top. We think we’re ready for the challenge.

Our efforts to fine-tune the suspension set-up on Project STR are paying off, as shown by our recent success in competition. A close look during maximum cornering shows just how well the KW Coil-Overs and Hotchkis Anti-Roll Bars maximize the footprint and cornering power of the Dunlop Direzza Sport Z1 Star Spec tires on our MX-5.

The blog has been a little quiet while we were hard at work installing and testing “go-fast parts” on the Project STR MX-5. In addition to the KW Variant 3 Coil-Overs and Hotchkis Sport Anti-Roll Bars, we’ve been experimenting with different sizes of Dunlop Direzza Sport Z1 Star Spec tires to find out what makes our MX-5 faster. A full tire test report will be appearing in the next issue of Grassroots Motorsports magazine on newsstands in a few weeks.

To put our efforts to the test, we competed in the Tire Rack SCCA National Tour autocross in Peru, Indiana. 15 drivers showed up in an array of vehicles – Honda S2000s, Pontiac Solstice, BMW Z3 and our Mazda MX-5. Day One saw Mike Lillejord jump out to a half-second lead in his Pontiac Solstice over Matt Glagola in his S2000. Our MX-5 was less than 2/10ths further back with Chris Harvey at the wheel, while John Rogers was just another 1/10th of a second behind in 4th place.

Sunday dawned a new day with a revised course layout that featured a six-cone slalom and several fast, decreasing radius turns. Chris and John changed tire pressure and shock settings to help the MX-5 put down more power when driving off the corners. Our drivers used this to their advantage, posting the two quickest times of the day in the STR class. When the dust settled, the margin Mike and Matt gained on Day One was too much for our MX-5 to overcome, leaving Chris and John in 3rd and 4th respectively, about 0.4 seconds behind the winner.

As a reference point for how the project is progressing, this weekend 2nd place finisher Matt Glagola was driving the Honda S2000 that won the Dixie Tour earlier in the year where we were over eight seconds behind in our bone-stock MX-5. At least on this day, on this course, we’ve closed the gap to his car down to a scant 0.015 second margin. We still need to figure out how to chase down Mike and his Solstice. I guess we have a little more work to do.

<Click on the photo for a video of Chris Harvey's FTD run>

See a tire or wheel package you would like to put on your truck or SUV but you do not have enough clearance for them to fit properly? Superlift and Traxda makes suspension lift kit or sometime it's called a leveling kit that will give you a little more clearance that you are looking for. These kits are designed to lift the front suspension to level the vehicle. On most trucks or SUV the clearance problem is the front, the rear usually have plenty of clearance. The kits work with factory suspension components to achieve modest ride height gains. Installation is straight forward and normally inexpensive. If you only need 1"-3' of clearance these kit will do the job. The Superlift and Traxda lift systems utilize one of three methods to achieve increased ride height depending on the vehicle’s suspension design. With the Coil Spacers system it allowed me to be able to put 33" tires on my Toyota 4Runner and I was able to install the kit in my own garage. Note that some special tools are required and this should only be attempted by a qualified person with experience.

 

 

Strut Extension - Most late-model 1/2-ton trucks and SUVs utilize a coilover strut for the front suspension; the shock and coil spring are together in one compact unit. A simple strut extension is utilized on these applications. This involves adding an application-specific spacer to the top of the factory strut assembly. This method does not preload the factory coil spring (which would degrade ride quality) or over-extend the factory shock. No modifications to factory-installed parts are required and no time-consuming dis-assembly of the factory strut is needed. The strut extension is easily removable should the vehicle need to be returned to stock, and some applications include modified extension stops if needed. Level-It strut extensions are the most cost-effective and efficient way to level the stance of your late-model truck.

  

 

 

STRUT EXTENSION FEATURES

Mounts on top of the factory strut assembly Allows the use of plus-size wheels / tires Easy installation and removal – no strut dis-assembly required Ideal for restoring height lost from heavy front bumper / winch combos Enhances appearance by leveling the stance of the vehicle 10.9 grade metric hardware included Limited Lifetime Warranty

   

Torsion Keys - Vehicles equipped with torsion bars have a certain amount of adjustment built into the factory system. This suspension height adjustment takes place via a bolt that indexes on a torsion key attached to each torsion bar. Simply “cranking up” the factory system is not the right way to go about gaining minor amounts of lift due to a number of factors. Level-It torsion keys are direct replacements for the factory pieces but feature different torsion bar indexing. The forged-steel keys are 25% stronger than the cast factory pieces, and when necessary new metric hardware is supplied to prevent “over-cranking” the bars. Shock extension and mounting tool adapters are also included with some applications.

  

TORSION KEY FEATURES

Heavy-duty forged steel construction is 25% stronger than OEM keys Provided 1.5” to 2.5” of adjustable lift height Designed to grab the “flat” of the torsion bar for a tighter fit High-gloss powder coated finish Shock extensions included with some applications 10.9 grade metric hardware included Limited Lifetime Warranty

 
 

 

Coil Spring Spacers / Block Kits - Applications that utilize a coil spring front suspension utilize a coil-spring spacer to achieve lift. In most 4WD applications, this spacer is constructed from laser-cut steel and mounts on top of the factory coil. Most 2WD vehicles utilize a steel-encased urethane spacer that will not deteriorate or decrease ride height over time. Both designs ensure silent operation as the suspension cycles. When necessary, shock extensions are also included. With some of the taller lift heights (3" to 3-1/2"), the amount of lift exceeds the factory rake. This results in a slightly rear-low stance that is popular in some areas. However, for those that want to maintain a level stance, or the traditional rear-high stance, a variety of different block kits are available to suit every taste or preference. All block kits are sold separately.

  

 

COIL SPACER / BLOCK KIT FEATURES

Steel-encased urethane spacer construction will not deteriorate or decrease ride height over time Urethane provides a smooth and quiet ride Some spacer kits include shock extensions Lift blocks include OEM features for proper spring pad engagement and bump stop function Block kits include U-bolts and hardware Limited Lifetime Warranty

   

Since the beginning we have noticed significant lateral body roll in the Project STR MX-5. Installing the KW Variant 3 Coil-Overs with the stiffer spring rates improved it marginally, but we feel it still needs to be reduced further. Past test experience has shown us that tuning the anti-roll bars can have a significant positive impact on responsiveness and cornering power.

So, the next logical step in our build-up was to install a set of Hotchkis Anti-Roll Bars. For this application, the tubular bars are larger diameter than the O.E. bars. They're also 3-way adjustable front and rear, which should help us tune the balance of the car to our liking, and to work well with the rest of the suspension and wheel and tire upgrades we’ve already made.

We had a chance to test drive our BMW 325i test cars with both lowering springs and coilover shock/springs installed and what an experience!

The cars outfitted with the O.E. shocks/struts and the Eibach Pro-Kit Springs ("mild" lowering, about one inch of drop) felt nearly as comfortable as stock, but helped the car feel more responsive to steering input. 

The Eibach Pro-System Plus Kit "sport" springs lowered the car nearly two inches and made a noticeable change in both handling and ride comfort. It was nothing that I felt was too stiff for daily use.

The Eibach Multi-Pro Coil-Over R1 Kit was set up to lower the car about two inches as well, but the more aggressive shocks made a pronounced change and took a fair amount of comfort out of the ride on city streets and highway runs. 

While the coil-over gives you the flexibilty to adjust your ride height to make it "just right," it will come at the cost of some ride comfort. I'd say that coil-overs are best on a track car in my opinion!

A coil over is created when you combine a spring, shock and bump stop into one unit. The spring itself encompasses the shock and the bump stop, and works to minimize any bounce that occurs when the vehicle comes in contact with road imperfections. And while the shock helps control unwanted suspension movement, the bump stop keeps all of your vehicle suspension parts from coming in contact with the vehicle's frame. In addition, coil overs are usually on an adjustable spring perch so that a vehicle's height can be adjusted without having to change the springs themselves.

Tire Rack carries a variety of coil-overs from companies like Eibach (shown above) who are committed to engineering excellence.

Click here to see a complete list of coil-overs, or shop by vehicle for access to all of the performance suspension products in our inventory.

Now that the KW Variant 3 Coil-Over suspension has been installed and the car re-aligned, it was time to see what sort of improvement in lap times the suspension upgrade brings. KW’s installation and tuning information included with the kit provide initial recommendations for ride height, as well as rebound and compression settings. Figuring this was the best place to start, we dialed in the system to their recommendations, and headed for the track.

We ran the car on both the O.E. Bridgestone Potenza RE050A tires, as well as on our wide Dunlop Direzza Sport Z1 Star Spec competition tires. As expected, both configurations went faster than the last time we drove the car with the stock springs and shocks. Interestingly, the Dunlops gained more than the O.E. tires did, suggesting they have more potential not realized with the O.E. suspension. Subjectively, the car now feels more at home on the track, responding to driver inputs with greater authority than before.