McLaren Spa Updates

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.

Source: F1Technical

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.

Source: Sutton Image

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.

Source: F1Technical

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.

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Aerodynamic Components on F1 Car

A F1 car is made of thousands of components and nearly every part need to take aerodynamics into consideration. However, there’re some major aerodynamics components that make huge difference to car aerodynamic performance.

Example of F1 Car Major Components – Exploded View of a BMW

These aero components get mentioned again and again in various F1 technical analysis assuming that people know what they are, but the fact is most people have no idea on those terms! I’m going through some major ones starting from the front of the car to the rear.

Front Wing

The first part we see on the front is definitely the front wing. Being the first means that it’s the first part on the car that interacts with the air, therefore having an important job to determine the under stream flow through the rest of car. The front wing generates 25% to 40% total downforce. Major design modification lies on the endplates and flaps of the wing, aiming to reduce tip vortex and wake of front wheel, which is one of the biggest drag components. In addition, ducts and slots are becoming popular in recent years, as can be seen in Mercedes W duct in 2011 and DDRS in 2012.

Sophisticated Front Wing Flaps and Endplate of MP4-27

Barge Board

This are vertical panels located between the front wheels and sidepods. It deals with the dirty air produced by the front wheels, guiding and smoothing air flow into the sidepod. In recent years’ designs, it may also have the function of feeding more air into the diffuser.

ferrari f2012 side view

Ferrari F2012 Side-view: Barge Board in White

Sidepod

Sidepod is the part alongside the cockpit that accommodates the radiator and engine exhaust. Main Function of Sidepod is to 1) cool down the engine and gearbox; 2) control underbody flow to generate desired downforce. The profile of sidepods are varied significantly on different cars based on different aerodynamics configuration. A memorable design is McLaren L-shaped sidepod on MP4-26 in 2011.

MP4-26 L-shaped Sidepod

Airbox

The opening channel above drivers head that guides fresh and cold air to the cylinder for cooling purpose. Nevertheless, besides the conventional aim of cooling, the air flow through airbox can be utilised to generate more downforce/reduce drag by guiding it later to the desired parts on the rear wing assembly. F duct is a good example making advantage of this air flow. It’s also suspected that the Lotus E20 DDRS/ Super DRS has a tricky design of ‘ear’ inside the airbox.

‘Ear’ Inside Lotus E20 Airbox to Help Guiding the Air

Rear Wing

With the use of F duct and DRS, rear wing is always under spotlight in recent seasons. We’re talking about rear wing assembly here which normally consists of two sets of airfoil. The upper set is the main downforce generator including DRS, while the lower set is known as the beam wing. The whole rear wing sets generate to 30% to 40% total downforce.

Adjustable Rear Flap (DRS)

Flap on the rear wing whose angle of attack can be adjusted by the driver in order to reduce drag. Check out more about DRS here.

F duct

A driver controlled drag reduction system, in which a slot gap is opened on the rear wing flap. This air flow through the gap is able to stall the wing, therefore reducing drag.

Beam Wing

A single element wing at the lower part of the rear wing that helps regulate the air below the upper rear wing sets and improves diffuser performance. As F duct mounted on the upper flap is banned, there is now more aerodynamics consideration taken into the beam wing design. E.g. Lotus DDRS system which utilise beam wing to further reduce drag.

Source: Sutton Image

Lotus E20 Rear Wing Assembly

Gurney Flap

An L-shaped strip along the trailing edge of the wing, commonly on rear wings. With the use of gurney flap, flow separation can be delayed at high angle of attack so that more downforce can be generated. Gurney are used more in wet weather where more grip (downforce) is needed. FIA regulates that Gurneys on the rear wing should not exceed 20mm.

Source: ScarbsF1

Gurney flap along the edge of rear wing

Diffuser

The rear element at the underbody of F1 car close to the floor, from which air exits the car. This is the last components where air interacts with the car. The speed of air flow can significantly influence downforce, whereby the faster the flow exits, the more downforce is generated. Most famous designs in recent years are Brawn GP double diffuser in 2009 and exhaust blown diffuser which many teams used in 2011.

Brawn GP double diffuser

Source: ScarbsF1

Exhaust Blown Diffuser