McLaren MP4-26 – “L” shaped sidepods

Airflow passes over the sidepod to the beam wing (yellow), while an undercut still directs flow the sidepod

With a lot of expectation around McLarens new car, the newly unveiled MP4-26 did indeed surprise with its sidepods. Termed “U” shaped by Technical Director Paddy Lowe, as the two “L” shaped individual inlets together form a “U”. As with other design elements on the McLaren these are almost directly opposite to what the rest of the grid is doing.

What the team have done is to shift the inlet for the radiators at the front of the sidepod as far outboard as possible, to allow a freer flow of air to the rear beam wing (the lower element between the tail lamp and the top rear wing). Typically teams place the inlet for the radiators as close inboard a possible, as this airflow is the cleanest and with the most energy. This allows the sidepods to cool efficiently and hence have smaller inlets for less drag. By placing them outboard the vertical inlet catches the turbulent airflow from the front wheel wakes. Its this messy airflow teams try to keep away from the car with the pod fins. While McLaren may have to have a slightly larger inlet to cope with the poorer airflow, the benefit is that the better airflow closer the centre of the car can now be directed at the beam wing. With the double diffuser banned, a larger proportion of rear downforce will have to come the from the rear wing.

Also by creating this shape inlet it means McLaren cannot have the deep undercuts in the sidepods, which other teams use to direct the airflow around the sidepod and over the diffuser. McLaren have still managed to keep an undercut, but this is much smaller and lower, at about the same as the bottom of the raised nose.

Packaging radiators and ducting into this shape is far more complex than a simple inlet. The radiators themselves have a stepped upper edge, the protruding section reaching up inside the higher “L” shape section of sidepod. This makes the duct that directs air from the inlet to the radiator much simpler.

It remains to be seen if this set up works better than conventional undercut sidepods for creating rear downforce. Others team would be able to recreate the McLaren “L” shaped sidepod inlets. Although it would require a significant change the radiators and bodywork, making it a major package upgrade and not a quick test. For those teams that have not already tried this idea in the past, they will certainly being giving it some simulation time over the next few weeks.


38 thoughts on “McLaren MP4-26 – “L” shaped sidepods

  1. Might this mean, that the McLaren will be even more susceptible to loss of downforce from closely following a car? Or will it just be a bit different, as the air is the same, only going over the top instead of under the car.

    • @ BasCB

      You are wrong to think that this McLaren will succeed in producing 2010 level downforce. This could be the worst McLaren since the mp4-19, which at the time was thought to be a radical. But it failed miserably,partly due to insufficient cooling.

  2. A very clear explanation, as always!

    I like how you immediately tackle the obvious practical questions like how does it differ from the other cars from a conceptual perspective, what could the up/downsides of this concept be, and can it be copied.

    Thanks so much!

  3. Is it just me or do the sidepods kind of look like the Ferrari from the 90s (1996 car from memory?)

    Good to see lots of new ideas, well done McLaren.

      • … which was a dog that needed two major updates to become somewhat competitive over the course of the season, IIRC.

        Can’t wait for next week’s tests! Need More Data! 😀

    • Was about to point the same. Thanks scarbs for clarifying that :). It must be remembered that the 1996 Ferrari was a particularly slow car though ;-).

      BTW, any word on where the exhausts of the Mclaren are? The Woking boys had installed plastic engine and exhausts for this launch, isn’t it?

    • The McLaren sidepods, remind me more of the Benetton B195 (that was also a Ligier JS43) – at least if you look at upper half, higher at the outside than in the middle. I wonder if that was designed for the same goal? Wasn’t it a Rory Byrne/Ross Brawn creation?

      • It’s the upright intake and narrow section inside the intake which looks like the F310, the Ferrari tried the create more df over that surface but also had a double floor so this df might be the idea with this concept. I remember when McLaren was also conservative but really like them being inventive over the last two seasons

      • Having looked again at pictures of the 310 you are right, but it still definitely reminds me of the B195 – even if I am alone on that one!

        Agree about the inventiveness – I’m really pleased about the radical ideas coming from all the teams this season, it really excites me (but makes Scarb’s job harder – thanks for all your hard work, we really appreciate it!)

  4. A really impressive interpretation. I’m sure Mclaren still have a few bits and bobs yet to be revealed e.g. blown diffuser and last years ‘new braking system’ that Jensen was running.

    Could the ‘second’ air inlet be used to stall (through tuning) the beam wing through the allowed 50mm slots or is there no stalling allowed at all? I know many teams experimented with f-ducts last year – could this one be ‘choked’ at high speed, causing a presure change which stalls the beam wing? Or do you think that it is just cooling – methinks not.

    Cheers Scarbs – smashing as always.


    • That’s what I was wondering. I’m not sure if the rule changes banned blown rear wings completely, or just ‘driver actuated’ approaches. If a passive approach were still allowed perhaps McLaren have intergrated the ducting (and predefined choking widths, different for each race) inside the bodywork cover of the car so that it cannot be seen from underneath when it is lifted on inside the garage. This might explain the (smoke and mirrors?) charade with the ‘assembly’ of the car and plastic internals…

      • Its definitely an interesting thought, but would the beam wing contribute enough drag to warrant it being “blown”? I suppose McLaren may think so with their side pod and engine cover design.
        I for one think the diffuser looks pretty basic at the moment in comparison to a few other teams, as well as the exhaust system, so I expect both of those to undergo hefty changes before Bahrain. As Scarbs pointed out in a previous update, RBR changed their exhaust to blow through the diffuser on only day two of the Valencia test!

  5. It’s amazing the things that come to mind when someone does something unusual on a car. When I saw those sidepods head on the first thing I thought of was the Lancia D50 then I thought of some Formula Ford sidepods. I am sure McLaren didn’t take inspiration from either of those.

  6. Thanks Scarbs

    Can’t wait to see it pounding round the track!

    I watched the launch, bodywork was in much smaller pieces than usual, the front wing was the only thing that needed two people to carry it, interesting.


  7. A FEE would explain a lot and as I cannot see an exhaust anywhere on the media images I reckon it’s there but been hidden. But what magic will it have?

  8. Looking at the regs it’s fairly obvious the need to package the sidepods, coke bottle as tightly as posible to get more performance from the beam wing. What isn’t so obvous are the solutions. McLaren have done a great job but I doubt the advantage is that great in isolation and the real trick is more holistic intepretation of the entire mmechanical and aerodynamic systems. Still, I’m surprised McLaren chose to reveal even the slightest innovation at this unveiling event

  9. Not sure if anyone has noticed but there appears to be an additional funnel at the mid point of the undercut. It looks to take air inside the sidepod (

    Whats peoples opinions of the innovation on the front wing? The end plates seem to be trying to funnel air towards the centre of the car instead of away from it (like the other teams seem to be doing). It looks to be an attempt to create a void infront of the tyres.

  10. Scarbs, didn’t Ferrari do exactly the same with Schumachers Ferrari in in the late 90’s, increasing the wheel base to improve the rear aero? And that took a long while to sort out and not near ths length. Every car is now running a rear end similar to RBR with the wasp body shape. All the problems RBR had are mainly behind them with the exception of the additional KERS cooling. That has to be a big advantage along with having a deign in the RBR5 which was very efficient in getting comparable downloads without a DDD.

  11. Just found your site today. I’m sharing it with followers of the new USGP outside of Austin Texas. Friends of Formula 1 Austin Texas on Facebook and Linkedin. We have alot to learn…

  12. Hi Scarbs,
    Great blog!

    For those who mention the F310 & B 195, the inside of the pods were not any where near as low. Mclaren have inclined the rads to lower them to create a larger volume for the air to travel through. The 2 others still had ‘full height’ pods….

    I think getting rid of the roundness of the pods is significant, as this would help stop the air spilling laterally down towards the floor, as well as straightening the flow to the lower wing element, which I think is crucial now that the double diffuser are gone….

    I’m still not convinced high energy air is what you want into the radiator inlets. I would think that you want a high static pressure n the rad matrices. I remember making some bargeboards to test on our F3000’s. We didn’t necessary find much time out of them, but we found that they dropped engine temp by 10-15 degress C (overcooling), even being in front of the rad inlets. I would think even being further outbourd from the centreline, that the Mclaren inlets still see relatively undisturbed air.

    And wasn’t the MP 4/19’s problems notso much cooling, but rather insufficient oil pump scavenging, because the the engine was lowered so much that the sump was too shallow?

    Keeps up the great work,


  13. I thought the larger sidepods was to channel air directly at the rear diffuser, but in your drawing the airflow is going around and under the sidepods.

  14. htbox/
    on the foto i see an exhaust pipe between the lover wishbone and a gurney flap of the diffuser. best seen on the left side just next to the tire. but no opening. It might be possible that the exhaust opens in the diffuser under the car, so fueling the diffuser air stream.
    when looking at the diffuser of the mclaren it has fewer strakes than the diffusers of other teams, especially in the middle part of the diffuser. which might be a clue to an exhaust driven diffuser, improving its efficiency

    on another foto of the backside of the mclaren. htbox/ Might it be possible that the exhaust is next to the stater-hole. just next to the wide part where the starter-hole is located. it might be an optical illusion but on either side i see something round which looks like a opening of an exhaust.

  15. I think this is the reason why the McLaren boys are freaking out over the performance of the car this year. Last year, both drivers (particularly Jenson) had complained that they found it impossible to maintain heat in the rear tyres. I think this is why they emplyed this design this season to direct that cleaner air to the rear beam wing (well explained btw), therefore increasing downforce on the rear tyres. But now the Pirelli’s are degrading at a ridiculous rate which they wouldn’t have been able to understand until testing. I think they believed this to be the solution to all their woes, and now they might scrap it?! thoughts?

  16. Pingback: McLaren MP4-26 Launch pictures ( 4th of February) | beckyloria

  17. Pingback: Launch Analysis: McLaren Mercedes MP4-27 | Scarbsf1's Blog

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