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The development of the 'nostril'


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#1 Muz Bee

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Posted 04 February 2013 - 04:12

Looking at the comments on the new video clip released to commemorate 50 years of McLaren Racing I pondered the development of the nostril in automotive design.

I heard the story of Bruce's discovery of the negative pressure on the front body panel behind the radiator from a McLaren teamster years ago. The car was one of the M1 series of sportscars and a letterbox vent resulted which found it's way into the M6 and M8 CanAm cars. In F1 the triangular "nostril" appeared on the uncompetitive 1966 McLarens powered by Indy Ford V8 and Serrenisima engines. They seemed to have disappeared for 1967 with the late arriving BRM powered M5 but in 1968 the nostrils became commonplace.

The M7A Cosworth appearing at the beginning of the season had a nose dominated by huge nostril and intriguingly the Ferrari 312 also appeared early with much smaller rear facing vents, even nostrils. Did the fact that Chris Amon was test and race driver for McLaren in early sportcars have anything to do with it. Certainly other F1 teams seemed to have taken a look at what McLaren were up to and before the end of the season, first Lotus then BRM and Honda followed suit with nostrils of their own.

In sports prototype racing Ford's GT40s integrated the nostril, again McLaren had a hand in Ford's racing development and their first LeMans win.

I would be interested to hear from other people with more knowledge on these matters on the logical line of development.

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#2 Simon Hadfield

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Posted 04 February 2013 - 09:11

As big a fan of Bruce's as I am I think he discovered "nostrils" in the same way as Captain Cook discovered Australia (ask the Aboriginal natives) so I commend to the panel the Cegga Maserati of 1961, bodied by Fantuzzi, and I am sure there must be others.

#3 kayemod

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Posted 04 February 2013 - 09:42

Surely with a front-mounted radiator it's just the simplest and most direct way to duct the hot airflow. The modest ground-effect built into CanAm cars from the M6A onwards, was all derived from the shape of the bodywork underneath the car, I think Bruce and Robin Herd were jointly responsible for that idea.

#4 Roger Clark

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Posted 04 February 2013 - 11:50

Didn't one of the Piccolo 250Fs have radiator outlets on the top of the nose? As with all aerodynamic efforts of the 1950s, it's difficult to tell whether they let air in or out. I think they were also bodied by Fantuzzi so there's a link with the Cegga.

#5 f1steveuk

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Posted 04 February 2013 - 12:46

Is there confusion here between inlets and outlets? I thought the outlets were a development of what the aviation industry had and are referred to as NACA ducts, but I may be wrong, I often am!

#6 Tim Murray

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Posted 04 February 2013 - 12:55

Didn't one of the Piccolo 250Fs have radiator outlets on the top of the nose? As with all aerodynamic efforts of the 1950s, it's difficult to tell whether they let air in or out. I think they were also bodied by Fantuzzi so there's a link with the Cegga.

There are several photos of 2533 in Mr McKinney's book showing a duct in the bonnet which looks as though it's there to allow radiator air to escape.

Is there confusion here between inlets and outlets? I thought the outlets were a development of what the aviation industry had and are referred to as NACA ducts, but I may be wrong, I often am!

As I understand it the NACA duct is an inlet device - its curved sides are designed to generate vortices which increase mass flow into the inlet.

#7 mfd

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Posted 04 February 2013 - 12:56

Is there confusion here between inlets and outlets? I thought the outlets were a development of what the aviation industry had and are referred to as NACA ducts, but I may be wrong, I often am!

I was thinking that too! Although you do breathe in & out through nostrils

#8 kayemod

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Posted 04 February 2013 - 13:28

Is there confusion here between inlets and outlets?


On the front end of a rear engined car, surely they could only be outlets. They caused us some problems at SM at the prototype stage, drivers often weren't too keen on them, as if the designer got it wrong, they directed hot radiator air right in the poor guy's face. Aerodynamics as applied to racing car design was often rather hit & miss in those days.


#9 D-Type

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Posted 04 February 2013 - 14:31

Hmmm, well, yes. To quote Stirling Moss in My cars, my career referring to the 1000cc Cooper-JAP::

We added big air scoops each side of the engine to ensure adequate cooling flow, but I remember that when the engine broke behind me one day the smoke came billowing forwards out of these supposed 'intakes' when I was travelling at quite high speed. We really were blundering around in a black art back then.

Admittedly that was 15 years earlier but I don't think aerodynamic knowledge and understanding had progressed much by Bruce's time.

The Ferrari GTO had the well known three openings above the radiator inlet. Were they additional inlets or were they outlets?

#10 Bloggsworth

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Posted 04 February 2013 - 16:21

I was thinking that too! Although you do breathe in & out through nostrils


Depends how hard you were punched on the nose.

NACA ducts are inlet ducts, in fact IIRC one used to be able to get published charts for different sizes and shapes, much as one could with aerofoil sections.

#11 Tony Matthews

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Posted 04 February 2013 - 17:34

Although you do breathe in & out through nostrils

According to one well-known British journalist, Nigel Mansell fans did not.

#12 Muz Bee

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Posted 04 February 2013 - 18:26

The "discovery" of the negative pressure area led to a development whose purpose went beyond just letting hot air out. As was pointed out the so called "NACA ducts" seemed to have as their sole purpose ducting hot air away. As such they tended to be relatively small. The McLaren M7A had a nose which featured two large nostrils and this was mimicked by Lotus in their 1 year old 49 from around September 1968 in North America. BRM and Honda appeared to have joined around the same time.

My speculation concerns the INTENT. I think the McLaren intent can be traced to downforce by way of the events of two years or more earlier, that's my view. The nostrils seem too large to be aimed at cooling. Ferrari's 312 devices were significantly smaller but still quite large for heat expulsion for their time. By September the paddock surely had twigged the true nature of the nostril even if the media of the time which I have sourced paid it no heed.

In any case I would guess the overall downforce generated through the nose, impeded by a radiator, would be small compared to the large front fins, let alone the hideous "biplane" devices.

Edited by Muz Bee, 04 February 2013 - 18:29.


#13 Muz Bee

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Posted 04 February 2013 - 18:41

Admittedly that was 15 years earlier but I don't think aerodynamic knowledge and understanding had progressed much by Bruce's time.


1968 was inarguably the start of the revolution and surely the Chaparral played a part in that movement. Wings were the extrovert use of aerodynamics, underbody airflow was a less obvious application in those early days, but later to have huge importance.


#14 kayemod

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Posted 04 February 2013 - 18:47

The "discovery" of the negative pressure area led to a development whose purpose went beyond just letting hot air out. As was pointed out the so called "NACA ducts" seemed to have as their sole purpose ducting hot air away. As such they tended to be relatively small. The McLaren M7A had a nose which featured two large nostrils and this was mimicked by Lotus in their 1 year old 49 from around September 1968 in North America. BRM and Honda appeared to have joined around the same time.

My speculation concerns the INTENT. I think the McLaren intent can be traced to downforce by way of the events of two years or more earlier, that's my view. The nostrils seem too large to be aimed at cooling. Ferrari's 312 devices were significantly smaller but still quite large for heat expulsion for their time. By September the paddock surely had twigged the true nature of the nostril even if the media of the time which I have sourced paid it no heed.

In any case I would guess the overall downforce generated through the nose, impeded by a radiator, would be small compared to the large front fins, let alone the hideous "biplane" devices.


I really think you're barking up the wrong tree here, as has been correctly stated, NACA ducts are inlets not outlets, they could admit cooling air, but that's all they do. Those "nostrils" on F1 cars like the McLaren M7A may look large from the way they're angled back, but the hot air outlet at the front for the radiators was quite small, trust me, I helped to make the things, and those on the Lotus 49 weren't significantly larger. Since the car's undersides were closed off by bodywork or monocoque, they couldn't possibly have any ground effect function, small amounts of downforce possibly, but definitely not ground effect. Those slots on the upper bodies of McLaren CanAm cars were much the same, there were no inlets on the underside of M6/8 bodies in front of the front axle line, but they did have built-in concavity to produce a fairly small ground effect advantage. No idea where you are, but if you could see any of the cars mentioned, you'd probably understand it all better.


#15 Doug Nye

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Posted 04 February 2013 - 22:52

We always described the M7-type design feature as a top-duct, the word 'nostril' within the racing world having become so identified with the intake design (or rather style) of the 1961 Ferrari 156s and derivative sports cars etc. The McLarens had top-ducted radiators, as did assorted Chaparrals, Fords, Ferraris, the Cegga as already cited and a 250F or two if I recollect correctly. Side-ducted nose radiators, exhausting hot air through the suspension cut outs on each side had been common. The top duct provided a more effective 'lift dumper'.

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#16 mfd

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Posted 04 February 2013 - 23:39

I'm not sure if this was to do with different designers, but the 1966 M2B had the outlets on the top of the nose, but not on the 67 M5A


#17 Muz Bee

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Posted 05 February 2013 - 01:18

As I said "the overall downforce generated through the nose, impeded by a radiator, would be small". My query was to see if connecting dots from M1B body hacking and the top ducting of the M7, has some validity in the way thinking was in those more intuitive, less designer days.

The story goes that Denny Hulme performed an impromptu improvisation on the 1968 M8A to improve airflow from around the guards which was incorporated into the 1969 M8B. This is evident in side view where the semicircular guard opening inherits an angled edge back to the front of the tub proper. The B tub dispensed with a small triangular subframe present on the A. It's said that Denny wandered over to the fire truck at a race meeting and borrowed an axe to perform the modification to the amazement of spectators. Sounds unlikely but my source is well connected. In this instance it would be a case of letting airflow escape which could be producing lift under the body.


Edited by Muz Bee, 05 February 2013 - 01:30.


#18 flatlander48

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Posted 05 February 2013 - 05:18

The Ferrari GTO had the well known three openings above the radiator inlet. Were they additional inlets or were they outlets?


They were blanking covers over inlets. They would remove them in very hot weather.

#19 Roger Clark

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Posted 05 February 2013 - 07:02

The McLaren M7 was, I think, the first Formula 1 to have what appeared to be an attempt at a properly ducted top of the nose exit for radiator air. Previous attempts looked like a hole or two cut into the bodywork in the hope that the air would find its way out. It was usual in those days to fit the oil tank immediately behind the radiator but the M7 moved it to the extreme rear of the car. The Lotus 49 was similarly modified at the same time but without the top ducts.

As was often the case in those days, the Groups 6 and 7 cars were more advanced than Formula 1. The Ford GTs had top ducts from their first races in 1964 and clean looking ones from the time Shelby got involved. The Lola T70 had a particularly clean duct from its first appearance.

As well as the Maserati 2533 mentioned above, one of the second-string works cars (2501?) had a similar duct in 1957. At the same time, one of the V12 cars had NACA ducts, presumably to let air in, in more or less the same position. So was it a high- or low-pressure area? No wonder Frank Costin despaired of Maserati.

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#20 kayemod

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Posted 05 February 2013 - 09:36

The top duct provided a more effective 'lift dumper'.


Doug has summed it up nicely in his last line. Looked at from the side, a late 60s F1 with flat underside and curved upper surfaces was to some extent an aerofoil, ie lower pressure on top than below. Ducting radiator air over the upper body raised air pressure and reduced lift to a small extent where it exited, and that was the main reason for doing it.

That story about Denny using a fire axe to modify a tub, if true, that would have nothing at all to do with airflow, though he could have been trying to straighten a damaged area. The reason the the front corners of the tub were angled back on the M8B was ground clearance. Having a better understanding of airflow than some of their competitors, McLaren ran these cars very low. Some CanAm tracks weren't very smooth, and the front corners on the M8A tubs could ground and get damaged. While it would clearly have some effect on airflow, both good and bad, that was the main reason for sweeping back the front corners of the monocoque and enlarging wheel openings on the M8B.


#21 layabout

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Posted 05 February 2013 - 15:56

As I said "the overall downforce generated through the nose, impeded by a radiator, would be small". My query was to see if connecting dots from M1B body hacking and the top ducting of the M7, has some validity in the way thinking was in those more intuitive, less designer days.

The story goes that Denny Hulme performed an impromptu improvisation on the 1968 M8A to improve airflow from around the guards which was incorporated into the 1969 M8B. This is evident in side view where the semicircular guard opening inherits an angled edge back to the front of the tub proper. The B tub dispensed with a small triangular subframe present on the A. It's said that Denny wandered over to the fire truck at a race meeting and borrowed an axe to perform the modification to the amazement of spectators. Sounds unlikely but my source is well connected. In this instance it would be a case of letting airflow escape which could be producing lift under the body.


I should like to point out that the "hacking" to which you refer was not on any M1 model. It was the Zerex Special that received the hacking, well before the M1s came along.

#22 kayemod

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Posted 05 February 2013 - 16:24

I should like to point out that the "hacking" to which you refer was not on any M1 model. It was the Zerex Special that received the hacking, well before the M1s came along.


And when did Denny drive the Zerex Special, not to mention the M1?. Since that car had a tube frame, it would surely have been rather difficult to 'modify' with an axe.


#23 Wirra

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Posted 05 February 2013 - 20:47

...The Ferrari GTO had the well known three openings above the radiator inlet. Were they additional inlets or were they outlets?

Perhaps less well known; there are six intake openings in the 250 GTOs - three on the bottom. All six and the major opening create an area nearly equal the surface area of the radiator, hence the need to block off the top opening in cooler conditions. Many grasshoppers have become aware of this information but have not lived long enough to pass it on!

http://www.supercars...amp;pID=1005343

Edited by Wirra, 05 February 2013 - 21:00.


#24 lyntonh

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Posted 06 February 2013 - 10:04

Warwick Farm Tasman Meeting 1971

There were six McLaren M10Bs & one M10A.

There were obviously various views as to how the nose should be modified to get the best airflow through the radiators.
Or were they added to improve downforce or trim? The front wings differ as well.
Correct my terminology if it's duff.


Posted Image
M10B Teddy Pilette....as built

Posted Image
M10B Keith Holland....as built (That's a developing stain artifact on the nose cone behind the opening)
Front wing tabs angled very flat

Posted Image
M10B John Cannon...a little wall in front of the opening...front wing extensions

Posted Image
M10B Graeme McRae....a little wall ....further forward...front wing extensions

Posted Image

Posted Image
M10B Frank Matich...a very fancy wall, split & curved, plus fences....front wings turned up at the back

Posted Image
M10B Niel Allen.....a high wall, with the top edge folded forward, & fences back past the opening....front wings turned up at the back and end plates

Posted Image
The photo's junk...but it shows more detail...oh, and the wheel's up

Posted Image
M10A Frank Radisich....a high wall


I started a discussion on almost the same topic on the " Formula 5000 happy days " thread last month.

http://forums.autosp...a...t&p=6095711

It may add to the current discussion, for those unaware of the other thread.......

Edited by lyntonh, 06 February 2013 - 10:06.


#25 flatlander48

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Posted 06 February 2013 - 23:58

I started a discussion on almost the same topic on the " Formula 5000 happy days " thread last month.

http://forums.autosp...a...t&p=6095711

It may add to the current discussion, for those unaware of the other thread.......


Interesting to see a group of similar cars (in theory) at the same point in time. What I noticed was:
  • The shape of the radiator opening has bee changed on some cars. The original nose shape was somewhat flatter on the top than the bottom, like the Radisich car. There is no symmetry top to bottom. On the Allen car, for example, there does appear to be symmetry.
  • The Cannon car appears to have a modified nose section. It seems a bit shorter than the Pilette car and it has a NACA duct on the side. Front wings seem to be adjusted differently, left to right. Lots of other mods too: oil cooler, mirror mounts, roll bar and supports...
  • The McRea has a chin spoiler. Rear upper radius rod repositioned.
  • The Matich car has a dual element rear wing!! However, the elements may be too close together to be effective. Rear upper radius rod repositioned.
Anyway, to answer your question, I don't think any of those spoilers and fences have anything to do with radiator air flow. They are for downforce. If there was a cooling problem, it would have been addressed in some other way, such as larger opening, larger radiator core, etc.

Edited by flatlander48, 07 February 2013 - 00:00.


#26 Muz Bee

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Posted 07 February 2013 - 00:17

And when did Denny drive the Zerex Special, not to mention the M1?. Since that car had a tube frame, it would surely have been rather difficult to 'modify' with an axe.

The mod on the Zerex Soecial was the removal of a small body panel which (I think) gave access to the clutch and brake master cylinders near the footwell. The hacking incident if true would have been in 1968 or early 1969 to his M8A. I had an idea it was at a British meeting so that would indicate early 1969 when it may have already been undergoing ideas for the new M8B model. The M8A (M8A-2) which is almost completely rebuilt in the hands of the Bruce McLaren Trust became the development chassis for the B and then the team's spare for 1969.

I would have thought any chassis would be difficult to modify in the paddock with an axe! :lol: Resourceful Kiwis though!

Edited by Muz Bee, 07 February 2013 - 00:23.


#27 cpbell

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Posted 07 February 2013 - 12:02

Might I gently nudge discussion on to the actual video tribute itself, and ask for opinions? I wasn't born until 10 years after Bruce was killed, whereas many of you will remember him racing and probably watched him. I'd imagine that a few knew him, so, on that basis, did you feel it was respectful and in good taste? I ask as this week's AUTOSPORT arrived this morning, and, apparently, some commentators have criticised the tribute for being in bad taste.

#28 Tony Matthews

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Posted 07 February 2013 - 12:06

Might I gently nudge discussion on to the actual video tribute itself, and ask for opinions? I wasn't born until 10 years after Bruce was killed, whereas many of you will remember him racing and probably watched him. I'd imagine that a few knew him, so, on that basis, did you feel it was respectful and in good taste? I ask as this week's AUTOSPORT arrived this morning, and, apparently, some commentators have criticised the tribute for being in bad taste.

This is probably a more appropriate thread.

http://forums.autosp...howtopic=179581

#29 mfd

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Posted 07 February 2013 - 12:11

This is probably a more appropriate thread.

http://forums.autosp...howtopic=179581


Saved me looking :up: back up the nostrils

#30 AJB

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Posted 07 February 2013 - 12:19

Doug has summed it up nicely in his last line. Looked at from the side, a late 60s F1 with flat underside and curved upper surfaces was to some extent an aerofoil, ie lower pressure on top than below. Ducting radiator air over the upper body raised air pressure and reduced lift to a small extent where it exited, and that was the main reason for doing it.

That story about Denny using a fire axe to modify a tub, if true, that would have nothing at all to do with airflow, though he could have been trying to straighten a damaged area. The reason the the front corners of the tub were angled back on the M8B was ground clearance. Having a better understanding of airflow than some of their competitors, McLaren ran these cars very low. Some CanAm tracks weren't very smooth, and the front corners on the M8A tubs could ground and get damaged. While it would clearly have some effect on airflow, both good and bad, that was the main reason for sweeping back the front corners of the monocoque and enlarging wheel openings on the M8B.

Which may explain why the M8D sometimes raced with GRP "pods" refilling that cutaway area.
Alan

#31 cpbell

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Posted 07 February 2013 - 12:50

This is probably a more appropriate thread.

http://forums.autosp...howtopic=179581



Thanks Tony.

#32 Tmeranda

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Posted 08 February 2013 - 13:37

An interesting application of the nose inlet/exit on the Chaparral 2F
Posted Image
Inside was a throttle which could be controlled by the driver in an on/off method. This vent, when opened, would provide downforce to the nose to help balance the downforce generated by the rear wing on slow corners; but when closed, would reduce drag for top speed.
Posted Image



#33 D-Type

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Posted 08 February 2013 - 14:32

Another example of creative engineering thinking from Chaparral. After all one of the definitions of 'engineering' is 'the application of science'

#34 Macca

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Posted 08 February 2013 - 15:12

People remember McLaren using outlets on an F1 in 1966, but BRM used them in 1965, some chassis having a single outlet and some having two smaller openings.

Posted Image

Paul M

#35 2F-001

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Posted 08 February 2013 - 15:51

re. the Chaparral 2F, mentioned a few posts back...

yes, the flap in the nose is one of the car's less well-known features, but its operation was slightly different to that, and it wasn't creating downforce - rather the opposite.

The 'outlet' indicated on Tmeranda's photograph (nice model, by the way! what brand/scale is it?) is actually the outlet for a front-mounted oil cooler which first appeared at Spa - the cooler being fed, at that stage, from the low, wide aperture at the very front (as was the cockpit cooling). By the Targa Florio, an additional inlet had been added for the cooler (that's the one arrowed as the inlet in the photograph, and you can make out the silver-coloured cooler matrix in the other photo).

The 'flap' in the nose (fed by the low, wide aperture across the lower front of the nose) was always a part of the design. I seemed that, at high speed, the body shape at the front generated a decent amount of downforce (for the time) but of course that was being applied to the sprung body/chassis. In those days, spring rates were tuned more for conventional mechanical grip and handling rather than dealing with huge downloads achieved aerodynamically. At the rear, where the wing was mounted on the wheel uprights, any download was applied to the unsprung parts, the wheels - (just where it belongs really, if you're going to have wings!). Thus the body/chassis is free to move around independently of the wing without compromising spring/wheel rates and without giving driver and drive train a harsh ride.

There are some reports that the team suspected the rear body shape might even be creating a touch of lift at high speed. The problem, then, was that the front suspension became very compressed at max speed and at risk of bottoming out. The 'flap' in the nose, which was hinged at its upper edge, was sprung at a rate to begin to swing backwards under air pressure (above about, I think, 130mph or so, from memory) and allow some air to flow underneath the car - not above the nose to reduce lift as might be supposed - but to actually bring the nose up a little to redress the balance. It was more about redressing the imbalance of the lift/downforce of the body shape than balancing the downforce of the rear wing.

The flap device is discussed briefly in Pete Lyon's Chaparral treatise in 'Cars in profile' and in various articles and interviews in 'Car and driver' and 'Automobile Quarterly, and suchlike.

I don't think they ever tried making the flap driver-operated on the 2F though, did they? The 2E used a kind of 'valve' or butterfly in the nose ducting which was, linked to the wing actuation and that did, as I understand it, act more in the manner of generating downforce, functioning as Tmeranda described - although that was very different car in many ways. The rear wing certainly was driver-actuated though - controlled by the pedal where clutch pedal would have been, had it needed one. I think it was Spa, with its number of long fast corners where they first tried using partial-feathering of the wing with a continuous adjustment rather than just leaving it up or down. The race reports of the time say that at Spa it was eventually left fully down for the race, since they had never run with it in the wet before and it was deemed a bit of an unknown quantity.

An 'edit' on the matter of driver-actuation:

Whilst looking for a picture or diagram to explain the 2F's nose-flap, I reacquainted myself with Pete Lyons' extensive series in 'Vintage Motorsport'. There, it says, in correction to the earlier 'Cars in profile' item, that the flap in the nose of the 2F was, in addition to its air-pressure (and thus speed-related) sprung actuation, rigged to respond to the main wing position - I'd forgotten reading about this! So yes, it was in some circumstances reacting to a driver input. However, as explained above, it is not to be confused with the oil cooler and its ducting - and was not for creating downforce but for raising the nose from a bottoming-out condition at high speed - unlike the installation in the nose of the 2E which wouldn't be reaching such sustained high top speeds.

Edited by 2F-001, 11 February 2013 - 11:16.


#36 Muz Bee

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Posted 12 February 2013 - 23:14

And when did Denny drive the Zerex Special, not to mention the M1?. Since that car had a tube frame, it would surely have been rather difficult to 'modify' with an axe.

I never said that Denny axed a spaceframe early McLaren.

I never said that the nostril became a major evolutionary step in F1 aerodynamics.

I pointed to a sudden major increase in back-ducting of the radiator area starting with the McLaren M7, which was mimicked late in the season by Lotus, BRM and Honda. Maybe overheating suddenly became a problem area with Cosworths and Honda and BRM V12s.

As I said, with a radiator impeding airflow through this zone the total production of downforce would be small compared to the wings and fins of the time. Since you want to continually write stuff into my posts and generally deride me I will bow to your superior intellect Kayemod.

#37 kayemod

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Posted 12 February 2013 - 23:47

As I said, with a radiator impeding airflow through this zone the total production of downforce would be small compared to the wings and fins of the time. Since you want to continually write stuff into my posts and generally deride me I will bow to your superior intellect Kayemod.


Maybe it wasn't you that said it was the Zerex Special that Denny took axe to, but someone did. He couldn't have done anything like that to any any of the M6 or M8 cars "at a meeting" in the UK, they only ever saw daylight in private testing at Goodwood and'Silverstone, that was the only time they appeared in McLaren colours in the UK, as McLaren never raced them here. As I was careful to explain, the "nostrils" were never about "downforce", the aim was only ever to try to reduce lift by exhausting radator air into a low pressure area on the curved upper body, and that's an important distinction. I was there, I worked on these cars, I was responsible for shaping some of the bodywork, and there's absolutely no need to take any of my comments personally, I'm only trying to set the record straight and correct misaprehensions.

#38 Valiant 273 Commando

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Posted 13 February 2013 - 06:00

I think that the initial question posed is a good one. In my opinion the appearance of the “nostril” to let air from the radiator escape does have some significance as it reduces front lift and possibly provides some downward thrust . In simple terms, it was a feature that made the McLaren better than without it. But it does NOT indicate there was a thorough understanding of the overall influence aerodynamics had on vehicle handling and stability. Before 1968 Chaparral appears to be the only team with the insight into these inter-related areas. I feel that the understanding of this “aero-stability” is one of the most overlooked improvements passed down from racing cars to production cars - every vehicle on the road today benefits from this.

Features such as the “nostril” of F1 cars or the Ferrari GTO rear spoiler were thought of as fixes or “band-aids” that made a bad design good. This interview with Jim Hall has more on this -> http://www.insiderac...com/jimhall.htm I had the pleasure of having a similar but much more informal discussion with the gracious Jim Hall in Gasoline Alley at Indy about twenty years ago. When I brought up the idea that he had a better understanding of this than everyone else including the major factories such as Ferrari and Porsche he just had a modest nod of the head.

Also Andrew Fergeson’s entertaining book on the Lotus Indy effort sheds more light on this. He tells of a tire test at Indy in fall of ’67 where the suspension loads were measured and the startling results showed the highest loads stationary in the pits, revealing surprisingly amounts of lift – Colin Chapman just could NOT believe it. I’m sure this started Lotus on the search for downforce which can be seen in the Lotus cars of 1968; the B versoin of the 49 (with said nostrils) and of course the wedge shaped Lotus turbine indycar.


#39 Nigel Beresford

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Posted 13 February 2013 - 08:35

There is a secondary lift reducing effect from improving the flow through the radiator duct via the nostrils.

The flow velocity in a radiator duct is far below that of the free stream (i.e. the car's speed through the air).
Consequently there is a "spillage" effect, like that of water overflowing out of a full bucket with a small hole in its base.

Much of this air passes under the vehicle, creating lift.

The nostrils helped reduce the pressure difference across the air side of the core, improving flow and reducing lift by both adding air to the low pressure region of the flow accelerated up and over the nose of the car, plus (for a given size of entry duct) they reduced the amount of air spilled out of the rad inlet and entrained under the car. This effect would have been more pronounced on the sports cars than the single seaters, but I believe it still applies to both. It is this effect that the "chin spoilers" (used before front wings) counteracted, in addition to inhibiting the tendency of the onset flow to pass under the car.

Edited by Nigel Beresford, 13 February 2013 - 10:19.


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#40 MCS

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Posted 14 February 2013 - 10:23

Great article :up:

#41 kayemod

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Posted 14 February 2013 - 18:49

Great article :up:


Yes, most interesting, but I'd say that McLaren in those days were a lot more clued-up than most of their rivals as far as aerodynamics went. I'm sure they could have done more with the airflow on their CanAm cars, but why would they need to? They were the most professional outfit in the series, and they already had the opposition gasping in their wake, so rather than experiment, they concentrated on other areas. Interesting that Nigel should point out that a radiator impeded airflow to the extent that some incoming air spilled out to the sides and underneath. One of the first full-size jobs I was put in charge of at SM was the M21 formula 2 car, and I can remember how Nigel's dad Don explained to me why they wanted that pronounced lip moulded into the underside of the rad opening. The aim was to limit spillage, they thought it would enable them to get away with a smaller radiator. The car was fairly successful in F2 form, and it later re-appeared little altered as the Trojan T101, the very same rad opening coping with the cooling requirements of a 5 litre V8. The F1 and Indy cars all went to side radiators of course.


#42 Muz Bee

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Posted 15 February 2013 - 00:39

Interesting that Nigel should point out that a radiator impeded airflow to the extent that some incoming air spilled out to the sides and underneath. One of the first full-size jobs I was put in charge of at SM was the M21 formula 2 car, and I can remember how Nigel's dad Don explained to me why they wanted that pronounced lip moulded into the underside of the rad opening.


Rob, were McLaren using "woolies" to analyse airflow at this time? This was before cars being thrust unto wind tunnels wasn't it?

Of course Robin Herd would have brought his aeronautical knowledge to the party in the M7 project which would have had "flow on" effect (no pun intended).


#43 kayemod

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Posted 15 February 2013 - 15:07

Rob, were McLaren using "woolies" to analyse airflow at this time? This was before cars being thrust unto wind tunnels wasn't it?

Of course Robin Herd would have brought his aeronautical knowledge to the party in the M7 project which would have had "flow on" effect (no pun intended).


I think they did, I'm sure I've seen pics of an M6 or M8 with bits of wool taped on, and Bruce clinging grimly onto the rollbar alongside Denny, as he watched them move around in the airflow, but that wouldn't have involved us. I saw 1/8th scale models of the kind that could be used in a wind tunnel, but they didn't consult SM about it, Peter Wright tried to get them to use our wind tunnel but they never did, I think they did some wind tunnel work with the M6, but don't know about the M8. They'd turn up with a full-size plywood replica of the monocoque for us to build onto, and a set of drawings. McLaren always knew exactly what they were after, they'd visit regularly to check on progress, and see how everything looked in the round, but as far as I can remember, very few things were changed. Lola on the other hand were indecision personified, I made several aerodynamic models for testing, but their track results were always behind the orange cars, so it didn't seem to do them much good. Aerodynamicist Peter Wright had an obsession with low-drag straightline speed, doing away with added wings etc. After moving to Lotus, he had a lot of input into the 78 & 79, which were largely Chapman inspired, as a proper racer he knew that any car that was fast into, through and out of corners wasn't going to be passed on the straights, a similar philosophy to McLaren's. I was no longer working there by then, but as soon as I saw the Lotus 80, I could tell that the concept was largely Peter's, aimed at straightline speed with few add-ons, but 'S' shaped sliding skirts, what was he thinking of? It wasn't a total failure though, it added a new term to the F1 lexicon, porpoising.


#44 Tim Murray

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Posted 15 February 2013 - 17:22

Here are a couple of earlier threads on 'the other' Jim Clark. He was involved in styling, among others, the Chevron B16, the Lola T70 Mk3B and the McLaren M6GT:

The other Jim Clark

Jim Clark of Specialised Mouldings

#45 kayemod

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Posted 15 February 2013 - 19:25

Here are a couple of earlier threads on 'the other' Jim Clark. He was involved in styling, among others, the Chevron B16, the Lola T70 Mk3B and the McLaren M6GT:

The other Jim Clark

Jim Clark of Specialised Mouldings


Thanks Tim, you've saved me a job. SM were indeed stylists as well as producing all kinds of complicated things in fibreglass. It's a very skilful process translating scale drawings into three dimensional objects, and what looks OK on paper can often appear very different when you make the thing full size, no matter how accurately those drawings are followed. The threads Tim found explain things in more detail, but as we find so often on TNF, an awful lot of what has appeared in print can be incorrect. The main design credit for the M6A goes to Robin Herd, ably assisted by Gordon Coppuck. Although Bruce would have had a lot of influence, as far as I know, his input would mainly involve looking over those two's shoulders, I don't think he often had a pencil in his hand, and it would have been much the same with the body. Specialised Mouldings' stylist Jim Clark was a genius at translating drawings into good-looking racing car bodies, so although Bruce and others would have been looking over Jim's shoulder, almost all the credit for the purity of line of the end product should go to him. Similarly, an excerpt that I saw from John Starkey's latest book on Lola gives credit for the T70 body to John Frayling and Peter Jackson, SM's MD. In some ways that's true, at least in the sense that Richard Branson flies you across the Atlantic. I think that John did the original drawings for Lola, and Peter ran the company responsible for the bodies, but unlike brother David, he never did anything at all on the shop floor, so as with McLaren's M6A, almost all the credit for the purity of the final form should go to Jim.

I joined SM after Jim left, so although we'd had some contact then, we only really became friendly after he moved to Poole around the same time that I did. I spoke to Jim a month or two ago, and the years haven't been too kind. The poor bugger has been operated on for cancer, though he's more or less OK at the moment. The saddest news though is that he seems to have lost much of his memory, we had a quite friendly and long chat, but he remembered very little of the work he'd done, work colleagues etc, I spent much of the time having to prompt him. It happens to most of us of course, now let me think, what did I come upstairs for?


#46 Nigel Beresford

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Posted 15 February 2013 - 20:20

You will understand my desire to quote Eoin Young on the design of the M6A, as related in his 1971 book on the man, the cars and the team:

"Bruce won the 1967 Can Am title with this first monocoque Group 7 car, designed by a committee consisting of himself, Robin Herd, Don Beresford and Tyler Alexander".

On the subject of aero development methods, Eoin Young quoted Robin Herd:

"We tried wind tunnel work on the early sports cars, and we came up with a whole string of answers, most of which were wrong in terms on the car's performance on the track. In order to obtain realistic data we went down to Goodwood with the M6A and set up a series of pressure tappings over the internal and external surfaces of the car, and I rode as a passenger to record the appropriate readings".

Edited by Nigel Beresford, 15 February 2013 - 20:36.


#47 lyntonh

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Posted 18 February 2013 - 07:58

Posted Image
No nostrils on this McLaren M10A!!
Ron Grable Warwick Farm Esses Tasman Practice 1970

#48 lyntonh

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Posted 18 February 2013 - 07:59

Posted Image
Nostrils of a sort??not a McLaren of course....Derrick Williams Lola T142 Warwick Farm Main Straight Tasman Practice 1970

Edited by lyntonh, 18 February 2013 - 08:01.


#49 David McKinney

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Posted 18 February 2013 - 08:55

No nostrils on this McLaren M10A!!
Ron Grable Warwick Farm Esses Tasman Practice 1970

Isn't there an opening behind the white-painted part of the nose?

Nothing to do with radiator cooling though, as this example had the rad at the rear

#50 GD66

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Posted 18 February 2013 - 09:24

On the side, in fact, David. Rad is mounted out in the breeze adjacent to the roll hoop. Doesn't appear to be an outlet from the nose in these two pics from the Sergent site.

Posted Image

Posted Image

Edited by GD66, 18 February 2013 - 09:25.