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Speed Trace Analysis – 2017 Chinese Grand Prix Qualifying

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The 2017 F1 season has started off with two teams fighting for race wins in the first three races so far. Most observers of the sport expected Mercedes to figure in the teams fighting for race wins after dominating the previous three seasons, however, Ferrari has surprised many in being the team fighting Mercedes during the early part of this season. The general expectation of Red Bull Racing being the dominant force in the new aerodynamics focused regulations has not yet come to fruition, and this too has been a surprise.

In this post, I’ll present some data I obtained from the telemetry overlays on the onboard videos from Chinese Grand Prix qualifying of the Mercedes, Ferrari, McLaren and Renault cars driven at their ultimate speed during the race weekend. Why only these cars? Simply because I’ve only been able to find usable onboard videos from these cars.

This is an overview of the speed traces (click through on the image caption for a more interactive plot where you can zoom in):

An interactive version of the above chart can be found here

 

For Mercedes, it’s Hamilton’s pole lap. For Ferrari, it’s Vettel’s first hot lap in Q3. Vettel was around 0.3s slower than Hamilton’s pole lap (which was his 2nd hot lap in Q3), and some of that time was lost after he had a fairly big oversteer moment in the exit of turn 13 that compromised his exit speed and on to the 1.2 km long straight.

For McLaren-Honda, it’s Alonso’s Q2 lap that was some 2.7 seconds slower than pole, and for Renault, it’s Hulkenberg’s Q2 lap which was ~1.9 seconds slower than Hamilton. Hulkenberg’s Q3 lap was around 0.05s faster than his Q2 lap, but the video has most of the back straight missing, which has important information about how strong the Renault PU is, so I chose that over his Q3 lap. Unfortunately, the video for Alonso’s lap only starts from turn 7, so the data is only available from then on. Scroll to the end of the post for a description of the methods I used to extract the data.

First, let’s look at how the cars behave in the entry, apex and exit of some corners of interest.

Turns 1 – 4

turn1_4

Vettel had the fastest 1st sector time in qualifying, and it’s possible that he gained all of that in these sequence of corners. He brakes later and harder than Hamilton or Hulkenberg initially, but modulates to carrying a lot more speed into the corner and taking a later apex as a result. It was interesting to note that there was a big throttle spike from Vettel in the approach to turn 2, where his speeds reach a maximum of 131 km/h, much higher than anyone else. However, Hamilton and Hulkenberg are less acrobatic in the transition from turn 1 to turn 3, preferring to concentrate on a cleaner and slower apex speed so they can be back on the power earlier in the exit of turn 3 and towards turn 4. The Renault piloted by Hulkenberg is carrying better speed through turns 2 & 3 than Hamilton too.

Turn 6

turn 6

A theme appears to be developing here. Hamilton is again, breaking earlier than the other two drivers, but is earlier back on the power. The minimum speeds from all three cars are evenly matched, however what Hamilton lost on entry, he gains in the exit of this corner as he’s able to maintain that speed difference to the Renault. However, Vettel’s Ferrari appears to be accelerating harder and so is catching up the Mercedes in the run to turn 7.

Turns 7, 8 & 9

turn 7_9

This sequence is quite informative. The trace starts on the approach to turn 7, which is a long apex high speed corner where the minimum speed is maintained for some distance, so the cornering speed will be more car-limited than driver-limited. Alonso makes his appearance here, and the car is clearly matching Renault which is really encouraging, speaking as a McLaren fan. I would suggest that once Honda sort out the teething troubles early in this season, we’d be seeing regular Q3 appearances and points finishes, cementing the position McLaren were in last year at the top of the midfield. This is scant consolation, however, this is F1 and I expect nothing less in terms of the effort to get to the top and be there. Both Mercedes and Ferrari are well matched in turn 7, and this suggests that Ferrari are an equal to Mercedes in terms of peak downforce generated at high speed. McLaren and Renault lag behind at a speed difference of 4-5 km/h.

Hamilton had the fastest sector 2 in qualifying, and these corners make up most of it. It is immediately obvious how much time Hamilton gained in turn 8, where he’s cornering at a speed considerably higher than his nearest rival (Vettel). It is curious why the Ferrari is not more of a match to Mercedes here. Perhaps, the amount of energy going through the tyres in the previous corner gives the non-Mercedes drivers less confidence on the limits of adhesion for turn 8? Perhaps, it’s the driver making a difference here? Without Bottas’ data, it is impossible to know.

The McLaren is performing well in turns 8 & 9, beating Renault in terms of apex speed, however Hulkenberg is braking later than Alonso, in the entry to both corners and losing out in the exit.

Turns 11 – 13

turn 11_13

This is a very important series of corners, for one of the longest straights on the F1 calendar follows and for this reason, it is interesting to look at how different drivers approach this. Predictably, Hamilton brakes earlier than others and takes an earlier exit out of turn 12 and this is mirrored by Alonso, the latter’s minimum speed at the apex of turn 12 is the highest of all. While maximising the exit speed out of turn 12 makes sense for Alonso, given the lack of power from his Honda hybrid engine, it is curious why Hamilton does this given he likely has the most powerful hybrid engine of the F1 field behind him, unless this is part of how he’s driving the W08 or indeed how he generally approaches his driving. I do remember occasions where this has been brought up by other commentators during this hybrid era (I’m not able to find a source, sorry). The most recent occasion was, an youtube analysis by Scott Mansell (of driver61), but sadly, the video was taken down by FOM.

Acceleration and Top speed

straight

This really gives an indication of the pecking order of the power plants of these cars. Despite having the worst exit of the four cars at turn 13 (previous figure), Vettel’s Ferrari quickly out-accelerates the McLaren and Renault early on in the 1.2 km straight. Vettel continues to overhaul the Mercedes all through that straight but strangely drops off towards the end of the straight, whereas the Mercedes continues to accelerate all the way to a top speed of 329 km/h. Could it be that all of the ERS energy in the Ferrari was spent just before the end of the straight? Another thing of note is that the Ferrari engine was revving to ~12000 rpm under full throttle for 6th and 7th gears, and was hitting 327 km/h at around 11700 rpm in 8th, so there is still some head room for the engine and it didn’t sound like it was hitting a limiter.

It was interesting that the McLaren was able to maintain the exit speed differential to Renault until 230 km/h, when the Renault starts to out-accelerate the McLaren and quickly overhauls it at 280 km/h. The Mercedes is clearly the strongest car here, with Ferrari a close second and Renault a little way off. The McLaren-Honda being the worst. It is no wonder that Alonso was left feeling confused in the race as to how quickly cars that seemed a long way behind him, caught up with him on the straights, especially with the McLaren being without DRS.

The fact that the McLaren could accelerate at the same rate as the Renault up to 230 km/h suggests that McLaren are running compromised gearing from 6th (Alonso shifts up to 6th at 230 km/h) to 8th where the Honda engine appears to be revving from 10800 rpm all the way to 12500, significantly higher than any other manufacturer. The problems with vibrations for the Honda power unit has been widely reported, it’s likely that short gearing is a temporary fix for this issue and not allowing the internal combustion engine to spend a considerable period of time in an rpm range where the resonance is most pronounced. One hopes that when they introduce their next engine, this would be solved and McLaren could revert to a more conventional gearing, which would certainly put the Honda engine on a par with the 2017 Renault PU–and this would be a very good baseline to build up on.

Turns 14 – 16

turn 14-16

As we approach the end of the lap, drivers are wary of losing the advantage they’ve built up over the lap, or simply throwing caution to the wind and continue to push the limits as they come up to a big braking zone. Vettel is able to brake 0.1s later than Hamilton (just past the 150m boards), however Hamilton is able to carry more speed at the apex (68 km/h vs 65 km/h), and gets a better exit in the run to the final corner. Of the four cars studied, the McLaren seems to be worst in low-speed corners, with Alonso braking early and missing the apex at turn 14. Unfortunately, the Renault’s telemetry is cut off from here, but the car seems to carry better apex speeds at low speed corners than the McLaren.

The method: I extracted a specific number of frames from each onboard video corresponding to a resolution of 0.12 s per data point and recorded the speeds. The speeds were used to convert the time information to distance. The laps for Vettel, Hamilton and Hulkenberg all start off at an identical point and the differences observed as the lap goes on is due to differences in the individual driver and car performance, as no attempt was made to align the traces after that. Alonso was roughly aligned based on the acceleration point at turn 7. All data is limited by the resolution provided by the FOM telemetry, and driver/car differences of up to 0.12s can be detected from the plots.

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Microbiologist, guitarist and motor sport aficionado.

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