Launch Analysis: McLaren Mercedes MP4-27

As the first real launch of a 2012 F1 car, McLaren have unveiled their MP4-27. In McLaren parlance this was the cars “technical launch” and was carried out at their Technical Centre in Woking, UK.

2011
McLaren had one of the fastest cars in 2011, on its day the MP4-26 was faster than the Red Bull. So the basic approach of the new car did not need to veer too far from direction McLaren had been following. Last year the season was blighted by poor form in pre season testing. Most of the winter tests were interrupted by exhaust problems, as the now near mythical “octopus” exhaust broke after a few laps out on track. This exhaust turned out to be far simpler than the rumours suggested. The exhausts ran sideways across the floor to exit in a longitudinal slit ahead of the rear wheels. This being a complex way to achieve the same sort of fluid skirt that Red Bull achieved with their outer blowing exhaust layout. Once McLaren had followed Red Bulls lead with the exhaust, they were able to catch up. McLaren perhaps even surpassed Red Bull with the exhaust blown diffuser, as the Mercedes Hot Blown engine mappings were superior to the Renault cold blown solutions. Despite the rules trying cap the hot blown benefits as early the Canadian GP, the Silverstone GP weekend showed how much McLaren were lost relative to Red Bull when the restrictions really bit hard.

Philosophy
With a strong car at the end of 2011, the team have learnt about the damage a slow start to the year makes to their championship chances. This year evolution is required, McLaren do not need to find large chunks of time, but do need a car that will perform well at the opening races. Thus we see the refinement of old concepts and little in the way of radical development.
Thus the new car bred from the recent line of McLarens, the family resemblance goes further than the colour scheme. With a low nose and sweeping lines over rounded sidepods are now trademarks of the Woking design team. With the second year of the fixed weight distribution and Pirelli tyres, little needed to be done to the cars basic layout. Running much the same chassis, fuel tank size and gearbox, so the wheelbase is similar to the previous car.
Although the 2012 Pirelli front tyres are a new shape tyre, Paul Hembury from the tyre supplier confirmed to me that the change in the new profile is “not visible to the eye”. So only small optimisations of the front end aero are needed to cope with the change.

The nose-down, tail-up 'Rake' of the car is evident, with as much as 10cm of rear ride height

The studio photos of the car in side profile show off the amount of rake the car is designed to run. This is also a carry over from 2011, as the car could often be seen with a clear 10cm of ride height at the rear axle line. Although managing rake will be harder this year as the greater rear height introduces more leakage into the diffuser from the sides. As yet the teams solution to seal the diffuser are hidden by a simple floor fitted to the launch, although these are removable panels and more complex designs will soon be seen.

With so much to carry over in philosophy and design, what has changed for 2012?

MP4-27 in detail
The stand out points on the MP4-27 are the nose, sidepods and exhaust position.

Firstly the front wing is near identical to the late 2011 wing, so we can expect its general design to carry over, as will the snow plough vane below the nosecone. But the height of the nose at first appears to be at odds with the 2012 rules on a maximum 55cm height for the front of the nose.

Looking closer at McLarens chassis in side profile its clear the family history of low noses has helped here. The dashboard bulkhead is may be just 3cm higher than the cockpit padding (which is 55cm high), the chassis top then curves downwards towards the front wheels. By the point of the front (A-A) bulkhead the top is lower than 55cm, may be as low as 5cm below the maximum height. When compared to the maximum heights (the dotted line on the drawing), its clear this is a very low nose overall.

The snow plough vane under the nose might be part of the secret to a low nose

This creates less space under the raised nose, but the teams snow plough device under the nose works aggressively as a turning vane, so perhaps the team don’t need the higher chassis to get the correct airflow to the sidepods leading edge. McLaren also find the lower nose provides the classic vehicle dynamics benefits of a low CofG and a less extreme front suspension geometry. This trade off works for McLaren and goes to prove not everything in F1 has to be a compromise in search of aero advantage.

Unique drillings between the rim and spokes of the wheel aid brake cooling, the ring fairing is missing on the launch car.

Although details around the front end will change, the wheels are typically a design chosen to last for the whole season. This year the McLaren Enkei wheels sport a novel set of drillings to aid brake cooling. The usual spokes formed into the wheel between the hub and the rim, stop short and a radial set of holes are made near the rim. Although not present of the launch car, there will be a dish shaped fairing added to small pegs formed into the wheel to aid the airflow out of the wheel.

The high rectangular inlet and large undercut set the car apart from the "U" pods of the 2011

In 2011 McLaren were not afraid to try a radical sidepod set up, This was the “U” shaped sidepod, with the angled inlet shape creating channel in the upper section of sidepod (About the MP4-26 “U” shaped sidepods).  This year the team have adopted more typical sidepod format, with high\wide sidepod inlets and steep undercut beneath. I got to ask Tim Goss about this:

ScarbsF1: Can you tell us about why the concept’s changed, why you don’t feel that was a benefit this year?
Tim Goss: Last year’s U-shaped side-pod worked very well with what we were trying to achieve last year with the exhaust layout, it was all intended at creating more down wash to the rear end, and it performed particularly well last year. This year at a fairly early stage we set about a different approach to both the external and the internal aerodynamics of the car, and then once the exhaust regulations started to become a little bit clearer then it was quite obvious to us that the U-shaped side-pod no longer fitted in with both the internal aerodynamics and some of the external aerodynamics that we pursued early on. So it works, it worked very well last year, but it’s actually just not suited to what we’re trying to achieve this year.”

.

Not extreme like the "U" pod, but the sidepod tops do incline slightly

In frontal profile the high and wide cooling inlet is obvious.  The team have been able to incline the sidepod tops slightly, this isnt quite a “U”pod shape, but is quite distinctive.  At the rear the team have kept the sidepods narrow and slimmed the coke bottle shape in tightly to make the sidepod join the gearbox fairing creating a continuous line of bodywork to the very tail of the car.

the heated air from the radiators passes up over the engine and out of the central tail funnel

As well as the external airflow considerations, McLaren looked the sidepods internal airflow, they wanted a cooling exit on the cars centreline. This would have been compromised with the “U” sidepod, so the more conventional shape was selected. The cooling arrangement is similar to Red Bulls philosophy, the radiators direct their heated airflow upwards and around the engine, this then exits in a tail funnel. The launch car had quite a modest central outlet, but we can expect to see far larger versions used at hot races.

the front upper section of sidepod is switchable for version with cooling outlets

Aiding the tail funnel there are also cooling panels on the upper leading edge of the sidepod, either side of the cockpit padding and various panels arund the rear of the coke bottle shape. Different panels will be used depending the cooling and\or drag demands of the of the track.

Last years more complex roll hoop cooling inlets have been simplified into one below the engine inlet

Other cooling functions are covered by the inlet below the roll hoop. Last years double inlet set up has gone and now a single duct is used. This probably cools both the gearbox and KERS.

Viewed through the rear wing the exhaust bulge is obvious

The other notable aspect of the sidepods are the exhaust bulges. These stick out prominently on the flank of each sidepod. They don’t serve an aerodynamic function themselves, but simply fair-in the final 10cm of exhaust pipe. This final section of exhaust is now strictly controlled by the regulations. Its position must sit within specific area, it must point upwards between 10 – 30 degrees and can point sideways plus or minus ten degrees. McLaren have fixed the exhaust in the lowest most rearwards position possible, the tail pipe then pointing steeply upwards and inwards. From the limited view it would appear to direct the exhaust plume towards the outer span of the rear wing.

This would make a blown rear wing (BRW), the added flow from the exhaust aiding the wing in creating downforce at lower speeds. The exhaust position and fairing also suggests an alternative exhaust tailpipe could be used. Paddy Lowe confirmed that different solutions would be tried in testing. From overhead its clear to see the exhaust could be angled differently to blow over the rear brake ducts fairings to create downforce directly at the wheel.


The gearbox case design is not the shrunken design we saw with Williams in 2011 , the differential is low but not unduly so. The top of the case sitting neatly under the tail funnel. Pull rod suspension remains at the rear of the car, while conventional pushrod is on the front end. Lowe commented that the Lotus brake antidive system was not specifically looked at, but was part ”of a family of solutions” that has been looked at in the past. The engineers feeling that the Lotus system was illegal and hence had not been explored further. They declined to comment of the possibility of an interlinked suspension system.
Behind the gearcase, the rear impact structure is mounted midway between the beam wing and floor, fully exposing both the beam wing and allowing airflow into the central boat tail shape of the diffuser. As the diffuser was covered up, its not clear if there are features to drive airflow into the starter motor hole. A new feature on the beam wing is an upswept centre section, the extra angle of attack in the middle 15cm of the wing having a slot to help keep the airflow attached. The upper rear wing is a new design albeit similar the short chord DRS flap wing, we saw introduced at Suzuka last year. The DRS pod is still mounted atop the rear main plane and its hydraulics fed to it through the rear wing endplates. The flaps junction with the endplates follows recent McLaren practice with a complex set of vents aimed at reducing drag inducing wing tip vortices.
Not much else in terms of structures or mechanical parts were evident at the launch. Lowe did confirm to me that the Mercedes AMG KERS remained packaged under the fuel tank in one assembly. Also adding that there would not be an significant weight loss to the system.  As a significant reduction in weight was made between the 2009 and 2011 season, via the consolidation of the Batteries and Power Electronics into one unit.

Mp3 of the MP4-27 Engine fire up via McLaren

65 thoughts on “Launch Analysis: McLaren Mercedes MP4-27

  1. Is Mclaren’s lower nose philosophy of recent years likely to give them a meaningful advantage due to the greater experience, or will it be easy enough for the other teams to come up with an equally effective solution.

  2. Great write up Craig. I know this isn’t strictly relevant and is last years tech but could you just give a quick diagram of one of the Exhaust solutions they ran on the MP4-26 in pre-season? It was bugging me for a year how the exhausts doubled back on themselves in the sidepod and where they ended up.

  3. How on Earth are you not employed full-time to cover the technical aspects of Formula One? It’s more than just a little ironic that easily the best coverage available of the key elements used by F1 to bill itself as “the pinnacle of motor sport” is provided by an “amateur”?

  4. Thank you Craig. Best review of the MP4-27 I’ve read. Are you able to give us your impressions of the developemnt between the 26 and 27? There was some criticism of the RB7 last year that it looked too evolutionary and “not radical” – but it obviously proved to be a formidable car. Clearly the mp4-27 is more evolutionary than recent McLaren’s have been. Having seen it and the team – you sense a confidence in the design?


    • doesnt seem to be an exit. which leads me to ask, how does air go through the radiator? where is the outlet? as air obviously goes through, and this diagram shows no clear exit, and both these pictures don’t show an exit.

  5. great write up Craig. It would be great if you could in a future article tackle the different philosophy of the low nose vs the high nose.

  6. Craig,

    In your opinion, which exhaust solution will be the most effective? Exhaust gases directed over rear wing or through the rear brake ducts. Won’t funnelling the gases through the wheel be better as this by passes the suspension system and effects the pressure on the tyre directly? Also what do you think the solutions may be for developing downforce or containing aero leakage at the rear? The rear ride height of the Mclaren does not differ greatly from last year as you mentioned and now there’s no blown diffuser.

    Thankyou so much for your analysis. Is there anyway of supporting you from Australia?
    Keep up the great work this will be recognised one day. I tell everyone I know about this site.

    • Hello Brad, if you allow me to pop-in.
      If it was me to choose between the neutral RWB and direct-wheel blowing, I’d go for the second approach.
      The first one should have little effect and gain, whereas the second one is deemed to be more efficient at first sight, the conventional wisdom says.

      I’d think though, that you will lose downforce when off throttle.
      The other disadvantage would be the rear ride height – such setup could be quite sensitive when changes are being made to that parameter.
      I’d love to discuss that.

      • Another small disadvantage of blowing the brake duct area is that it gives you downforce whenever you’re on the throttle, i.e. on the straights as well as the corners. By blowing the underside of the rear wing there’s scope for angling the exhaust so that as speeds increase, the increased airflow “bends” the exhaust plume away from the wing and directs it in the gap between the main wing and the beam wing, so shedding whatever extra downforce it generates at higher speed.

        I guess the disadvantage of this is that it will constantly vary with speed rather than simply switch on and off like an f-duct, so could give you an inconsistent balance

      • Kiril,

        Yes, when you are off throttle the downforce will be lost. This will only occur when you are at the start of the corner at initial turn in. As the car clips the apex the driver will start to accelerate. giving more downforce at the wheels. (if the exhaust is pointed in that direction)

        Last year the teams were maintaining the downforce at the beginning of the corner to the apex. Now with no engine over runs blowing the defuser the designers may be looking at making more downforce at the exit to the corner allowing the driver to accelerate earlier out of the corner.

        Also through fast corners when the driver is on the accelerator the downforce will be at the wheels, this may allow the team to run less rear wing like at Monza. Who knows they may switch between both solutions depending on the track.

  7. I’m not sure the exhaust feeds the main plane of the rear wing. If the airflow was that vertical, the airflow to the wing would be quite a bit disturbed wouldn’t it?

    Wit the air being sucked back in behind the sidepods and pushed around the read wheels, I would think it feeds the lower airfoil and help suck more air from under the car?

  8. Hi Craig,
    Another great write-up as always. Regarding the exhaust position, don’t you think that it’s so far out there, that they will actually point it at the rear tyres / diffuser as opposed to the wing? If they just intended to go for the wing, it would surely have been more tightly packaged to the wasted coke-bottle and centre line. This would also complement the rear tyre warm-up advantage Red Bull appeared to have in 2011.

  9. Nice article Craig. One question about the mclaren. just behind the front wheel there’s a waterdroplet like shape on the underside of the tub. Can someone explain to me what the purpose of this thing is. Is it just a place to put some weight due to the fixed weight distribution or has it a different function. See picture of the mclaren’s rake.

  10. Craig,

    I do not like the way you have been treated during the show.
    It seems that they were afraid of some questions that you might to ask and probably not too meaningful answers they could give

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  12. Great!
    I have a question though, you say “Although managing rake will be harder this year as the greater rear height introduces more leakage into the diffuser from the sides.”
    Is it not the other way around, i mean allowing the air to expand in the upward direction prevent it a little from doing so to the sides ?
    The problem is that with the expansion it looses speed which can not be managed with the exhaust gaz momentum this year.
    I wonder if the purpose of the exhaust plumes management at the rear is not to create directly downforce but to reduce drag which allows to create downforce by other means, steeper flaps etc… a tradeoff so to speak
    The goal would be to prevent the air accumulation near the front of the rear tires i don’t remember how to say that in english, well thanks for the report !

  13. Very nice explenation, the first thign came to my mind as soon as I saw that snail snout like rear exhaust ending was rear wheel blown or adjustable to rear wing blown, very nice touch.

    However looking at the Force India, and the Ferrari this can might be one of the few elegantly designed cars. Wonder what E20 has in store for us, to bring Kimi up to speed this year..

  14. Thx Graig for this.
    Imagine after tests or during season it appears that the nose design from, let’s say, Mc Laren, is the best choice. Is it possible for other teams to copy it regarding the big difference with Ferrari approach for exemple (or vice versa)?
    A technical neophyte-long-time-fan of F1 from Dakar

    • Probably not, as the chassis is homologated at the start of the season; there would be no way to lower the bulkhead to meet the nose.

      • rules come and go steveH

        Chassis are no longer homolgated, they can be changed in-season, providing the new chassis has undergone the relevant crash tests

        so in theory astadiakh yes they could…however I doubt Mclaren spent all that time and money designing their new car and didn’t bother to look at whether a high nose would be more suitable than a low one…so don’t worry tooooo much!

        Mclaren would have studied every available option and permutation possible, then built half scale models which would have all been tested in the wind tunnel. They really do work 24 hours a day.

  15. Pingback: Interesting … Launch Analysis: McLaren Mercedes MP4-27 | Scarbsf1′s Blog « F1Enigma's Insider Notebook

  16. Fantastic analysis as always Scarbs.

    Have I missed something or do the MP4-27 exhaust outlets and surrounding bodywork contravene articles 5.8.3 and 5.8.4?

    ‘The entire circumference of the exit should lie on a single plane
    normal to the tailpipe axis and be located at the rearmost extremity of the last 100mm
    of the tailpipe.’

    • So the opening must be on a single plane perpendicular (normal) to the axis of the (round) tailpipe. I think what you are seeing is that when you cut a plane through a complex surface you don’t necessarily get a circle (think of conic sections). The opening could be planar but appear complex because of the shape of the bodywork it is penetrating. Also, I don’t think there is a requirement that the end of the tailpipe be cut normal to its axis. The opening is certainly located at the last 100 mm of the exhaust.

      • To me, it reads that the rear most extremity of the last 100mm must be a square cut, therefore resulting in a perfectly circular tail pipe. Changing that, with extra bodywork or otherwise, is up for interpritation I guess.

      • First shots from testing appear to suggest that Mclaren have now made the (launch design) exhaust exits legal by removing a section of the shrouding pod. The legal final-100mm pipe section is now visable with the correct cut normal to its axis.

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  20. Thanks for all your great work on this site and TFL too. Given the rake of the car is it allowable ,practical or even viable to stop the leakage into the difusser by using redirected air from the air captured by the sidepods(fresh air not exhaust ) released like an air curtain at the edge of the floor.

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  22. Firstly, great work Craig.

    Secondly, people here seem to be mentioning the exhaust gas implications on rear wing and direct to wheel blowing. What I wondered was that (somewhere previously mentioned) there could be an additional pipe on the internal exhaust that under throttle build up in pressure and when off throttle between turn in and apex could blow the wheel winglets providing some stability on corner entry. Would this be a possible solution? I’m thinking more toward the new Ferrari too which has a very radical rear end.

    Thirdly, does the downforce created by blowing onto the specific wheels effect straight line drag?

    Thanks for the analysis though. Really looking forward to the VJM05 and F2012 ones.

    • Not only exhaust gases come out of an exhaust pipe. People forget that directing the pipes to the wheels can, most obviously melt the tyres, and secondly cover them in a film of not so grippy oil…

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  24. Excellent report Craig – the best thing I have seen on the web!.. anywhere actually!! Much better than paltry reports on BBC and other F1 websites. You’re setting the bar I think.

  25. I noticed that neither the McLaren nor the Ferrari have a support rod for the front of the floor. Is this cosmetic for the launch or something new? I checked launch pictures for the 2011 Ferrari and the rod was present. There is a load test in this area with very minor flex allowed; what gives?

  26. Craig.Newey has just mentioned that RB7 run with righer rear ride height to exploit properly the blown diffuser. As the Mclaren MP4/27 still holds such solution, as you mentioned, is a mystery as the downwash looks smaller with lower nose.

  27. Nice work Craig, looks like McLaren has done there home work. It’s going to be interesting to see if they can keep it legal. The front spitter has it’s sides turned up like it’s a vertical skert and the sidepods outer most hull has another verical skert. With a high rear ride height that brings big air to the rear diffuser under the car. The upwards turned tray? Is that legal?Well if anybody can get it threw they can. The McLaren will be the standard for 2012.

  28. HI Scarbs, I’ve been following you on the flying lap, great job Peter and yourself have been doing, I’ve really enjoyed the week or so

    Can you explain what Mclaren’s channels and Ferrari’s…ducts?…are designed to do and why they need them to do what they want to do

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    • Hold the congratulations! I don’t have a job at Autosport, I simply ran a few articlws for them over the busy launch period. Hopefully it will lead to more stuff, but as of now I havent gomne back the old days of regular updates in Autosport.com.
      I will have a lot more content for the blog over the next few days.

      • Sorry. I do think you will be great in that job. I have followed autosport since the bigining of the internet(do you remember dialup modems) and atlasf1. You will highten the standard. So go for it. Tell them that I will stop paying if they do not include you in the staff.

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  31. Hi! Thanks for providing additional depth to my addiction. A question regarding heated air from the radiators. As gas volume increases with temperature would it be fair to say that the airspeed is increased once it’s heated, disregarding the shape of the funnel. Or would this be off-set by a reduction of the airspeed going into the sidepod, causing drag, due to pressure build up?

    • I beleive many F1 aerodynamicists have gone into the tunnel trying to create thrust from heated radiator flow. AFAIK no one has maaged, so your assumptions are probably correct.

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