Tyre Wear
Most people will also notice excessive tyre wear after pitting, especially with race tyres. To illustrate this I ran some controlled tests around SSRX. This track produces very little tyre scrub as the turns are long and banked. The tyre degradation was set to Fast for this test.
Toyota Supra (Tuned) Racing Soft (RWD)
Toyota Supra (Tuned) Full Wet (RWD)
Ford Focus ST (Tuned) Full Wet (FWD)
Escudo Pikes Peak Full Wet (4WD)
As you can see a full lap on the pre-pit tyres barely shows any signs of wear. In fact the tyres actually seemed to cool and turn blue. Obviously PD has not implemented any heat generation from sidewall flex. The Supra sustained a constant 450km/h+ without the tyres warming up
What is interesting though is it seems only the driving wheels suffer from excessive wear after the pit stop. Also, there is a constant tyre screeching noise produced after pitting which increases with the speed of the car. You can easily see the tyre wear graphics change as the tyres are ripped apart and screech all the way down the long SSRX straights.
Another by-product of the pitstop it that the camera view shakes much more violently at speed making the horizon to become something of a blur. The cars (especially the Supra) also become much more nervous even around the gentle high banked turns of SSRX.
RPM Changes
Many have also noted cars hitting their rev limiter much earlier in top gear after pitting. While the data logger is now available it is not able to log data from races therefore no direct pre and post pitstop comparison can be made available using this feature (as pitting & tyre changes are only enabled in races).
So first up I ran a series of controlled race tests on SSRX using the Escudo and saved the replay data. I then captured the replays onto a PC and reviewed the video by pausing the car at approximately 8000rpm (as per the tacho needle) and noted the digital speed readout.
The second test was performed using the same car around Daytona this time in free run mode and saving the logged data. I then used the data logger to review the various speed values available while accelerating at 8000rpm.
Based at viewing the replay video playback I noted a significant difference in the recorded speed between the original and pit set of race tyres. While I fell all tyres are affected by this bug the race tyres defiantly seem to be the most problematic. This speed discrepancy between pre and post pit stop is probably a significant factor.
Also the speed of the car seems to increase with the sticker tyres. Initially I thought there was something screwed up with the tyre circumference calculation but upon reviewing the logged data it would seem that PD have implemented some sort of tyre slip calculation depending on whether the car is accelerating or decelerating. To check this I ran a set of controlled test around Daytona using three types of car on Racing Soft tyres.
As you can see the rear driving tyres are slipping slightly under power as they attempt to push the car through the increasing air resistance resulting in a slightly higher wheel speed than the actual speed of the car. But when decelerating the natural engine braking has the opposite effect. In both cases the non-powered wheels match the cars actual speed.
This time its the front driving wheels that are trying to drag the car forward faster than its actual speed. The non-powered rears match the actual speed of the car.
Now all four wheels are attempting to push the car through the air resulting in a slightly higher wheel speed than actual speed. Upon deceleration this is reversed with engine braking.
This animated GIF is taken from gameplay and shows the effect in action.
- Car coasting down to 7000RPM under engine braking
- Hit throttle open and the car jumps 500RPM but only 3km/h
- Car then adds another 500RPM but this time an extra 10km/h
Theory
This tyre slip calculation seems to be at the heart of the problem. Something or some variable is calculated or reset incorrectly during the pit stop routine. This would explain why the tyre screech becomes clearly audible after pitting even in a straight line especially using racing tyres. The massive difference in speeds recorded pre and post pit stop for the racing tyres is quite likely evidence of what is contributing to the flaw.
Every time a player enters the track the bug is not present. As soon as a pit stop is performed the game goes into a bugged state but this is reset by exiting the track (or returning to the lobby) and re-entering the track.
This really should be a simple bug for PD to resolve.
