Welcome to the BMW M4 GT3 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 CDA4 BMW M4 GT3 setups. Please carry on reading below to see what our team found:
- BMW creates a lot of heat on the left side tires. It’s really important not to overdrive the car in T1 and T2 as it will create the most heat in those 2 corners. Once you get close to 100C the car will start sliding a lot.
- To aid the traction, the rear suspension has been set up really soft and the rake is also quite low. It’s best to gain rotation by softening the front of the car rather than stiffening the rear.
- For more traction in slow speed corners like T2, T3 and T4 you can add more positive toe in the rear.
- You can cut a lot of the apexes in sector 3 and the car will remain very stable but watch out for pressure loss.
- TC is sensitive to how you position the car on corner exit. If you are engaging the TC heavily consider re-evaluating how you take the corner.
- The front bumpstop range can be a good way to tune the pitch and roll of the car for entry to either get more rotation or stability.
- The car is overall quite safe and easy to catch if the rear steps out, the safe setup is designed to help mitigate these issues.
- There are numerous options to tune this car around this track to suit your driving style and weather conditions. It’s a fairly straightforward car to drive with Nurburgring not offering too much of a challenge to the car.
- Front bumpstop range and rate can be used to tune entry rotation quite well.
- Rear ride height is also a good way to tune between aggressive and safe overall rotation.
- The safe setup runs a click higher rear wing than the fast setup, but has the potential to be on pace with the faster set. If you prefer a bit more oversteer in slow speed corners as the compromise, for a better straight line advantage in a racing situation.
- The safe setup is marginally slower on the back straight but it is easier to be consistent with and is an optimal choice for much longer races.
- The setup makes use of running a very soft mechanical combination with stiffer dampers to control the roll of the car. The car has also been optimised to attack the kerbs through the first sector without any trouble.
- Can be tricky to set up here due to the mixture of high speed and low speed corners and the general understeer characteristics of the car.
- ARBs and diff are the preferred options to tune the car balance, particularly through the high speed sections.
- Forcing the car into the corner will make it slide. Be careful of the bumps and despite the kerbs being relatively flat, they can still unsettle the car in some corners if you take too much of the kerb or take the wrong angle over them.
- The ARB configuration needs to be quite stiff for Spa in order to minimise roll through Eau Rouge and to maintain enough response through the direction changes in the second sector.
- Contrasting this, the springs have been set up to be soft to increase grip through the downhill sections and the slow corner exits. In a front engined car such as the M4, the rear end tends to snap quickly out of slow speed corners at the beginning of throttle application since the rear tyres have less vertical load. However if the car is carefully controlled out of slow speed and suddenly loaded late at the apex, the tendency to understeer increases since the front tyres loaded by the engine placement are taxed for grip.
- Therefore on a track such as Spa with many types of corners, there is a stark contrast between roll and pitch settings. The balance has been maintained by making damper adjustments.
- The rear suspension has been set to be quite soft in order to increase compliance through the Spoon corner and also over bumps through the first sector.
- Since the car goes through multiple direction changes uphill, the dampers have had to be tuned to maintain enough load on the front tyres, having used soft rear suspension, in order to improve rotation through the first.
- High wing, high rake setup used due to the almost constant flow of corners.
- Due to the low-grip nature of the surface, alignment changes were used to assist with turn in and traction.
- Springs and roll bars set near to middle-of-the-road settings for a balance of high speed cornering whilst not compromising the ride over the kerbs and bumps and grip in slower corners.
- Low preload used to help with rotation.
- Safe setup uses slightly less rake, lower rear spring, and some minor damper changes.
- Quali setup uses a softer rear spring to help with traction, as this becomes a problem as fuel load is decreased. Minor changes to dampers also to reduce any poor side-effects of the spring change. Cambers also increased.
- High rake, high wing setup for maximum cornering performance.
- Slightly higher than normal ride height to cope with the large kerbs in the chicanes.
- Dampers tuned to minimise instability on takeoff/landing on kerbs.
- Low preload, soft springs and soft roll bars are all used for rotation and road-holding on bumpy surfaces.
- Longer bumpstops used to remove crashy nature of the car over kerbs as best as possible.
- Maximum wing to maximise performance in turns.
- Very soft springs for good mechanical grip especially in the last sector.
- Very low differential preload for good rotation in fast turns such as Turn 3.
- For qualifying, toe on the front was increased to maximise performance.
- In turn 2 you can safely climb over the kerb and pass it, the car will remain stable.
- Exit traction can be a problem. If you are still struggling, consider adding some rear toe or a softer rear arb.
- On the other hand if you want some more front on entry, try adding some front bumpstop range
- Car drives very well otherwise, nothing else to add.
- Very soft rear suspension is necessary to utilise lower TC in Turn 2 and last corner.
- Stiffer arb combo on the safe race set takes away only a bit of rotation, but in return it offers much more stable entry and overall more responsive and predictable car behaviour.
- In the Q setup there is a very stiff front rebound which is the main setting providing extra rotation for a more aggressive qualifying setup.
- For optimal lap time, a slight powerslide is needed out of the T2 (hairpin). In qualifying also short shift into 2nd gear.
- SInce the car doesn’t have a very sharp turn-in, it’s better to brake into the corkscrew in a straight line towards the apex and cut the inside kerb.
- Because of the direction changes and high speed corners here, stiff ARBs are preferred but they can be used to dial general balance to suit.
- The safe set is geared towards giving a wider operating window for kerb usage, allowing more predictable behaviour over them, but it is ultimately slower as you need the rotation from a more aggressive setup approach to extract the lap time.
- Be careful about going too soft with wheel rates and dampers to get more mechanical grip, despite the low speed nature of the track as the car can snap on you, particularly from over driving which the car is sensitive to.
- Chicane can be a tricky corner to get the car set up for. Bumpstops can help here the most and then use toe and ARBs to fine tune the general balance afterwards as the dampers and ride heights are tuned towards the best compromise between the chicane and overall grip and rotation.
- To increase traction in corner exits, it’s best to add positive toe. Raising TC will cost a lot of lap time.
- The bumpstop rates are high to absorb impact when going over the sausage kerb in Ascari exit. Cutting the sausage a lot will actually keep the car more stable compared to just clipping it. BMW is quite bouncy on the exit there but dampers have also been set up to stabilise the car quickly and prevent crashing.
- Parabolica exit requires a bit of patience on throttle. You have to either open up the exit or wait longer before going fully on throttle if you want to follow the tight line.
- When driving with a full tank there is a lot of centrifugal force. Do not try to enter chicanes and Lesmos too sharply or the car will oversteer. You can also counter it by raising the rear rebound slightly.
- Traction and kerbs are the main limitations so the setup is built around those. However, while it can take kerbs quite well, if you go too extreme with bumpstops then they can become an issue. There is some tolerance in the values though to allow fine tuning to suit your driving and room in the front bumpstop range to make it more aggressive should you require that.
- General rotation can be tuned with ARB’s and diff. Rear toe can also be used but has a big effect on traction.
- Valencia setup used as base – this is mainly to pick a starting setup that suits the driving style of the driver making the setup, comfort with the car is a key factor to going fast at Bathurst.
- Lower wing used compared to Valencia due to the long straights.
- Changes to bumpstop length to assist with exit traction in T2 and T4.
- Dampers adjusted slightly for balance during weight shift.
- Preload tweaked for stability off-throttle.
- Safe setup uses lower rear ride height and softer rear ARB to add stability, along with slightly higher rear toe to aid traction.
- Quali setup uses slightly more aggressive toe and camber settings and a softer rear spring.
- Be careful with heavy braking into hairpins. If you start steering too much while still pressing the brake a lot, the wheels can lock up and cause a slide.
- For more low speed grip out of hairpins it’s good to add rear positive toe. Raising the rear bumpstop range also has an impact on grip even though MoTec may not show the bumpstops being activated.
- Setups run the brake bias very low to aid braking performance into hairpins. If you have problems with entry stability it’s probably better to stiffen the rear rebound rather than raise the brake bias.
- Soft front arb helps the car to rotate around the tight hairpins without the need for very deep and accurate trailbraking.
- Be mindful of your steering inputs through the second last corner. It’s easy to put in too much steering and grain the front tires.
- More negative front toe is used to reduce scrubbing of front tires during sharp entries.
- Stiffer wheel rates, softer bumpstops and more bumpstop range all have minor impact on the car clearing the entry kerb in the second chicane. BMW hits the kerb quite hard and there doesn’t seem to be a big time gain over going around it.
- Even single clicks on differential preload are really noticeable during coasting through Island Bend. It can be easily raised or lowered to control the rotation
- TC is quite strong so you need to be aggressive with the throttle to use it to your advantage.
- Q setup has a stiffer rear roll bar to achieve sharper turn-in for the chicanes as well as stiffer front rebound for more grip on the front.
- Soft suspension aids top speed approaching Bus Stop but the springs cannot be run on the minimum rate or that car won’t have enough support in T1 during compression and will understeer. Bit stiffer wheel rates also help keeping the car stable through the chicane.
- Rotation as usual is best to adjust with the front mechanical grip. Changing the front bumpstop range seems to have the least side effects.
- Bumpstop rates are set higher to absorb bigger impacts going over bumps in bus stop.
- On full tank the rear of the car is a bit lazy so it’s better to follow a tight line through the bus stop and avoid big direction changes.
- Increasing the differential and adjusting the pressures was our first step from the baseline.
- Maximum wing is clearly the way to go. However, to increase the rotation in low speed corners we had to increase the rake significantly. The car felt heavy in the front and difficult to rotate.
- To fix that, we experimented with an aggressive change in anti-roll bars, trying to produce more rotation in the corner entry. The ARBs were fine tuned finally to find the correct balance between predictability and rotation. Also higher wheel rate helped with this.
- High camber is highly beneficial for maximum grip at high speed.
- Dampers were tuned to maximise traction and braking, while keeping the car stable on the kerbs.
- For the safe setup, you can decrease the rake more if you feel it is too nervous. It shouldn’t affect the time much. You can go up to 65mm.
- The car is setup to rotate on entries, if you are struggling with oversteer at this point try lowering the front range by 2.
- Rear traction on indy is tricky, therefore a low diff and softer springs are used. A softer rear arb can be used if its still not enough.
- There is a compromise needed between stability with traction and good rotation. Although the easier the car is to drive, the faster it is, albeit within reason.
- However, there are lots of options to fine tune the car through bumpstop ranges, rates and toe to suit driving style.
- If you are having trouble with the car stepping out on downshifts, higher preload will help, particularly in S2 and the last corner.
|Barcelona||Amedeo Castorino||Miguel Jimenez|
|Hungaroring||Luka Berk||Nick Deeley|
|Imola||David Pertile||Nick Deeley|
|Kyalami||David Pertile||Nick Deeley|
|Laguna Seca||Hubert Szymanski|
|Misano||Luka Berk||Nick Deeley|
|Mount Panorama||Amedeo Castorino||Rob Taplin|
|Nurburgring||David Pertile||Nick Deeley|
|Paul Ricard||Chris Hack||Saiduth Ramesh|
|Spa Francorchamps||David Pertile||Saiduth Ramesh|
|Suzuka||Chris Hack||Saiduth Ramesh|
|Zandvoort||Luka Berk||Rob Taplin|
|Zolder||Amedeo Dekeyser||Rob Taplin|
|Brands Hatch||Hubert Szymanski|
|Oulton Park||Hubert Szymanski|
|Silverstone||David Pertile||Nick Deeley|
|Watkins Glen||Hubert Szymanski|
|COTA||Aiden Walsingham||Miguel Jimenez|
|Valencia||Amedeo Castorino||Nick Deeley|