With a dominant win from Jenson Button in Spa, McLaren has demonstrated their aerodynamic excellence after two successional win. It’s shame that Lewis was crashed out at the beginning of race, leaving us curious about how those two differently set-up cars would actually do in the race. Instead of seeing huge impact from DDRS, what drew attention is actually McLaren’s rear wing adjustment and sidepod airflow conditioner, while their DDRS remains a mystery.
High Downforce vs Low Downforce – Hamilton’s Deleted Tweets
The hottest topic outside the track is definitely Hamilton’s tweets during the weekend. Three of them get delated in two days, among those ghost tweets, the most famous one is the telemetry chart of the two McLaren cars.
McLaren Overlaid Telemetry Chart
It looks a bit completed as there are lots of information merged into one single chart. However, telemetry chart is simple to read when you know which property each line represents. As a common approach of F1 data collection and analysis, a telemetry chart in fact can’t leak out too much serious information. Here is an example of a telemetry chart from 2010, which as an coincidence, is from Lewis Hamilton again. From the top to the bottom, properties plotted on the y-axis are speed, engine revolutions/gear, throttle/brake usage, lateral/longitudinal G force.
Telemetry chart in Bahrain 2010
As we can guess in Lewis’ leaking out chart, the most fluctuated lines represent his speed and Jenson’s. It’s obvious that on straights, Lewis’ car accelerates slower and has lower top speed compared to Jenson’s. Basically Jenson’s car has a low downforce configuration while Lewis get a high downforce one. The picture below combines Lewis’ and Jenson’s car during qualifying – with lower angle of attack, Jenson’s car has reduced downforce and drag, which gives him huge advantage on straights.
Comparison between Jenson’s and Lewis’ Car During Qualifying
However, this doesn’t mean lower downforce is always better on high speed circuits like Spa – downforce at severe corners should always be considered; weather condition has vast impact as well. Nevertheless, McLaren has clearly found the best compromise this weekend for Jenson.
McLaren New Sidepod Airflow Conditioner
The most evident change on MP4-27 in Spa is these airflow conditioners added on top of the sidepods.
McLaren Sidepod Airflow Conditioner
Now the airflow conditioner is connected to the cockpit and runs all the way over the sidepod. It’s expected to further regulating flow around the sidepod and towards the exhaust channel. In Hungry before the summer break, McLaren was using 3 fins on top of the sidepod as vortex generator to improve airflow.
McLaren Sidepod in Hungry
These fins would help smoothing the air by generating controlled vortex flow:
Effect of Vortex Generator
Although vortex generator is a good idea, McLaren seems to find those L-shaped covers over the sidepod working better in controlling the air.
Curiosities – Flexible Front Wing? DDRS?
An interesting picture of McLaren front wing in Spa indicates that it’s flattened during the race:
McLaren Flattened Front Wing
There was suspicion from ScarbsF1 that McLaren use flexible front wing to achieve better aero balance last year in Valencia – McLaren European GP Wing Movement. However although the suspicion was broadly argued, this picture still arise doubts on McLaren tricking on their front wing. Theoretically flexible front wing uses a joint rather than a rigid structure that allows the wing to tilt slightly backwards at high speed. The reduction of angle of attack would reduce front downforce/drag so that it corresponds to the reduction of rear downforce when DRS is activated. Because of the increasing limitation on rear part design, McLaren has actually focused a lot on the front part this season, as reflected in their lifted nosecone earlier this season.
McLaren Nosecone Update
Although the so-called McLaren DDRS was buzzing before the race, there was no clear technical sources leaking out regarding this part. Some says there’re strange bumps on the rear endplates, which could mount in tubes like the Mercedes DDRS. However we still need to wait for more information to make judgement.
Bumps in McLaren Endplate
Besides McLaren, most teams have noticeable updates in Spa. There were more information of Lotus DDRS leaking out though it was not used in this race and is expected to be used in Japan Grand Prix. Also closed cockpit looks favourable in the future considering the huge crash in this race. These topics are hopefully covered in my future posts.