McLaren Roll Hoop and Cooling Arrangement


McLaren have adopted ideas from other teams with the cooling set up for their MP4-26. With the return of KERS, having to package all the hardware and its cooling requirements is a challenge. McLaren want to reduce the volume within the sidepods for aero benefit, so anything the team can do to resite cooling to other areas of the car will be an advantage. Thus the team have developed a car with three inlets around the roll hoop.

Typically all the cars coolers are fitted within the sidepod and fed by air from the sidepods inlet. An F1 car needs to cool the engines water and oil, as well as the gearbox oil and the hydraulic fluid. KERS places an additional load as the MGU and batteries each need to be cooled (via oil and water). With the 2010 move to no refuelling, the fuel tank had to be increased in size. The bigger fuel tanks robbed the sidepod of space and the recent emphasis on airflow to the diffuser\rear wing also creates a demand for smaller sidepods. Over recent years teams have fed the gearbox and hydraulics coolers above the gearbox and fed via different methods from the roll hoop. Typically this is either a dedicated inlet (as per the Williams FW32, Force India VJM03) or by splitting the main inlet snorkel above the drivers head (Ferrari F60-F10).

McLarens 2011 solution is to provide a dedicated feed for each of the different cooling requirements. The engines main coolers reside within the sidepod, fed by the “L” shaped inlets. These vent partly through the rear of the sidepod and partly through the bulge in the tail of the upper engine cover. Equally the engines induction system if fed by the snorkel formed by the roll hoop, which leads into the airbox above the engine.

McLaren MP4-26 airbox inlet flow

Then McLaren feed the gearbox cooler with an inlet moulded behind the roll hoop, this leads down to the cooler behind the airbox and vents via a dedicated tube out the back of the car.

McLaren MP4-26 gearbox cooler flow

Lastly the KERS system is mounted beneath the fuel tank as one component. The entire KERS is cooled by a dedicated cooler mounted behind the roll hoop and under the airbox snorkel. This gets fed from air passing just above the drivers helmet and under the snorkel. From straight ahead the coolers aluminium matrix can be seen through the hole. Heat rejected from the KERS cooler then vents out the back of the engine cover.

McLaren MP4-26 KERS cooling flow

With all of these inlets McLarens reduced sidepod shape, has lead to some compromises. Which is has been to adversely affect the airflow approaching the centre of the top rear wing. Equally inlets create drag and McLaren have two additional inlets to account for. I doubt the cooling set up is a major differentiator between teams. But the different approaches do create some welcome variances in appearance between the cars.


Those little inlets inside the main ones are for cooling the electronics and hydraulics within the sidepods.  Most teams have inlets positioned just inside the main sidepod inlet.

15 thoughts on “McLaren Roll Hoop and Cooling Arrangement

  1. I have always thought that a good way to advance vehicle technology that have relevance to road vehicles, would be to restrict cooling areas, by reducing the width of the sidepods for instance. Cooling will be even more important this year, as you say, clever solutions will surface.

  2. Man, I’ve recently discovered your blog. Your work is awesome! I won’t work for a couple of weeks until I finish reading all your posts! I’ll strongly recommend your site

  3. Great post as ever.

    Love the drawings, are your internal layouts guesses or not? Because they clearly show the packaging requirements of all of the elements of the car, which is neat. Intersting that your exhaust goes where it does.

    I’d give my left leg to be given an f1 car, a toolbox and an expert to talk me through all the cool hyper-tech inside.

    Someone elsewhere pointed out that the sidepod inlets form L and J from the front, which I believe is called serendipity – a happy accident.

    What are the regulations on running variable length induction pipes? Not allowed? Because couldn’t you manage torque vs horsepower by alternating between 2 inlet routes, something I think my car does.

    I’m just a very cynical person and can’t stop looking for the next f-duct or DDD-type innovation 🙂

    • Yes the illustrations of the internals are accurate. The exhaust is the conventional set up used for a lot of the tests (I have a Mac exhausts post coming up!).

      Give us your left leg and I’ll cover an F1 cars innards through out this season.

      Variable inlets are now banned, teams have to homologate a few different inlet trumpets and live with one type per weekend.

      • You have the expertise and possibly the toolbox, but it’s the modern F1 car we’d struggle to find 😉

        I sort of hope Bahrain is cancelled so the first race is a guaranteed cracker, but then I can barely wait for the weekend to get here 🙂

    • If I remember right scarbs, weren’t there teams running an active inlet trumpet that basically extended at low rpm to create higher port velocity for more torque and then got progressively shorter as rpm went up? Or was that motogp? Either way I remember it being banned.

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  8. I wonder if Mclaren are worried about bits of tire clogging the radiator. Their radiators are located in a more vunerable position than other teams.

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