The BMW F80 M3 / F82 M4 is a very capable machine from the factory. They offer a powerful engine accompanied by a great handling package with great tuning capabilities. However, there is still plenty to be gained from the suspension system as a whole regardless of whether the car is used only on the road or if it is driven aggressively out on circuit. The standard spring and damper setup is often described as “crashy” where it feels unnecessarily stiff over bumps in the road. At the same time it also feels too soft when cornering hard out on circuit. This combination is almost the opposite to how we would like the M3/M4 to handle.
Therefore, we have developed a few different set up stages that can benefit every M3/M4 owner to turn such a brilliant chassis and power package into a cornering machine. We have separated each upgrade into 4 handling packages (road, fast road, track and race), being packages (1,2, 3 and 4) respectively.
Handling Pack 1 (Road)
The first stage of upgrades for the M3 / M4 is two stage. The most important step of this stage is a full geometry alignment. Even if you have just collected your brand new BMW from the showroom, a full geometry alignment is still required to help transform your handling for the better. The standard BMW suspension geometry is relatively held back for a number of reasons. Despite the months of testing and development, they still need to abide by certain laws and regulations with regards to tyre wear and safety. They need to give enough grip in the snow, ice and standing water and perform in all of the countries where they are set to sell. Therefore, there is plenty of room for improvement for fast road use in the UK or in your particular climate as we are able to focus the settings to provide high performance through corners in dry or wet conditions that we are used to experiencing.
The first step of this stage is to install lowering springs to the car. The lowering springs should be installed before the alignment as the car will need re-aligning once springs have been installed so getting both done at the same time is highly advisable. The lowering springs lower the car which lowers the centre of gravity and slightly stiffens the spring to help with cornering stiffness, keeping the chassis stay much flatter through corners, inspiring more driver confidence and allowing the car to carry more speed through the corners.
The next step is to have full geometry alignment settings installed on the car you will have improved turn in response, mid corner grip and the speed at which the car can change direction, making the car feel in tune with the driver. The standard adjustment components of the car can be used to adjust the vehicle geometry. With the springs installed and the alignment carried out you will benefit from much better handing without compromising on daily use in a very cost effective way.
Handling Pack 2 (Fast Road)
If you use your M3 / M4 mainly for fast road use with the occasional track day then you will benefit from further upgrades. This is the point where the front wheels are crying out for more camber. The standard suspension system does not offer camber adjustment so an aftermarket part is required here. Camber plates can be installed which can be used with the standard spring and damper aswell as working with lowering springs and many aftermarket coilovers.
The increase in camber provides much more front end grip through the corners, as the car begins to roll onto the tyres contact patch when it is pushed hard. This effect is increased when lowering springs or coilovers are installed too as the stiffer spring allows the car’s chassis to roll onto the tyre even more due to the body roll being reduced. Therefore, if enough camber isn’t present at the front wheels, a large portion of the tyre isn’t touching the ground through the corner which leads to understeer and excessive tyre wear at the outer edges. This is where the camber plates can be installed to address this issue.
Another component to install at this stage is adjustable drop links at the front and rear of the car. This is because, once the car has been lowered, the drop links sit the roll bar in a new position which can cause the anti-roll bar to begin hitting the chassis or other suspension components. With adjustable drop links installed you are able to re-set the position of the anti-roll bar back to its factory position whilst still benefitting from the lowered ride height.
Handling Pack 3 (Track)
If you use your M3 / M4 on track days occasionally or frequently then handling pack 3 is the best route for you to extract the most performance from your car. At this point lowing springs have reached their limit and it is time to upgrade to a good set of coilovers. The reason why you need to upgrade is that although the lowering springs have lowered the car and provided a stiffer chassis, the damper is not quite up to the task of handling the spring as perfectly as it could. With a good set of coilovers installed from manufacturers such as Ohlins, Nitron, KW and Bilstein the dampers internals have a much more sophisticated piston allowing better control over the low and high speed damping. This means that the damper can be setup to be slightly stiffer through the corners but can be softer when hitting bumps, potholes or kerbs so you don’t need to compromise on comfort too much either.
The coilovers also offer ride height adjustment meaning that the height of the car can be set to your preference and some rake can be introduced into the setup to improve the M3 / M4 handling substantially. Furthermore, the ride height adjustment allows the car to be corner weighted which means that the mass present at each tyre is tuned and balanced to improve braking, acceleration and cornering balance substantially making the M3 / M4 perform much better out on track.
Camber plates are still required for some coilovers that are not supplied with them. Some coilovers are supplied with them so they wouldn’t need to be purchased separately. Once installed they allow the front camber to be fine tuned to provide the correct amount of contact patch through the corners to maximise cornering forces and grip.
Another aspect of geometry to consider when building a track M3 / M4 is caster. This is a key aspect of geometry affecting the front wheels that when increased, provides a much more positive feel through the steering and improves cornering performance substantially, particularly on a RWD chassis. The extra caster can be achieved using certain camber plates or by installing off-centre bushes in the front control arm to move the position of the front wheels.
Now that we have lowered the car more, we begin to run out of adjustment using the standard adjustment bolts at the rear of the car. This means that the optimum toe and camber settings cannot be achieved without the installation of some adjustable rear toe and camber arms.
With the adjustable toe and camber arms installed at the rear, the best settings can now be regained for camber and toe, generating far more grip through the corner and in a straight line. The increased camber also provides more mid corner grip, meaning more speed can be carried through the corners and you are able to get back on the throttle earlier to reduce lap times and increasing driving pleasure.
Another component to install is adjustable drop links at the front and rear of the car. This is because, once the car has been lowered, the drop links sit the roll bar in a new position which can cause the anti-roll bar to begin hitting the chassis or other suspension components. With adjustable drop links installed you are able to re-set the position of the anti-roll bar back to its factory position whilst still benefitting from the lowered ride height.
Bump steer adjustable tie rod ends are also an option at this stage allowing you to fine tune the handling of the car. Once the car has been lowered, the bump steer at the front wheels increases due to the new arc pattern on the tie rods. With the installation and setup of bump steer tie rod ends, the bump steer can be removed or reduced heavily so that the front wheels are not altering their toe settings when encountering bumps and undulations in the track surface.
Another upgrade in this stage is to install some polyurethane bushes on the front lower control arms and any rear arms that haven’t been replaced with adjustable arms. This will reduce the flex within the bush meaning that the grip generated by the tyre is transferred into the chassis much faster, making direction changes quicker and more direct, making the car respond in time with driver inputs making the car feel much more intuitive.
One aspect often overlooked is upgrading the brake package. Upgrading to a big brake kit for the front and rear wheels will improve the stopping performance of the car substantially. This means that you can get on the brakes much later, slowing the car down at a much higher rate which will reduce lap times substantially. Match this braking performance with the improved cornering performance and the lap times will reduce rapidly. A good track pad should be used which will switch on from cold through to hot and won’t fade as you press on round the circuit for lap after lap.
With all of these components installed, the car now needs a full corner weighting and geometry alignment setup.
Handling Pack 4 (Race)
The final stage of our handling upgrade packages is for race use. This is the most hardcore settings where the car is only going to be seeing a race circuit. A good set of coilovers is definitely required here with a stiffer spring rate than for the occasional track use. Along with the stiffer spring rate, you might be looking to upgrade your tyre choice to a grippier compound or even start to run slick tyres if your race series allows. This will generate much higher grip levels through the corners but will in turn require a much stiffer spring rate and more static camber present at the wheels. All components that were installed in stage 3 are still required for stage 4 for the same reasons so front camber plates, rear camber arms, rear toe arms and adjustable front and rear drop links need to be installed.
For better coilovers options, 3 way adjustable dampers should be considered to allow for much finer tuning of the damper to control low and high speed damping so that cornering damping can be fine tuned separately to high speed impact damping to ensure that the spring and damper are being used to their maximum potential at all times whilst out on circuit. The car will also be set to a much lower ride height for race use to get the centre of gravity as low as possible.
At this stage, caster should definitely be adjusted and increased on your M3 / M4. This is a key aspect of geometry affecting the front wheels that when increased, provides a much more positive feel through the steering and improves cornering performance substantially, particularly on a RWD chassis. The extra caster can be achieved using certain camber plates or by installing off-centre bushes in the front control arm to move the position of the front wheels.
Bump steer adjustable tie rod ends should also be installed to allow you to fine tune the handling of the car. Once the car has been lowered, the bump steer at the front wheel increases due to the new arc pattern on the tie rods. With the installation and setup of bump steer tie rod ends, the bump steer can be removed or reduced heavily so that the front wheels are not altering their toe settings when encountering bumps and undulations in the track surface.
Uprated anti-roll bars can also be installed for race use, this increases the cornering stiffness of the car without impacting the spring rate of the car. Therefore, you can build a very stiff cornering machine without making the car too stiff on the brakes, throttle or over bumps in the road which provides much more overall grip throughout the length of the circuit. Uprating front and rear roll bars and incorporating adjustment into the roll bar means that you also have the ability to fine tune the mid corner balance of the car. This means that you can fine tune understeer and oversteer characteristics to make the car handle in tune with your driving style which will reduce lap times substantially.
Upgrading the suspension bushes is next. All bushes should be upgraded to solid bushes at this stage. Considered too harsh for use on the road, solid bushes all over the suspension system will provide a harsher, louder ride. However, the handing benefits on circuit are profound. Removing the rubber or polyurethane bushes means that any grip or direction changes occurring at the tyre are transferred directly into the chassis without any flex or play from any connecting bushes. This greatly reduces the time it takes for the car to respond to driver inputs such as turning the steering wheel or applying the throttle. This makes the car change direction faster and becomes an extension of the driver as any inputs are followed by immediate intuitive action by the car.
A big brake kit is definitely advisable for racing as it will not only improve the stopping performance of the car greatly, allowing you to get on the brakes much later, but they also won’t fade as the laps begin to add up. This lack of fade is very important to allow you to set repeatable, fast laps throughout the duration of a race. A good race pad should be selected that might not be very good when cold but as heat begins to build in the disc and pad, the braking performance is much higher without the risk of fade.
How To Get Your Handling Pack
If you would like to get in touch about any of our upgrade options, services or handling packages you can contact us via the Contact Page. All of our upgrade packages and components are available to view in our shop Here.