CDA4 BMW M4 GT4 Release Notes

Welcome to the BMW M4 GT4 CDA4 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 M4 setups. Please carry on reading below to see what our team found:

Brands Hatch

• As many corners on this track are fast, overall, the car is set up really stiff for both rotation and stability
• To get enough rotation the rear suspension had to be set really stiff. Soft front springs provide good front end grip on entry. 
• Lowering the rear camber helps to optimise surface temps of the tires and give the car better rotation.
• Car is running more rake than usual to overcome understeer but it’s kept as low as possible to retain good traction.
• Soft front suspension doesn’t provide very good handling over bumps so it’s best to cut turn 6 very little. 

Misano 

• Stiff ARBs to increase the response of the car in the change direction.
• The setup is with TC off, but if you struggle you can use TC 1.
• It’s very important to have smooth braking with this car, it’s better to brake earlier and release the brake slowly.  
• Soft springs and bump damping increase the traction of the car.

Nurburgring

• Nurburgring uses the Kyalami setup as a starting point but has a slightly softer rear damper configuration to improve entry and exit compliance due to the narrow nature of the high speed corners around the track.
• In addition to this the front rebound has been increased by quite a margin to maintain enough weight on the front of the car. 
• This track is very demanding on the front tyres and with the GT4’s the potential to understeer is high. The bumpstop ranges have been adjusted to give just enough compliance without causing too much instability into the corners.
• The Kyalami setup can also work around Nurburgring but require a very smooth input to the steering wheel and preemptive braking adjustments, however it is an alternative if you prefer an overall stiffer car.
• The safe setup has a softer roll configuration with a counter adjustment to the dampers to help with rotation nonetheless. 
• The quali setup runs a lower ride height and wing combination in order to get some extra laptimeout of the car, since the delta with only race fuel change is negligible. Different aero tests were done to achieve this combination.

Paul Ricard

• The setup is with tc off, but if you struggle you can use TC 1.
• In T9 especially if you are using TC off it is better to stay in 4th gear, because if you make a downshift in 3rd gear the car is a bit more unstable.
• The car has a big understeer issue, to fix it we put on maximum rake, toe and camber, we put wing 1 to optimise the top speed in the long straight, since it doesn’t compromise the stability of the car.
• It’s very important to have smooth braking with this car, it’s better to brake earlier and release the brake slowly.  

Silverstone

• Brake power is reduced to try to increase predictability under braking.
• High rake with reasonably high wing used to focus on cornering speeds.
• Aggressive roll bar and bumstop settings are also used to aid rotation.
• Safe setup uses softer rear spring, less brake power, and more wing to keep the car as stable as possible.
• Qualifying setup uses some slightly more aggressive bumpstop values to aid rotation along with higher wing for max downforce.

Spa Francorchamps 

• Low wing to maximise straight line speed in the RF Setup, the RS setup uses a little bit higher wing to improve the cars braking performance and make it therefore easier to drive
• RF and Q set use TC 0, it is really hard to control on this track so feel free to use TC on 1
• Dampers adjusted a bit to spa as Zolder was used as a base line.
• Less rear Camber to give the car a bit more mid corner rotation in slo speed corners

Suzuka 

• The current GT4 cars seem to be a bit more roll sensitive in the aero department compared to the 1.8 variant, but also require some extra focus on improving mechanical compliance in slow speed corners. 
• The 1.9 variant for the M4 at Suzuka uses a slightly softer roll configuration compared to the CDA3 release. In addition to this the dampers have been stiffened on the rear end in order to provide enough rotation in the high speed corners of the track. Extra preload with respect to the previous version ensures that the car rotates better post apex in high speed corners such as 130R and the corners at the end of the first sector. 
• The setup uses a slightly lower rear ride height configuration as it works well with the current physics of the vehicle but also runs a higher downforce value than before. 
• The bumpstops and bumpstop ranges have had adjustments made between the safe, fast and Quali setups to suit different pitch requirements which are needed to work with the new mechanical values. 

Zandvoort

• High downforce used as Zanvoort is almost all corners.
• Soft roll bars to maximise mid corner grip.
• Preload adjusted to minimise Inside-Rear wheelspin on corner exit.
• Brake force adjusted to aid predictability on braking and the entry to turns.
• Safe setup uses softer rear springs with some other minor changes to aid traction.

Zolder

• The car has a really big struggle on the brakes, try going up with the wing to improve that a bit. But going up on the wing will also infect the pace of the car
• Front ride height adjusted to get better over curbs
• Go down on the rear bump if you need more traction on throttle
• If the car is too unstable on the entry go down on the front bump stop range

Barcelona 

• Tires start overheating very quickly so the car is set up quite safe to provide good handling throughout a full stint. 
• Rake is kept very low together with high wing to give a lot of grip to the rear tires. Rotation is achieved by setting up the mechanical grip and dampers aggressively. 
• Rear bumpstop range has been set so that it only provides extra rotation for the high speed turns 3 and 9. 
• It’s important to minimise front roll. Making the front arb stiff improves the traction a lot and does not hinder rotation. 
• Safe setup brings easier exit out of tight corners thanks to a bit of positive rear toe. 
• Car has good rotation on power so it’s important to start getting on throttle early instead of coasting in mid corner. 

Donington Park 

• On Donington many corners have long exits so the priority was put on good traction. As the traction control is very strong, low grip would cause a lot of time loss.
• The suspension is set soft but the roll bars are stiff as roll negatively affects the car’s grip
• Rotation is gained from settings that don’t hinder traction. The front springs, front bump and rear rebound damping are set very soft. Also the preload is high to get good rotation on power.
• Good front and rear stiffness balance provides good compliance in the chicane
• Into the old hairpin, getting the downshift into 3rd is quite crucial to slow the car down and get it rotated. 

Laguna Seca

• Maximum wing to use all the downforce of the car.
• Soft springs increase the traction.
• The setup is with tc off, but if you struggle you can use TC 1.
• Car is quite aggressive especially if you downshift from 3rd to 2nd gear, so try not to use the 2nd, for example you can do turn 1 in 3rd gear.

Kyalami

• We’ve used a stiffer ARB combination for Kyalami to maximise response while changing directions in the second sector. 
• Additionally to improve rotation in high speed corners through the first sector the rear bumpstop range is kept quite low. 
• The rear dampers have been optimised to provide enough rear end compliance for the undulations on the track and to to work well with the soft springs that are used. 
• Low downforce does not work very well for the car however the ride height is still slightly lower in general compared to the CDA3 variants as the traction with low rake seems to be better with the current update. 

Hungaroring

• The setup is with tc off, but if you struggle you can use TC 1.
• Max wing to maximize the downforce of the car.
• Stiff spring at the rear to have rotation on throttle.
• When you downshift to 2nd gear the car can give you a snap, so you have to manage that as a driver yourself by downshifting late. 
• Stiff ARBs increase the response of the car in the changes of direction.

Monza

• Minimum wing to optimise high speed.
• Soft rear bump stops and stiff rear dampers to try to reduce the oscillation caused by kerb use.
• Alignment adjusted to try to give sharpness in chicanes and traction on the exits.
• Equalised roll bars to balance rotation with traction, minimum roll bar would give better traction, but too much agility is then lost through the Ascari chicane.
• Safe setup uses a softer rear roll bar and longer bump stops to maximise traction.

Imola

• High Rake, High wing to maximise performance in the many turns and chicanes.
• Long bump stop ranges to give more compliance on the large kerbs.
• Slightly stiffer rear spring to aid rotation, along with stiff roll bars on the rear.
• Very low preload to aid entry rotation and minimise exit oversteer.
• Safe setup uses changes to rear bump stop and springs to gain traction, along with alignment changes.

Mount Panorama

• Low wing and high rake to have a nice top speed and less understeer in the high speed corners.
• Be careful in the entry of the downhill, it’s better to brake before the neckline or the car does a little jump and becomes very unstable.
• Stiff wheel rate on the rear to increase the rotation of the car.
• The setup is with tc off, but if you struggle you can use TC 1.

Snetterton 

• Rear wing was reduced in the race fast setup in order to gain better rotation through fast corners
• This track consists of many traction zones so the rear springs are kept soft and rake low for better grip.
• Preload is set low to get better turn-in into hairpins. It takes away a bit of on-throttle rotation so generally it’s better to go for later entries and straight exits.
• With race fast and quali setups it’s better to avoid inside kerbs as they can cause a slide due to aggressive front toe. 

Oulton Park

• The BMW M4 GT4 car will inherently want to understeer through the tight lap of Oulton Park. While not a perfect car/track combination, the understeer has been managed through reducing the front spring rates to their minimum. 
• To assist the car through both chicanes, the dampers at the front and rear have been softened to make the car more compliant.
• Increasing the front toe allows the car to respond better in the entry phase of the corner, improving turn in, however this can impact tyre wear.

Watkins Glen

• The priority for Watkins is to get enough traction out of the off cambered corners in the second and third sectors of the lap whilst still providing enough rotation through the narrow high speed corners. 
• A relatively high rake with very soft rear damper/spring configurations provide enough traction and compliance through the lap. The stiff rear ARB does not appear to affect off-cambered exit grip due to the current damper configuration, so this stiff value has been used to provide additional rotation at the apex of the corner. 
• The front dampers and bump stops have been adjusted to give enough compliance on kerbs and maintain weight on the front of the car to help with uphill corners.

COTA

• High wing, medium rake used to keep stability in the high speed changes of direction, as the car is quite sensitive to roll-centre changes caused by ride height.
• Dampers tuned to give plenty of pitch to aid entry rotation, alongside low preload and high bumpstop ranges.
• Roll bars spread evenly on the car for better high speed balance with the high load corners.
• Safe setup uses lower rake and changes to alignment and dampers to try to improve traction, though this does reduce some of the agility in turns.
• Quali uses a low fuel version of the safe setup, as it maximises traction which is needed as the rear is now lighter.

Indianapolis

• Soft springs increase the traction, since this track is very tricky in that aspect.
• The setup is with tc off, but if you struggle you can use TC 1.
• A very important thing is be smooth with the brake pedal, don’t overdrive the car.
• Very low bump damping values to maximise the mechanical grip.

Valencia 

• Very soft ARBs and springs maximize the mechanical grip of the car.
• Max wing to increase the stability on power and high rake to give rotation to the car.
• Dampers are tuned to optimise the traction of the car.
• The setup is with tc off, but if you struggle you can use TC 1.

Team List 

Track	Driver/Engineer Combination
	Driver	Engineer
Barcelona	Hubert Szymanski
Hungaroring	Amedeo Castorino
Imola	David Pertile	Rob Taplin
Kyalami	David Pertile	Saiduth Ramesh
Laguna Seca	Amedeo Castorino
Misano	Amedeo Castorino
Monza	David Pertile	Rob Taplin
Mount Panorama	Amedeo Castotino
Nurburgring	David Pertile	Saiduth Ramesh
Paul Ricard	Amedeo Castotino
Spa Francorchamps	Jakob Ostermann
Suzuka	David Pertile	Saiduth Ramesh
Zandvoort	David Pertile	Rob Taplin
Zolder	Jakob Ostermann
Brands Hatch	Hubert Szymanski
Donington	Hubert Szymanski
Oulton Park	Chris Hack	David Skidmore
Snetterton	Hubert Szymanski
Silverstone	Luka Berk	Rob Taplin
Watkins Glen	Amedeo Dekeyser	Saiduth Ramesh
Indianapolis	Amedeo Castorino
COTA	David Pertile	Rob Taplin
Valencia	Amedeo Castotino