“You again? But we shouldn't have seen each other again?”. This verse from a famous song sung by Lucio Battisti comes to our aid and with a very specific purpose: to take note of the return of the snorkel – a tube that brings air from the upper areas of the car to the engine – on the cars that will take part in the Safari Rally, third event of the 2024 WRC.
The event held in the African state of Kenya has returned to the World Rally Championship calendar since 2021 (in 2020 it was canceled due to COVID-19), but since then the snorkel, which you see on the Ford Puma Rally1 Hybrid that we put on the cover, it was an impossible component to use. Until this year.
Yes, because in the previous three years the system involving snorkeling was not considered necessary as the Safari Rally was considered – wrongly – very different from the editions held up until 2002. Once the two return editions had been tackled in the calendar, it was it is clear how the snorkel could really represent a useful system for the cars even in the current version of the African rally.
Furthermore, from this year the Safari returns to its original temporal position, when it always fell on Easter Monday (Easter Monday, ed.). This means in the middle of the rainy season as far as Kenya is concerned. It will be necessary to evaluate the weather forecast, because if the precipitation were to be heavy, riders and teams will be faced with a lot of mud and wading. This is why the snorkel has been allowed again by the WRC regulations.
This year the Safari will take place on exactly the same weekend as it took place in 1994, an edition in which mud was literally the protagonist due to the heavy rains of the period. Furthermore, the Kenyan mud, once solidified, resembles clay, therefore dangerous for all engine systems because it tends to stick to surfaces and does not let them breathe and therefore cool down sufficiently.
In the past several teams lost cars also due to this type of mud, which became one of the protagonists of the race in the editions in which the rain had transformed the surface of the special stages.
In events like these, rally cars must make use of two very important systems to avoid damaging the engine and, at the same time, have the clean air necessary to fuel it. Let's go deeper into these topics, starting from the Water splash system and arriving at the implementation of the snorkel to better deal with the dangers of the Safari.
The Water splash system: this is how it works
Snorkel and Watersplash system of rally cars
Photo by: Andrea Adamo
Starting from the drawing of the Water splash system created by Andrea Adamo, we take into consideration the lowest duct, which represents that of the airbox (the highest one, however, is the snorkel). This is a conventional solution with a flange in the middle of the tube that goes towards the turbo (just after the door, so to speak) in which a panel filter is placed (or a large chamber in which cone filters are located, depending on of the choice made by the engineers).
Before the flange it is possible to notice a window placed on the upper horizontal plane with a door that can be raised or lowered using a lever (inverted “L” shape in the drawing) integral with the panel itself, therefore attached to the component. The lever, and consequently the door, is operated via a cable. This is identified with the name Bowden cable.
What is a Bowden cable and how is it used
The Bowden cable is made with a rather rigid and structural sheath on the outside, while on the inside there is the cable that hooks to the airbox door and is controlled by a lever which, in the past, was operated manually by the navigator in proximity to the fords.
It is a very resistant cable, but it offers the possibility of following curved surfaces to allow you to attach the door and reach inside the passenger compartment and be operated by the lever. In short, articulated enough to follow a route (of course, not unlimited in deviations) and connect two distant components in the vehicle.
Thanks to the Bowden cable, navigators could close the air pipe to the turbo to prevent water, mud and sand from infiltrating the restrictor and damaging the engine and its components.
Today Bowden cables are also used to control the gearbox. They are rigid enough to allow you to change gear either by pulling the lever or pushing it forward, with the same principle of using the opening and closing of the airbox door that we explained earlier.
Alternative solution: pedal closing with electric motor
Not just the Bowden cable. Small electric motors can be used to operate the opening and closing of the airbox flap instead of the cable system.
These electric motors can be operated via a pedal – always from the navigator – and this allows those who read the notes to have both hands free and, possibly, turn the page while closing the airbox using the pedals.
Several co-pilots mark in the notes the points where to operate the door so as not to have to look at the route, concentrating exclusively on dictating the notes to their pilot.
Didier Auriol, Denis Giraudet – Toyota Corolla WRC
Pros and cons of the two systems
Both the Bowden cable and foot pedal systems have advantages and disadvantages. The Bowden cable one, if it is not kept clean at every service and is not treated with WD-40 lubricant, risks becoming hard. But if you seal it well the system is quite safe.
The pedal system allows you not to make movements with your hands or physical effort, but when crossing fords the electric motor could short circuit if water seeped inside it. It is necessary to isolate it very well even if it is probably the system that will be used by the majority of Safari manufacturers also for reasons of practicality, with navigators who, using the pedal system, will be able to have their hands free.
The window used to let water out
Returning to the Water splash system, once the door towards the flange is closed, the water and sand cannot pass and go towards the turbo restrictor, but are disposed of through the window that opens in the upper panel created by closing the door towards the flange.
When the car is in a ford, the driver does not accelerate when passing through it. Once the car is out, the navigator releases the pedal (or the lever that activates the Bowden cable) and the door closes, making the dynamic air intake functional again.
When is the snorkel used and what is it for?
M-Sport Ford World Rally Team Ford Puma Rally1 testing
Photo by: M-Sport
During the Safari Rally, the cars have to face fords, mud and fesh fesh even for very long stretches, so it is not always possible to get air from the front of the car. For this we need an alternative solution and one of the best is to take air from the upper part, i.e. from the roof.
A tube called a snorkel is thus used (the top tube in the drawing we have published in this article). The snorkel, made of carbon but also equipped with silicone rubber joints to adapt it to the shape of the car, ensures that the air reaches the engine from the highest part of the vehicle. This allows cleaner air to be brought to the engine.
The snorkel works together with the watersplash system: the door is closed to block the entry of water, mud and sand towards the engine components, while the snorkel – positioned so as to exploit the closure of the door, guarantees clean air towards the turbo ( which exploits its suction to bring it inside).
At this point the air intake is no longer dynamic as it does not take pressure from a high point. You will have less dynamic air, but the suction of the turbo still ensures that clean air reaches the engine from the roof. In this way the efficiency of the air intake is lower, but it allows in a moment of low speed – the cars certainly don't go fast in the fords and in the fesh fesh – to be able to cross critical points without damaging the engine and continue the race.
The snorkel is mainly used in those situations, the most difficult ones involving rallies such as the Safari, especially in the rainy season. At present it is impossible to predict what conditions drivers and teams will find in Kenya in a couple of weeks, but Hyundai, Toyota and M-Sport have all carried out tests with snorkels implemented on the cars. In short, better to prevent than to try to cure when it might be too late…
#WRC #Rally #Safari #snorkeling #work
