To many enthusiasts and automotive journalists, the E36 BMW M3 is known as one of the best handling cars in the world. The car's suspension is so well put together out of the box, it becomes almost sacrilege to upgrade. Almost. From the factory the car was set up to accommodate everyday driving situations, at the same time offering the best possible handling performance. But this is a project with the goal of building the most wicked street-legal BMW M3 that will also work on the track. With this in mind, I was more than willing to compromise some of the factory comfort.
The first question concerned what combination of suspension components I was going to put on this vehicle. Was I going to do springs, shocks and anti-roll bars, all at once or incrementally? The answer lay in what my M3 would be used for, which would be mostly street use but with a lot of track time. I was willing to compromise the ride quality of the M3 to an extent, and I wanted the camber, ride height and even the stiffness of the anti-roll bars and shocks to be adjustable, to allow changing from street to track setups and vice versa. So, as you may have already guessed, I opted to go for a full-blown coilover setup.
Which tuner was I going to use? I wanted a company with plenty of experience in racing, particularly with BMWs. Although there were a few good suspension kits on the market to choose from, Ground-Control's coilover kit topped my list.
Ground Control has been designing cutting-edge suspension components for street and race cars for the past 18 years. Several of the fastest ITS E36 BMW race cars run Ground Control suspension, but the company doesn't believe in concrete spring rates for any race car. Jay Morris, founder and owner of Ground Control, who also happens to be a BMW racer, stated, "It is against our basic philosophy to try to convince a customer that what is in a box on our shelf just happens to be the perfect spring rate for his/her car. What we do instead is work with the customer to provide the best spring rate based on their tracks, tires, experience, etc."
As a racing company, Ground Control will not discuss or recommend spring rates unless someone is buying them. This protects its customers as well as the company's intellectual property. "You cannot believe how many people, BMW [owners] in particular, call us and ask, 'What spring rates should I use on my car?' but have no intention of buying them," Jay said. "We respect our customers who are racing; we just don't give away that info to someone they might be racing against."
After several phone conversations about possible setups, Jay finally put together a fairly aggressive racing coilover setup for the Project M3 that would also be tolerable for street use. He used three-way, double-adjustable (for bump and rebound) monotube shocks made by Advance Design, a racing-only shock manufacturer owned by Ground Control. These particular front struts have a modified kingpin angle for more tire clearance, eliminating the need for wheel spacers to clear wider front tires, and they're drawn-over-mandrel seamless alloy with an induction-hardened steel shaft.
The rear shocks are DOM seamless 2024 aluminum and are mounted "right-side up" to allow easier access to the adjustment knobs. According to Jay, any unsprung weight advantage to mounting "upside down" is insignificant, due to the lightweight shock body. The rear shock weighs 25 percent less than stock, and the front, with coilover hardware, weighs 10 percent less than stock, while being stronger at the same time.
Advance Design struts and shocks are assembled by hand in a "clean room," individually custom-valved for each racing application. For this reason, Jay states there are no off-the-shelf dampers--specific damping rates are used to work with the chosen spring rates, weight of the car, and to influence specifically desired handling characteristics.
The stock rear shock mounts were replaced with heavy-duty Ground Control rear shock mounts. Jay reports the unique feature of this part is to allow the rear shocks to be removed from under the car, making it ideal for street cars running subwoofers or M Coupes with rear carpeting that's time consuming to remove. These racing shock mounts are made from heavy-duty 6061 aircraft aluminum.
Ground Control uses Eibach ERS race springs for their coilover setups, and Jay was pleased that Eibach is working with them: "We are very fortunate to be selling Eibach race springs. Eibach not only has an excellent selection, but it allows us to use shorter springs. The ERS springs have more travel in the spring before they coil-bind, which allows us to place the front spring completely above the tire so there is no need for wheel spacers to clear the spring." Eibach ERS springs are cold-wound and shotpeened, and carry a lifetime guarantee.
I was amazed at how easy it was now to tamper with the M3's ride height--it can be done in a matter of minutes. The springs sit on an adjustable spring seat, which can be loosened with a hex key once the car is jacked or lifted. Once loose, the seat can be rotated by hand up and down the threaded sleeve. Count the turns according to the location of the hex nut: Every full turn is a 1/8-in. drop in the front and a 1/4-in. drop in the rear. To lower the car evenly, simply turn the front perches twice as many times as the rear.
When asked which anti-roll bars I should use, Jay quickly referred me to Eibach. Apparently Eibach's anti-roll bars are the only ones that are M3-specific: "Eibach makes an anti-roll bar set for the E36 325, and a completely different anti-roll bar set for the E36 M3. Every other company makes a anti-roll bar set that is intended to fit both cars," Jay said. Needless to say, I called Eibach and asked for a set of M3 anti-roll bars.
The front anti-roll bar measures 26mm in diameter and the rear 24mm, compared to the '95 M3, which came with 22.5mm and 19mm bars. By contrast, the '96-on E36 M3s were equipped with thicker bars measuring 23mm for the front and 20mm for the rear. Eibach sells the same bar sizes for both applications.
The anti-roll bar end links can be attached to either one of two existing holes on the bars--the one nearer the end for soft, the one farther from the end for stiff. Just because there are only two holes doesn't mean they are only two-way adjustable. According to Jay, the interesting thing about these bars is you can adjust one side to stiff and the other side of the same bar to soft, bringing the overall stiffness in between the two extreme settings of the bar, which makes both the front and rear bars essentially three-way adjustable!
To top off this racing suspension setup, Jay sent a set of Ground Control front camber/caster plates. These awesome camber plates are fully adjustable and are designed for racing only; Ground Control sells urethane centered plates for street use. The plates are machined from 7075 T-6 billet aluminum. The markings on the racing plates are referenced to centerline, not zero, making the -2-degree marking actually about -3.5 degrees on a lowered car, according to Ground Control. The weight of the car is supported by needle bearings, not on the center spherical bearing, a unique feature helping the bearings last longer in a racing environment.
Having those markings is a tremendous help when you want to fine-tune your M3's camber setup. No more guessing games--simply jack up both front sides of the car, loosen up the three strut bolts, and push the shock towards the middle or outside of the car until you get your desired camber measurement.
More negative camber (than stock) will increase the life of your tires during track days (although the opposite is true in street driving), while at the same time providing more bite in the front end. Remember noticing how much your side tread had gone down after your first track day? Dialing in more negative camber allows the contact patch to be used more evenly when cornering, reducing understeer and increasing the life of the tire with more even wear. The beauty of these camber plates is that after a track day they can easily be turned back to your exact street settings, without guessing, to reduce wear during your highway commute back home.
Thanks to the suspension experience of evosport, I was able to get a trouble-free install of the Ground Control coilovers and Eibach anti-roll bars. When I went to pick up the car, Vadim Fedorovsky of evosport said, "Well, here it is. It's stiff as hell but handles like a dream!" And stiffer it was. If you were to push down inside the trunk of a stock M3, you'd notice the car squat considerably. Before my very eyes Vadim turned into a 260-lb giddy schoolboy launching himself butt-first in my trunk--he still failed to get the car to even begin to squat.
Of course, I started to worry whether this setup was going to be too stiff for the streets. Surprisingly enough, when I jumped in the car and drove off, it was very tolerable to me. Sure, I never realized how bumpy my local freeway was until now, but it wasn't shattering any of my teeth. When I hit speed bumps the car just felt very solid, whereas I initially expected it would sound like it was going to fall apart from the stiffness, with new, loud noises and assorted creaks. Needless to say, I'm impressed at how streetable this suspension actually is, for my taste at least. If you have small kids you plan to take to school, maybe a softer setup would be more ideal for you. Either way, the beauty of Ground Control is its flexibility in providing you and your car with the best setup for your driving desires.
After a full suspension installation, it's critical to get the car realigned. For this the car went to Louie Lugo of Big O Tires in Redlands, California. For many years I've had cars go in and out of Louie's shop with great success, and I trust his service. With his top-of-the-line Hunter P411 alignment tool (which is more the size of a full-scale dynamometer), we got the car properly aligned before I started tampering with the suspension adjustments. One question brought to mind by one of Louie's technicians was if the car would have to get realigned after each ride-height adjustment.
I immediately contacted Jay Morris. When asked about this, Jay quickly reassured me it wouldn't be necessary: "One of the beauties of the 1995 E36 M3 is the way the Germans set up this suspension. With our stuff on there it would probably take over a 3-in. drop to really affect the toe of the car." He went on to explain the differences between the 3.0- and 3.2-liter M3 suspensions. According to Jay, the 3.2 M3 came with less camber than the '95 3.0, and the lower control arm and tie rods on these newer E36s are not parallel to each other, as they are on the '95s. Although only off by about a degree, this affects the vehicle's bumpsteer, making the 3.2s easier to handle for the average driver on the streets.
"The '96-up M3 bumpsteers inward more when the suspension hits a bump, or, more importantly for us, enters a turn. The '95 M3 pretty much has no toe change when the car enters a turn. The '96-on M3 adds toe-in, [making] the car more predictable. But it adds understeer," Jay explained.
Ground Control's shock housing design brings the 3.2-liter M3's lower arm and tie rod parallel to each other, back to '95 M3 specs. In order to bring an E36 car's bump steer back to stock '95 M3 specs, Ground Control carries different strut housings for the E36 325, '95 3.0-liter M3 and '96-on 3.2-liter M3.
Back at Big O Tires, at the highest possible ride height the coilovers would allow, the car dialed in 0.8 degrees negative camber for centerline. For the street I chose to crank it down an extra degree, giving the M3 a total of 1.8 degrees negative camber, for reasons of having to run a larger wheel spacer to accommodate big brakes with my 17-in. IFG wheels (stay tuned for the brake write-up). I had to dial in some negative camber to avoid my front tires rubbing under hard cornering.
Even though the Project M3 now has what I believe to be one of the best suspension systems available, it will take some tinkering with to get the right setup for my particular car and driving style. I will report back with my track test findings frequently. In the meantime, stay tuned for more performance
Part 1: Getting a feel for the car
One of the things I will cover throughout this project series is a variety of track-testing days. These will range from driving impressions concentrating on newly fitted parts, exit speeds to full lap-time comparisons.
I had only spent about two week's worth of track days in my previous '97 M3, so I was aching to get back to the track with this one. If you've never taken your M3 to a high-performance driving school, I highly recommend it. It's a humbling experience at first, and you'll really learn to appreciate what you and your car are capable of. As a matter of fact, this could be the best upgrade you and your car could benefit from--learning to work together in a real high-performance situation--before investing in performance parts. What's funny is, the more schools I attended, the slower I found myself driving on public roads, as if I got the "speed bug" out of me.
I took the project M3 out to a high-performance driving school event at Willow Springs, hosted by Driving Concepts. It was ironic that I brought the Project M3 to this track first, since I laid my last M3 to rest here nearly a year earlier. In the first 30-minute session, I went out on my own to reacquaint myself with the 2.5-mile, super-fast road course with some easy driving. I really thought this car would be similar to my previous M3 at this track. Because of the difference in differentials and torque curves between the two models, my shift points and gear selections were considerably altered from the last time I was here.
In the second session, Carl McGinn, cofounder of Driving Concepts, jumped in with me to further polish my skills (if any). Thanks to those several minutes with Carl, I was able to dramatically improve my smoothness through some of the turns I was having more difficulty with (he actually asks you first which turns you would like to work on most). In the end, I found myself much more relaxed, while at the same time going much faster--I don't think I'd ever gone full-throttle from turns five through eight at 120-plus mph on non-R-compound tires, let alone all-season rubber!
Carl has a really professional way of pushing you to your own limits--keeping you relaxed and confident--while not being too pushy at the same time. Although Driving Concepts has only been around for a couple of years, Carl has been a professional instructor in the industry since 1985. His expertise has been used in ride & drive programs with the like of Mercedes-Benz and BMW, and training celebrities such as Ricky Schroeder and Danny Glover for the Long Beach Grand Prix Celebrity races.
Then a few years ago, he co-started Driving Concepts. "I saw a need for people to be trained to drive their own cars," Carl said. The schools offer high-performance to full-race instruction, and although mostly dominated by BMWs, any car is welcome.
With the Advance Design coilovers in there, it was obvious this suspension was too much for the tires. Although the Pirelli P7000 Super Sport has proven itself to be a great all-season, high-performance tire, it was losing adhesion sooner than the car would even begin to lean. Maybe it was a blessing in disguise, because the tremendous understeer (incorrect anti-roll bar links prevented the Project M3 from having an Eibach rear anti-roll bar by this time) I encountered throughout the day kept me at speeds I could handle. In the manner this car responded to quick turns and track bumps, it became apparent this coilover setup was still beyond my driving capabilities.
In the next track day we'll see the comparisons between my experiences this day and driving with R-compound tires. What the heck, I may even crank the camber down a bit, play with the caster, adjust the bump and rebound, adjust the sway bars, lower the car some more, play with tire pressures and....
Maybe I should take it easy. But one thing is for sure: I've got a lot of stuff to test in this project. Stay tuned. Author's note: When you try out a new performance modification, understand the importance of safety by testing in a controlled environment, such as a driving school, and testing in a controlled manner.
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Ground Control Suspension Systems