Welcome to the BMW M4 GT4 release notes blog. In this page you will find the detailed notes compiled by the team after each session when creating the fast and safe variants of the new CDA3 BMW M4 GT4 setups. In addition, a complete list of the driver and engineer combinations for each track is present so customers can see which driver and engineer worked on that circuit when looking for setup trends.
- Brands Hatch uses the Laguna setup as a baseline but runs a much more aggressive damper setup for entry rotation to aid in high speed cornering through the final sector.
- The rear bumpstop rate has been kept quite soft to work in conjunction with the dampers to increase rear grip and traction through the off-cambered sections of the track.
- The safer variant has a stiffer front damping which makes it more forgiving over kerbs and grass however it is also limited on entry rotation giving slightly more understeer through the final sector.
- For Misano we have opted to use a very soft spring setup because the track has multiple low traction zones and off throttle sections which require enough roll compliance.
- The reason the roll bars are not adjusted for this compliance is to make the car stable through the high speed corners.
- In order to increase the traction even more, the rear dampers have also been set up quite soft. It was observed that a softer rear rebound provided more mid corner grip on the rear compared to a stiffer setup, despite causing more pitch on entry into corners.
- The differential however has been set up with a relatively high preload compared to other tracks however, and this helps rear end stability through the higher speed off throttle sections. An alternative to this approach is to control pitch with damper adjustments and run a low differential preload to increase rotation, however the traction compromise with the current setup works better.
- General car characteristic is understeer on direction change and high speed so most of the setup is built around getting rid of that understeer.
- While the car eats kerbs for breakfast and so no compromises needed in that regard, you still need to hit the chicane kerbs with the right steering angle to prevent the car bouncing and pogo-ing its way to the Nordschleife.
- Safe set is planted and predictable but loses a bit of pace in comparison to the fast set which is set up to be a bit more aggressive.
- Low downforce philosophy used here for the race setup to maximise overtaking opportunities and defence of overtakes on the main straight.
- Soft roll bars used to help with traction and corner grip.
- Rear bumpstops slightly softer and higher range than other CDA setups, to help reduce oversteer under power in S3 caused by bumpstop engagement being too harsh.
- Soft front springs and medium rears to give aggressive bias to help rotation.
- Safe setup uses changes to dampers, ride heights and wing levels to give a more stable car mid to exit of corners.
- Nurburgring setup used as base.
- Stiff rear roll bar to improve mid-corner rotation.
- Maximum rake and a lower wing to help reduce the high speed understeer inherent with GT4 cars.
- Soft front and medium rear stiffness springs to also help with the aggressive nature needed for rotation.
- Low rear bumpstops to help rotate the car under power with a medium stiffness used as best balance between performance and ride handling.
- Safe setup uses softer rear roll bar and less rake, along with some other minor changes to help with predictability.
- Quali setup uses more aggressive wing and damper settings for maximum performance.
- One of the main challenges with the M4 around SPa is to get it to rotate enough on off throttle and high speed sections without sacrificing traction on the numerous slow speed corners.
- The wing has been run quite low, and the rear suspension/dampers have been stiffened to a very high level to maximise rotation. The traction is regained with the help of a softer front rebound (to load the rear tyres quickly on initial throttle application) along with a low preload to maximise the grip beyond the apex.
- The combination of settings used may appear quite different at first glance but the approach is basically similar to the other tracks, albeit with lower wing.
- Maximising high speed rotation is the main goal, with traction being a secondary priority with the current compromise. In the safe set another click of rear wing has been added which makes it more front limited throughout the track, however the medium speed corners are much more forgiving.
- High rake with reasonably high downforce used as the track has a high speed cornering nature.
- Short (but not minimal) rear bumpstops used as a balance between rotation and minimising oversteer on power at the exit of turns.
- Dampers tuned to give responsive but stable handling.
- Aggressive roll bar tunings used to help mid corner rotation.
- Minimum spring rates to maximise grip at such a low abrasion circuit.
- Relatively low front bumpstop range to limit squat into T1, and behaviour over kerbs, especially in the Degna corners.
- Safe setup uses a softer rear rollbar and bumpstops for better traction and predictability.
- Qualifying setup uses a much more aggressive driving setup to extract time.
- A high rake and low diff approach we found is needed for the long corners to help get rotation and look after the front left tyre.
- You will find that you get one fast lap (maybe two with a safer set) and then the pace will start to suffer due to tyres overheating, especially in hot weather.
- The safe set results in lower temps as it doesn’t work the tyres as hard but it has less potential.
- The Zolder setup uses a high rear spring stiffness and relatively low differential. This helps in high speed entry rotation into the first few corners and the low preload helps in better compliance on exits despite the expectation to oversteer with an open diff on faster corners. The compromise has been made with a slightly lower rear ride height to keep the car stable through direction changes in the next sector.
- The chicane for the most part is quite stable but the landing after jumping the first kerb might catch the car out with the wrong line. If the impact is too aggressive consider softening the rear bumpstop rates slightly, but keeping the rear dampers as is. Stiffening the rear dampers too much will cause the rear suspension to be overdamped and not compliant enough on landing. The advantage of a stiffer rear configuration lies in high speed corners.
- For the most part, the rest of the setup follows a similar approach to most of the high speed tracks in the list. Oulton Park is a good starting point to try a different driving style at this track. Consider using the Oulton Park setup with a slightly lower ride height for a safer alternative around this track.
- The car inherently understeers on high speed and has traction loss in slow speed exits similar to its GT3 counterpart.
- The ride height is therefore run quite high with a stiff rear suspension to get maximum exit rotation. The stiffness of the front dampers also helps in controlling pitch into corners with the current suspension setup.
- SInce the car is setup to be non compliant at high speed and into braking zones, the differential can be run much lower than usual. This has also proved to help in traction out of slow to medium speed exits.
- Running too much front toe (negative) was observed to oversaturate the tyres into the corners too early which adds to the understeering characteristic of the car. Consider adding more preload to delay the saturation if maximum toe works better as per driving style.
- For Donington Park, the front springs have been set up to be quite stiff. This works in conjunction with a change to the preload to maximise traction on the slow speed corners and to also provide braking stability through the trickier braking zones on the track.
- A major difference in this setup compared to some of the other high downforce tracks is the damper configuration. To maximise both braking stability and rear roll control mid corner, the rear rebound has been stiffened quite a bit. The front bump damping has also been stiffened with respect to the Laguna setup.
- The preload is on a regular value range that has been used across most of the high downforce fast variants. The ride height however is particularly sensitive around here. It is important to keep it around the current window with the present suspension configuration.
- For quali the dampers have been significantly adjusted to improve the traction out of the first few corners, which tends to get worse when the fuel is removed due to it being a downhill throttle zone.
- The setup at Laguna Seca uses a slightly different approach to Barcelona. The springs on the front and rear are run very soft to increase mechanical grip on the slippery track surface.
- The dampers and bumpstop rates instead have been stiffened to get the rotation back in high speed rotation.
- The differential is quite sensitive around here as it has an impact on the tight high speed corners through the circuit. Consider raising the rear ride height if the preload is increased to match high speed rotation. Generally with the slippery nature of the track and very high preload is not ideal.
- There are no peculiarities in the setup at Kyalami and the setup has a very similar approach and layout to the other high downforce tracks in the pack.
- However there are a few things to keep in mind. The differential preload here is quite powerful in affecting braking stability. With higher fuel loads, a lower preload ensures that the car rotates with enough weight on the front end to prevent locking. The rear is sufficiently loaded with the extra fuel and the open differential does not affect locking. On the contrary, running a higher preload on a heavier tank will cause understeer on entry and start locking the brakes on the rear quite abruptly if the car is turned in too quickly.
- The safe setup on the other hand requires a slightly more locked differential to ensure that the off throttle idle torque pushes the car to understeer into the apex.
- This makes braking much easier. With the rear tyres being less mechanically loaded in this scenario and with a relatively low ride height, the car can be thrown in a bit more aggressively to get a relatively stable first half to the corner. If more rotation post apex is required consider increasing the rear bump damping by 3-5 clicks as per preference.
- A small amount of sliding at slow speed to get rotation is needed to extract pace, but this will hurt the tyres in long runs.
- Rear ARB can help tune this to suit driving style. Safe set utilises softer ARBs to make it more predictable.
- As this track is traction limited in almost all cars, a high rear bumpstop range is utilised to help traction.
- The M4 can run very low wing around here without much compromise to stability, however it needs to run a slightly stiffer front ARB than usual for stability in high speed corners very similar to the approach used at Paul Ricard.
- Contrary to the Paul Ricard setup, a slightly stiffer damping configuration has been required around Monza primarily due to the stability requirement through Ascarri but also in order to not over rotate the car on entry into fast narrow corners like the Lesmos.
- Adding differential preload to the current setup by 1 click shouldn’t cause too much concern, however any more than that and the car will start losing traction on high speed narrow apexes as the inner tyre will lose too much load mid corner.
- The safer setup runs a softer front rebound damping to load the rear tyres quicker out of corners. This makes the car safer out of medium/high speed corners however it will come at the cost of slight understeer. This can once again be fixed with slightly stiffer front toe, thereby making it an overall stiffer setup with a balance similar to the fast variant.
- Softest spring settings have been used to help the high kerbs here make the least impact possible to handling.
- Soft dampers also contribute to this, along with the soft rear bump damper aiding traction, and the front rebound aiding rotation on power.
- Roll bars tuned to help with mid corner rotation.
- High wing and rake setup used as corner speed is more critical than straight line speed on this track.
- Driving tip – Try to avoid use of 2nd gear, as the gap in ratios causes too much instability. Tosa hairpin is the only place where it should be used.
- Safe setup uses slightly less rake and softer rear roll bar along with a stiffer preload, this should increase traction and stability for longer stints, though power-on understeer may be a factor.
- Quali setup uses more aggressive roll bars and dampers, and may also work for races.
- Pads 2 to be used for both quali and race formats, pads 1 too sensitive for practical use in GT4.
- Low downforce setup for maximising top speed, but also improves laptime.
- Shorter, stiff rear bumpstops to reduce high speed understeer and understeer under acceleration.
- High rake used to help dynamic responsiveness coming down the mountain section.
- Safe setup uses higher wing, less rake, and stiffer front spring. This adds more stability but also more precision to help navigate the tighter sections.
- The long right at the end of the lap is tricky as the car understeers through here despite what you throw at it. ARBs, diff and rear bumpstops are set to help the car through here.
- Diff can be a useful fine tuning tool for this corner as well as general entry to mid corner off throttle balance.
- A lower rear ride height is used to help with high speed entry and traction but can be tuned up or down to suit. The rear ARB can also be tuned down to make the car more stable on entry and mid corner in conjunction with the rear ride height.
- You can fine tune the rear bumpstop range for on throttle rotation to suit driving style and fuel load.
- Oulton Park uses a different approach compared to other tracks. The car runs a reasonable stiff spring configuration to maintain aero stability in and out of corners. Due to the varying elevation and different angles at which braking is done at different points on the track, the stiff spring maintains pitch stability.
- The preload is run quite low however in order to optimise rotation into corners. To maximise slow speed grip while using a stiff spring combination, very soft rear bump damping is used. The front rebound has also been kept quite stiff to prevent understeer on high speed corners.
- Despite being quite a bumpy track and using stiff springs, a highly negative toe combination works well here.
- The differential is run quite low for this track is the major difference between the first iteration of the track (01 version) released mid 2022.
- Tests were done with the front bump damping to maximise entry response, given the soft front suspension has been used to increase high speed rotation on the very narrow sector 3.
- Rear dampers have also been stiffened firstly to increase the high speed rotation/entry stability in the first corner and also to compliment the bumpstop changes which were done to improve kerb stability through the chicane.
- The front bumpstop range is run a bit higher than the previous setup but not quite as high as some of the other tracks in the current update process. For the current damper compromise, this bumpstop range and rate worked best to ensure that the car has optimal performance through aero sections as well as the chicane (due to lack of high speed damper settings, these compromises are often seen in the other tracks as well, in order to optimise kerb impacts.
- In the safe setup, the rear rebound was increased by 4 clicks which made the car much safer on corner entries whilst still maintaining similar balance for the most part on the corner exits. The stiffer rebound of course adds a bit more roll stiffness with the inside tyre being kept loaded, however with the off cambered corners in the final sector this actually works to the advantage of the car. The chicane however will be slightly less responsive and will require a bit of sacrifice on entry speed to get the car to rotate perfectly through the rest of the sequence.
- The setup has been developed to optimise the car through the first sector. With multiple off throttle zones and dynamic direction changes it is important to have enough agility and rake on the car. This is why the rear ride height has been increased (basically been increased to the working range that the other tracks are using in this update of setups) and the front bump damping has been softened a bit.
- In addition to this, the rear bump has been softened for better traction which is needed with the change of the ride height, and a stiffer rebound damping is also used as this is required to prevent the car locking too much on the downhill braking zones.
- The differential preload has also been set quite low similar to the other tracks in this update series for braking stability.
- With a noticeable difference in entry rotation and braking performance through these newer setups, the trend carries into COTA with slightly higher front bumpstop range and generally stiffer bumpstop to accompany the additional movement of the suspension.
- Apart from these changes it lies very much in the same working range as the other high downforce tracks and there are no specific characteristics to look out for on track.
- Med-high wing used to try to balance stability and high speed understeer.
- Rear bumpstops set as trade off between lower speed traction, and not running too wide on fast corner exits.
- Soft springs and medium roll bars to optimise mechanical grip.
- Safe setup uses longer rear bumpstops and slightly lower rake to give better low speed traction and stability for more predictable handling, though it does sacrifice some rotation on power.
- Qualifying setup uses the longer bumpstop range but higher stiffness to prevent understeer at higher speeds.
|Hubert Szymanski/Saiduth Ramesh||Barcelona|
|Hubert Szymanski/Nick Deeley||Hungaroring|
|Amedeo Dekeyser/Rob Taplin||Imola|
|Amedeo Castorino/Saiduth Ramesh||Kyalami|
|Hubert Szymanski/Saiduth Ramesh||Laguna Seca|
|Amedeo Dekeyser/Saiduth Ramesh||Misano|
|Hubert Szymanski/Saiduth Ramesh||Monza|
|Luka Berk/Rob Taplin||Mount Panorama|
|Hubert Szymanski/Nick Deeley||Nurburgring|
|Hubert Szymanski/Rob Taplin||Paul Ricard|
|Amedeo Castorino/Saiduth Ramesh||Spa Francorchamps|
|Amedeo Dekeyser/Rob Taplin||Suzuka|
|Hubert Szymanski/Nick Deeley||Zandvoort|
|Amedeo Dekeyser/Saiduth Ramesh||Zolder|
|Hubert Szymanski/Saiduth Ramesh||Brands Hatch|
|Amedeo Castorino/Saiduth Ramesh||Donington|
|Hubert Szymanski/Saiduth Ramesh||Oulton Park|
|Hubert Szymanski/Nick Deeley||Snetterton|
|Amedeo Dekeyser/Rob Taplin||Silverstone|
|Hubert Szymanski/Saiduth Ramesh||Watkins Glen|
|Luka Berk/Rob Taplin||Indianapolis|
|Aidan Walsingham/Saiduth Ramesh||COTA|