We got Granatelli Motorsports, Corsa Performance, and SCT Performance to lend a hand in the process of taking this showroom stocker to a modified late model muscle car it always dreamed of becoming.

There is a reason most enthusiasts start their aftermarket lives with doing an intake or exhaust upgrade. These basic modifications provide the necessary foundation for other go fast parts such as heads or a performance cam. But to really get this car’s tires screaming, we also added a custom tune from SCT Performance.

Here is a brief overview of what we installed:

• Granatelli Motorsports G8 Cold Air Intake System (PN 500015-P, $279.99 retail)
• Corsa Performance Dual Rear Exit Exhaust with Pro Series Tips (PN 14950, $1,309.95 retail)
• Custom Tune from SCT using the X3 Power Flash Programmer (PN 3400, $479.00 retail)

Let’s take a closer look at the parts we installed, starting at the intake.

Granatelli Motorsports G8 Cold Air Intake System

One look at the design differences between the stock and the GMS Intake make it crystal clear as to why this intake can increase power. Where the stock system is littered with different chambers and bends to keep intake noise to a bare minimum, the GMS version utilizes a large tube with gradual bends to maximize air flow. But it has more than that. One key item found in every intake is the filter. “To help keep costs down, the OEMs equip new cars with your standard paper air filters. While these systems do a fine job of trapping dust and debris and keeping it out of the engine, they are horribly restrictive and limit power,” said JR Granatelli, owner of Granatelli Motorsports.

Granatelli includes a cone style high flow filter with their system. Unlike the factory paper filter, this dust trap can be washed and reused instead of just being replaced when dirty. That helps you keep your engine breathing clean without the burden of purchasing paper filters all the time, so you’re not just getting more air – you’re also reducing the amount of trash that ends up in the landfill over the life of the car.

From the filter, the air travels through the stock MAF sensor and through the large 4-inch diameter tubing on its way to the throttle body. GMS offers three different finishes for this intake: satin, black, or polished like ours. All the clamps and hardware needed to complete the install are included as well.

Installation of the GMS Cold Air Intake

Out with the old stock intake to make room for the new GMS setup.

Anyone that can change a light bulb can install this intake. It all starts with getting the stock rat maze intake out of the car. This is easily done by loosening the clamps that hold the system together, along with with popping the clamps on the filter box and removing the bolts that hold it in. This took about 5 minutes to complete, and we were ready for the GMS Intake.

The polished GMS intake tube is a far cry from the weird blow-molded factory airbox.

First up was the section of tubing that would connect the throttle body to the MAF sensor. This was installed by slipping the rubber coupler over the throttle body and connecting the first finished bend tube in place. From there, we added another rubber coupler and attached the MAF. The rubber couplers were held in place using the supplied clamps that Granatelli Motorsports includes with the kit.

The stock MAF is reused.

We attached the remaining components to the inlet side of the MAF sensor, and finished it off with the cone filter at the end of the system.

The installed system is simplicity itself compared to what we started with.

Corsa Performance Dual Rear Exit Exhaust with Pro Series Tips

More air in means more air out. To give the exhaust gas direction, we picked up Corsa Performance’s Dual Rear Exit Exhaust with Pro Series Tips. Corsa spends an insane amount of time in the design phase of their products, and the products that come out of their building show their attention to detail.

One thing Corsa prides themselves in is creating an exhaust note that’s custom designed to provide a pleasurable sound. While everyone has their own opinion on what a good exhaust sounds like, Corsa’s thoughts are clear. “We pride ourselves in producing an exhaust that fits good and has no drone,” said Craig Kohrs of Corsa. “Noise is not sound to us. We have the technology to be able to fine tune the exhaust sound to exactly what we want it to be,” he explained.

Fit and sound aside, the Corsa exhaust has other benefits as well. The mandrel-bent system helps the exhaust gas flow 68% better according to Corsa. They also claim a significant weight savings. “We were able to really lighten this system up and ended up removing 11 lbs on each side,” Kohrs said. “That means this kit is 12% lighter overall compared to the stock system.”

The fit and sound are what can really make an exhaust, though. The flow claims seem plausible, and just looking at the bends and design of the muffler on the Corsa system compared to the stock counterpart makes this point clear. “If you wanted to, you could drop a golf ball in at the top of this system and it would roll right out the other end, even through the muffler.” explained Kohrs. “That is how open this exhaust is.”

Exhaust Installation

The stock mufflers are designed to be inexpensive and durable, but that's about all the nice things you can say about them.

Removing the stock exhaust system was simple. GM did a nice job designing this car to be easy to work on in this situation. The stock exhaust sits pretty much below everything, including the independent rear suspension. That meant all we had to do was unbolt a few clamps and we were able to start pulling tubing out of the car.

The stock "H-pipe" with built in resonator bears an uncanny resemblance to the same piece on the 5th-gen Camaro.

Up near the front of the car, we unbolted the stock H-Pipe and got ready to install the new Corsa kit. We chose not to remove any other components of the car including heat shields or brackets for two reasons. First, many of the brackets were going to be reused with the Corsa kit. Second, we wanted to test the fitment of the kit with as much of the original equipment as possible.

The Corsa kit is designed to fit like a factory system, and reuses the stock mounting locations.

The stock exhaust unbolts just after the catalytic converters, and that is where the Corsa system picks things up. The system starts out with a pipe that connects the plumbing after the converters to the the rest of the system. In doing so it also moves the exhaust to the center of the car, following the path of the stock exhaust through the midline of the vehicle.

Flex couplers just ahead of the new mufflers keep rattles at bay by providing for expansion as the system warms up.

Once making the turn back toward the outside of the car, Corsa places a flex joint here. This is to help compensate for the expansion and contraction that stainless steel can experience in different temperature ranges. This also helps keep the amount of squeaking and rattling down.

Dual large-volume mufflers keep the dB's under control without restricting flow.

Before long, our GXP was ready to be lowered off the Bend Pak lift. The last thing we did was hang the mufflers and tighten everything down.

Though the intake and exaust will provide performance gains on a GXP with the stock tune, we wanted to get everything we could out of our new combination with SCT's help.

SCT Tune

To really take advantage of all the free flowing air, we decided to add a custom tune from SCT. First, we wanted to get a base line of the horsepower before the tune, so we moved the GXP over to the DynoJet 424x dyno and made a total of two runs. The numbers were impressive. The LS3 turned out a solid 365 horsepower and 367 ft/lb torque. Not bad for a factory tune with a few bolt-ons.

SCT said they could do better. The weapon of choice for SCT’s own Chris Johnson was the X3 Flash Tuner. This power tuner would allow us to make the necessary changes to the G8’s computer to really bring out its inner muscle car. “We went with a performance tune that is very similar to what we would do to the Corvette or Camaro with the same engine,” said Johnson.

The wide open throttle fuel and timing maps were adjusted to ensure the right amount of fuel and spark was being delivered to the engine at the right times. Johnson also added, “Because this car already had an aftermarket intake and exhaust, we used our tune that corresponded with those upgrades. That way we were able to get the most power out of those modifications.”

One thing that many owners have brought up with these newer cars is the lack of “feel” behind the pedal. This is due to the advent of Drive By Wire technology that has replaced the traditional cable that once linked the pedal to the throttle body. “With the X3 we are able to tune the Drive By Wire system and give it a more responsive feel that you would normally associate with the older cable systems,” explained Johnson. In addition to that, the SCT tune adjusted the computer’s Torque Limiters to let the engine work more comfortably without being held back. It also removed both the rev-limiter and speed limiter. At this point our G8 was ready for anything!

The X3 is such a powerful tuning tool, that it also lets you perform custom tuning on your car. You can adjust fuel percentage, timing, and even shift points on automatic cars. So even if you think the tune that comes with the device is powerful, picture what you could do after fine tweaking it for the best results.

After a few quick minutes, the tuning process was complete and we were ready to pull the car back onto the DynoJet dyno to see what kind of results we got. The results were impressive. We saw 380 HP and 381 TQ, an increase of 15 WHP and 14 WTQ! Keep in mind that this is on top of the gains we’d already seen from the intake and exhaust.

With no more than a day’s worth of work, our silver GXP that once blended in with the crowd transformed into a growling, easy breathing pack leader with close to 400 rear wheel horsepower. The best part is that all these mods are easily accomplished by anyone who knows which way to turn a wrench using only common tools. The fit and finish of both the Granatelli intake and Corsa exhaust are up to the high standard we expect for our G8, and the SCT tune not only got us more power, but also improved how the Pontiac drives at part throttle as well.

The Evolution of the Budget Summer Performance Tire

Through the 1990s there was a shift in what first-time car buyer enthusiasts wanted out of their budget performance vehicle. There was a shift from a mostly drag racing centric market to people that cared more about speed through the corners. Up until the late 1990s, if you wanted a sticky summer performance handling tire, you were going to pay an arm and a leg for them. Used tire depots became a popular place to try to find lightly used sets for a bargain, because most couldn’t afford $1000+ for a medium sized 17-inch set that were new.

Tire manufactures realized this and the younger companies began to introduce budget performance tires in the late 1990s, while more prominent names were too proud to create a Casio version of their Rolex tires. For the smaller companies, the budget performance summer tire served as the heartbeat that made them grow larger as this trend grew fast. Now young enthusiasts had the ability to buy brand new performance tires for pennies on the dollar.

These tires offered stiff side walls to reduce flex under cornering, decent water grooves for light rain driving, and a soft compound that did not require warm up to work well. Before anyone knew it, these budget tires became the choice of autocross classes like STS and STX that were street tire only classes, and were nearly banned for performing so well. The problem with early generation versions, is that they would have a narrow operating temperature and would get greasy if they were run hard for an extended period of time – the polar opposite of an R-compound.

Procedure Nitto Takes on Designing a New Tire

The NT555 has been a flagship tire amongst Mustang enthusiasts especially for years, but Nitto new this design was dated and needed an update. When it comes to developing a new tire line, the first measure Nitto takes is to make sure that it does not directly compete with any other of their tire lines. Taking from their mantra, “Fueled by Enthusiasts”, Nitto gets feedback from shops and manufactures on their new idea, analyze current popular vehicles for sizes, analysis on competing brand designs, going to new car shows, and take surveys at various races or events.

Nitto's Miyazaki test course in Japan

For a design concept, Nitto uses a team of designers to draw up possible tread designs that unique, but that can also be functional. The Japan head office then has the technology to analyze the designs to find out which ones will be the most suitable, along with the tread compound. “We use proprietary software that allows us to analyze on pattern noises and make adjustments in the software to compensate for that,” Stephen Leu of Nitto remarked. Once this is done, a hand cut tire prototype is made and reviewed before final design is agreed upon. This even includes the font and logo designs on the sidewall of the tire. From there, prototypes are developed and testing is underway.

Nitto relies mainly on their test facilities (two facilities that include off road and high performance driving) and their sponsored motorsports drivers when it comes to feedback before the final compound and construction is locked in. When it comes to developing different sizes, a new mold has to be purchased. “Similar sizes can be covered by one mold is some cases”, Leu says. “It isn’t labor intensive when introducing a new size, but there is a large monetary investment by having to buy a new mold.” During this whole process, which can take over a year, the team at Nitto is constantly monitoring market trends to make any adjustments before final production takes place.

Nitto’s New High Performance Summer Tire – The NT05

The design of the NT05 stems back to 2007 from when the first ideas were conceived. Working through nearly two years, Nitto released the NT05 at the 2009 SEMA Show. They now currently offer about 25 different sizes. “With our initial sizes developed for the NT05, we went after the current popular vehicles like the Challenger, Mustang (1994 to current), 2010 Camaro, WRX, Evos, BMW series, to name a few.” Nitto prides themselves in being one of the few (if only) that offers a summer performance tire in this range for 20-inch wheel equipped vehicles.

Features of the NT05

At first look at the NT05 you can see how square the tire is. This helps push the maximum amount of traction down to the concrete, including the minimized rain grooves for added rubber

• Reinforced shoulder tread blocks and three ply sidewall construction provide exceptional rigidity and stability
• The continuous center rib consistently provides optimum tread contact with the road to maximize dry performance
• The specifically engineered silica-infused (silica is what helps the tires stick to the road) and reinforced internal construction enhance construction, handling and high speed capabilities.
• High tensile steel belts increase tread stiffness
• Spiral wound cap ply provide stable high speed performance and improved uniformity

Hard Core Driving Characteristics

The one concept Nitto knew they wanted with the NT05 was its consistency. They wanted a tire that will constantly perform through its heat cycle and not become plagued from overheating while running them hard. Even though the NT05 is a great street tire, it’s built perform on the race track.

Talking with Nitto Engineer Alan Ngo, he told us a little about the NT05. “The operating temperature of NT05 is 160 to 220 degrees,” said Ngo. “Given that there are a lot of variables in play to heat up a tire to optimal temperature, like the weight of vehicle, the camber, and length of track, the average laps required for the NT05 to heat up will be 1-2 laps.”

Even during its limited time to market, the NT05 in motorsports has been used by Matt Dennison during 2009 time attack events under the Stock Class AWD. In the 2008 Super Lap Battle, Ryan Gates used the production sample of the NT05 (before the product release) and received second place. This is the first time the NT05 was used for competition purposes.

Mounting our NT05s is just like mounting any other tire, though when it comes to plus sizing, putting the tire onto the rim becomes more challenging. Select a reputable installation shop for mounting tires onto new wheels. If care isn't taken when mounting them, you could end up with scrapes on the lips of your new wheels

Testing the NT05 with Forgeline Wheels on our G8

One of more popular projects lately has been our Pontiac G8 GXP. Equipped with factory 19-inch wheels and tires, and a performance-tuned suspension, it has been called a 4-door Corvette. We decided to up the ante and perform testing with Nitto NT05 tires, 245/40/19 and 285/35/19. To fit the extra size rear tires, we went to our friends atForgeline Wheels and had them whip us up some custom GXP sizes that will perfectly fill the wheelwells and give the GXP a wicked stance.

We spoke with Forgeline executive David Schardt who designed a set of S03P wheels with some custom design flairs. Gloss black powdercoat with what Forgeline calls their “Diamond-edge” finish – which is the diamond-cut effect you see on the edge of each spoke.

Forgeline is one the best custom wheel makers in the business – building light, high-performance racing wheels that can be driven daily on the street. But the real magic is the Forgeline sauce is the custom offsets – you see Forgeline has their own in-house CNC equipment, so they can custom made almost every single offset known to man, even as tight as 1/8-th of an inch.

Although Forgeline won’t give away the information on the G8 offsets they made for us, rest assured, they will build you a set, and you can fit perfectly the 19 x 10 and 19 x 9.5 wheels that we chose. The only thing worth mentioning – with this wide tire we chose, we did need to roll the fenderlips!

Driving Impressions

Unlike many competition tires, the Nitto NT05′s were fairly sticky from minute 1 of our testing driving. The stiffer sidewalls gave the car a firmer side than the O.E. rubber, but not so firm that driving, potholes, and speed bumps were uncomfortable. The tire felt more stable under cornering and that confidence extended to the driving experience. After about 5 minutes of hard driving, we did feel the tires get a little more grippy, especially when pushed to the edge. Straight line traction was impressive — full throttle in first gear with the traction control disengaged did produce some moderate wheel spin, but an impressive amount of stick for a 390 rwhp car on regular street radials with a 5-speed.

In terms of comparing this to Nitto’s existing line, the NT05 occupies a very nice niche for the late model Muscle car. The NT555 is a great tire – less expensive and certainly a slightly older design, but it doesn’t provide the performance of the NT05 with dry traction. The Drag Radial works fantastic for straight line power, but doesn’t offer the handling flexibility or wet handling that the NT05 brings to the table.

All in all, the Nitto NT05 is a perfect upgrade to the NT555. If our words don’t do the trick, you should see our smile behind the wheel.

Why let the Aussies have all the fun when we could look to upgrade the already impressive stock Nurburgringer-tuned FE3 suspension package with a couple of extra goodies from Whiteline, Eibach Springs, Forgeline, and Nitto Tires? With this undertaking, we were looking to turn a good suspension into a great one with a few smooth moves of our own.

Why Modify?

With a respectable suspension under the car already, why would we want to play around with the existing suspension? Because handling characteristics and preferences are highly variable. They change from driver to driver based on driving style and driving environment. Straight from the factory, the suspensions are tuned for a broader range of street driving that encompasses driving styles from 16 year old gear grinders to 61 year old mid-life crisis drivers. For our road racing sedan, we wanted to fine tune it a bit more and bring out the beast in our “captive” import.

Bone stock from the factory, the G8 GPX already has a good suspension and fierce stance.

About Our Partners

Whiteline, our suspension experts on this project, are based in Minto, Australia, and have over forty years experience in manufacturing sway bars. Whiteline now carries a full line of suspension components in two different lines: Whiteline Flat Out and Whiteline Plus. 

Forgeline is one of the leading wheel companies making high end custom forged wheels in the performance industry. With wheels available in over 100 color and finish combinations, and from 17 to 22 inches, General Manager David Schardt helped us build a unique, stylish, and high performance wheel for our GXP.

Eibach is a family owned and operated company that began when Heinrich Eibach started producing springs in 1951. Today, Eibach manufactures springs for almost every application and type of driving. From F1 and Nascar racing to desert racing or street cruising, Eibach makes springs that help the performance and handling without breaking the bank.

Nitto Tire is one of the most innovative performance tire companies in the aftermarket. With a wide range of offerings from street, to strip, to auto cross, Nitto makes a great performance tire for every vehicle and niche.

The Parts


Modifications started with the wheels and tires. Forgeline set us up with a set of their “S03P” Forged wheels, 3-piece, custom set up for the GXP with the correct widths: 19 x 10 (rear) and 19 x 9.5 (front). We had an almost unlimited choice of finishes, but we settled on Gloss Black wheel finish, with a Diamond Edge finish with a polished lip.

Tires from Nitto Tire were NT-05 tires, 275/35/19 and 245/40/19. The NT-05 tires are a maximum performance summer tire, very aggressive for the ultimate in handling.

Polyurethane bushings have been the bushing of choice for enthusiasts since their introduction into the marketplace in the 1970’s. They replace the soft rubber bushings and provide improved and predictable handling characteristics and have become an economically sound upgrade. Whiteline’s bushings are manufactured with a long-chain polymer compound with additional polyurethane constituents that allow for progressive resistance. The result is a bushing that is soft enough to handle low speed vibration and road noise yet still offers the abrasion and tear resistance of a harder urethane compound. Andrew Nolan, Product Manager at Whiteline Automotive in Comersby, Australia, explained, “That range of product is known as Whiteline Plus and delivers low speed ride quality and high speed chassis control.”

Features and Benefits

Key benefits of all WHITELINE PLUS polyurethane bushings include he ride quality of rubber bushings with the performance of solid links.

• Long lasting durability.
• Resistant to chemicals, oils, and weathering.
• Enhanced handling, steering response, and road holding stability.
• Increased braking capacities and positive brake pedal ‘feel’.
• Wheel alignment rectification and optimization using offset and adjustable bushings and arms.

WHITELINE PLUS Individual Bushing Specifics

Whiteline Plus Spring Eye and Shackle Bushings provide more free pivot in spring length changes under bump and droop loading which enhances overall maneuverability of the vehicle. Adding the Whiteline Plus Shock Absorber Bushings helps to eliminate the shock valving lag at low speeds, even if the vehicle is equipped with heavy duty hydraulic or gas shocks. The Shock bushings enhance the performance of both new and used shocks by its density and linear flow properties which ultimately enhances the shock’s ability to cope with extreme bump and rebound travel.

Whiteline's strut bushing on the left compared to the stock strut upper bushing on the right.

Also available in the WHITELINE PLUS line is Steering Rack Bushings which help to promote stability of the steering rack and Trailing Arm Bushings that eliminate launch and driveline shudder under heavy loads. The bushing characteristics of the Trailing Arm Bushings allow for temporary pinion angle changes where a stiffer or softer bushing allows too much or too little flexibility causing premature tailshaft or gearbox failure.

WHITELINE PLUS Radius Rod/Caster Bar Bushings and Control Arm Bushings enhance handling characteristics by retaining the optimal suspension geometry. In addition to helping the vehicle perform with crisp response, these bushings optimize braking capabilities and provide better feel and stability.

Whiteline's 22mm X-Heavy Duty, adjustable sway bar installed on our project car.

Rear Swaybar. 22mm X-heavy duty, blade adjustable (BHR82XZ)

Designed to minimize body roll and spread cornering loads evenly across the tires, these swaybars provide more grip. The adjustability of the swaybar allows for tuning of the suspension without replacing the entire swaybar.

• Allows for 3 points of adjustment.
• Improves handling while minimizing body roll.
• Allows for better tire grip which improves handling.

The slightly smaller, non-adjustable stock front sway bar (top) and Whiteline's 26mm X-Heavy duty, adjustable sway bar (bottom).

Front Swaybar. 26mm X-heavy duty, blade adjustable (BHF 62Z)

Providing a link between the left and right hand side of the suspension during cornering while minimizing the vehicle’s body roll, the 26mm swaybar ensures a more confident feel to the driver by improving tire grip on the road surface.

• Allows for 4 points of adjustment.
• Tunable for precise handling bias.
• Manufactured with the finest grade spring steel.
• Powder coated finish.

Whiteline's sway bar bushing being installed on the rear sway bar.

WHITELINE PLUS Sway Bar Bushings

• Increase bar rates by 10-20%.
• Reduce lag in the suspension as the bar moves.
• Pivot at both mounting points, utilizing entire bar length.

According to Nolan, the Pontiac G8 has an “unpredictable oversteer characteristic” that is evident in all G8 vehicles. “The front 26mm adjustable sway bar counters the oversteer and provides four distinct stiffness settings allowing for precise handling adjustments. Cornering loads are spread more evenly across the tires delivering more grip, and that’s what it’s all about. You get improved tire wear as your tires stay flatter and more upright.” Nolan went on to say that nothing is sacrificed to achieve better handling. In fact, he stated, “Comfort improves because your car sits flatter through the bends meaning less movement inside the vehicle.”

Whiteline's front sway bar bushing.

Installing Whiteline sway bars and bushings improves the ride and driver comfort, promotes better tire wear, and provides more tire grip in the corners. Sounds like pretty good bang for the buck performance modification to us.

Other Upgrades

We had a couple more upgrades we wanted to make to our project car before we took it to the streets. We turned to the Whiteline Strut Brace for additional support up front and the Eibach Lowering Spring Kit to bring the roll center down. The addition of these two final upgrades would propel the handling to a superior level compared to a bland, sloppy handling that arrives off the showroom floor car. Looking forward to turning our muscular street performer into a real canyon carver, we eagerly began installing these final components.

Whiteline Strut Brace installed on our project car.

WhiteLine Strut Brace (KSB637)

Strut braces stiffen up the front end of the chassis and eliminate the chassis flex that takes place under heavy acceleration, deceleration, and hard cornering. If you like pushing your car harder through corners than the average driver, a strut brace is a must. Our good friends at Whiteline explained that their strut brace helps maintain alignment angles and spring rates; a difference that can be felt in sharper steering response. Featuring a lightwieght alloy construction, they are strong and look great on the car.

Whiteine's strut brace is a must for taking corners aggressively.

Eibach Pro Kit (38137.140)

According to our sources at Eibach, the Pro Kit for the G8 utilizes Eibach’s legendary coil spring system that improves performance and appearance simultaneously. The Pro Kit lowers the car’s center of gravity and reduces rear end squat during hard acceleration. Eibach’s published numbers on the ride height lowering is 1 inch in the front and 0.8 inch in the rear. Combining the Eibach Pro Kit with the Whiteline sway bars intensifies the ground hugging effect during cornering.

Eibach's lowering spring compared to the stock spring.

Installation

The installation for the Whiteline Sway Bars and Strut Brace with Eibach was pretty straight forward and took less than an afternoon to complete. We did find it easier to remove and install the front sway bar by unbolting and lifting the engine up a couple of inches using a two post lift and a hydraulic underhoist jack. If this option is not available, the sway bar can still be removed by loosening the steering rack and power steering lines.

Tips on Whiteline Sway Bar Installation:

• Installation should be done at ride height. If this is not an option, the bolts should be tightened at ride height to avoid preloading the sway bar.

• Apply polyurethane grease to the contact surfaces of the new polyurethane bushings.

• When setting the adjustments on the adjustable sway bar, always start with a softer setting then adjust to a harder setting if needed.

• Use caution to not over tighten the sway bar pin links. The nuts should be tightened until the washer and bushings stop rotating, then turn 2/3 rds of a turn tighter.

• Check all fasteners after 50-60 miles of road time. This gives the components a chance to “settle-in”.

Eibach's progressive lowering spring.

Eibach Pro Kit Lowering Spring Installation

Strut springs should only be replaced by a technician with experience in changing strut springs, and only the proper tools to perform the task should be used. Springs are under pressure and can cause serious injury if the proper precautions are not taken.

Changing strut springs using spring compression tools.

Eibach Springs Installation Tips:

1. Measure vehicle’s ride height before starting installation and then again after installation. This will tell you how much the vehicle has been lowered.
2. Measure from the top of the wheel rim to the highest point on the fender well. After driving the car for 10-15 miles, remeasure the height to check for settling of the springs and spacers.
3. Before removing the strut assembly, label each part from top to bottom in sequential numbers. This will ensure that you will reassemble the parts in the correct order.
4. Draw a vertical line with a marker across all the components. This helps re-installation of the OE parts in the original orientation.
5. Mark the position of all alignment-related bolts. This will give you a decent starting point to work from in the post installation alignment.
6. Work from one corner of the vehicle at a time. If you get confused during re-assembly, you can refer to the corresponding assembly for reference.
7. Re-install all fasteners in the same orientation as they were removed.
8. Use spring compressors when removing springs from your car or from the strut assembly.
9. Note the orientation of the OE springs and install the Eibach springs the same way in the spring seat.
10. Re-torque mounting bolts after 500 miles.

Finishing the Job

With all the parts installed, we rolled our G8 out of the garage and asked the car owner to drive it for 20-30 minutes. With instructions to drive it hard to “seat the components”, we sent our driver out into the world. Before the installation, the driver complained that the “car feels solid but the rear end is slightly loose. There is a lot of body lean when you turn sharply, and during braking there is substantial nose dive.”

We felt confident that the driver would return with detailed analysis of the changes and, as luck would have it, as we were finishing up the shop clean up, our driver returned with a big smile on his face. When asked about the handling, our driver candidly explained that “the car stays much flatter during rapid quick steer movements, it has much quicker turn in, and the oversteer is gone.

The rear of the car feels very comfortable in hard turns”. His overall assessment of the new suspension changes were summed up with, “I love the looks with the lowering of the car, the easy ride, the firmer but certainly livable handling, and my confidence has improved big time. Now I feel like a true serious sport-touring driver.”