Analysis: McLarens Rear Wing Vapour Trails

Picture courtesy of F1Pulse

A feature of F1 for many years were the vapour trails spiralling off the rear wing tips. This phenomenon largely disappeared a few years ago, but was apparent once more on the rear wings of the McLarens at the recent damp race weekends. So what are these vapour trails and why do McLaren tend to create them more than other teams?

They are in fact more correctly termed ‘vortices’, they are created when the pressure differences are created at the wing tip. As you get high pressure above the wing, low pressure beneath and near ambient pressure to the side of the endplate. When these three flows meet, the higher pressure flow naturally moves towards the low pressure areas. This sets up a tumbling motion and a spiralling flow structure is created. As we know from the aerodynamicists use of vortices to shape and alter flow over other areas of the car, vortices are extremely high energy structures. But with them comes a lot of drag. These wing tip vortices rise upward and outward from the rear wing tips and eventually flatten out behind the car as their energy is dissipated in the free stream flow around the car.
The greater the pressure differential, the greater the vortex created, and this is generally seen better in damp conditions as the water in the air concentrates into the vortex to become visible as a vapour trail.

In years gone by, the site of vortices spiralling from wing tips was seen as a good thing, as the belief that the wing is working hard. To some extent this was correct, with a simple wing the fact that it can create visible vortices did prove the wing was highly loaded. However the drag that it created was less well understood. Since the early 2000’s teams have sought to reduce this pressure difference at the wing tip, in order to reduce drag. Several solutions have been tried to alleviate the pressure differences at the wingtip.

As F1 rear wing have such small aspect ratio’s, (width versus length), there’s little that can be done to reduce this high pressure created towards the endplate without sacrificing total downforce created by the wing. Teams have experimented with twisted wing profiles, reducing the angle of attack of the wing cross section nearer the endplate, to reduce the high pressure created above the flap. But this in turn reduces the downforce created by that section of wing. At tracks where lower downforce is required, teams will still ease the loading of the outer part of the wing, centering the pressure distribution in the middle of the wing.

The other option is to allow the whole span of the wing to be aggressively steep, but use other methods to reduce the pressure difference at the wing tip. Firstly teams such as BAR created a cut-out in the end plate ahead of the flap, this allowed some of the high pressure above the flap to bleed off outside the flap, negating the pressure difference and therefore the strength of the vortex. But this was a fairly blunt solution, so teams created the now-common louvers in the endplate.

This solution directs some of the high pressure air above the wing to the wing tip in a more elegant way. Renault, then latterly Honda and McLaren created a different approach by merging the flap into the endplate, this creates a small gap to direct the high pressure flow to the wing tip.

In the past two seasons reducing this effect has been negated somewhat by other means to reduce the rear wings drag. In 2010 the F-duct allowed the driver to reduce the rear wing downforce and therefore drag. In wet races in 2010 we saw the McLaren’s exit a turn, as speed built up the vortices would appear, then as the driver closed the cockpit control duct the rear wing stalled downforce\drag was instantly reduced. As the driver did this, the vortices also disappeared. This allowed us to see just how soon the F-duct was engaged out of turns.
With the F-duct banned and DRS allowed for 2011, teams are able to adjust the rear wing in qualifying and for overtaking in the race. Depending on the teams qualifying\race strategy, they have redesigned their rear wing to have a different flap size. A small flap, means that the DRS effect is larger, more downforce and drag are shed for more top speed. However the smaller flap means that the rear wing is limited in the downforce it can create, as the sot gap is further back on the wing and separation is likely with aggressive angles of attack. Most teams have followed a design path that errs on this level of DRS effect. As the wing tip is not loaded so highly, there are few vapour trails created.
McLaren however have been almost alone in creating a DRS wing with a large flap, this creates the opposite characteristics of a small flap wing. Less DRS effect is created, but the wing can create a larger amount of downforce when DRS is not activated. Thus their rear wing is steeper and more heavily loaded at the wing tips.

Its for this reason that McLaren tend to be the team in 2011 that create the vapour trails on damp days. McLaren do however have a small flap DRS wing in development. We can expect this to create less trails than their current if it gets to be run in the damp.

 

Book Review: Haynes Red Bull Racing F1 Car

When Red Bull Racing launched their new car for 2011, the event was marked by a very special press pack. The pack was formatted in the style of the well-known Haynes maintenance manuals (PDF). This in itself this was a great book, but almost unnoticed within its pages was the intended publishing of a complete Haynes style workshop manual on the RB6 car.
Now some six months later the Haynes Red Bull Racing F1 Car Owners Workshop Manual (RB6 2010) has been published. As its rare a Technical F1 book is published, not least one with insight into such a current car, I’ve decided to review the book in detail.

Summary
At 180 pages long the book has enough space to cover quite a wide range of topics and it does so. Starting with a background to the team, moving on to the cars technology, to overviews of its design and operation. With its familiar graphical style and hardback format it certainly gives the feel of a proper workshop manual. However this is somewhat skin deep and the pages within, soon revert to a more typical book on F1, although some flashes of the Haynes style do remain.

Steve Rendle is credited as the writer of the book and Red Bull Racing themselves have allowed close up photography of the car and its parts, as well as providing a lot of CAD images.
But clearly a lot of editing has been carried out by Red Bull Racing and the book falls short of its presentation as a manual for the RB6. Despite its confusing title, the book is probably better described as a summary of contemporary F1 technology from the past 3 years.
As the last in depth technical F1 book was the heavy weight title from Peter Wright showcasing Ferraris F1 technology from 2000, this remains a useful source of recent F1 technology.
This places the books target audience, somewhere between the complete novice and those already of a more technical mindset.

Anatomy

With forewords by Christian Horner and Adrian Newey, the opening 21 pages are a background to the team and detail of the 2010 season that brought RBR the championships. Then starts the core 100 page chapter on the cars anatomy, which opens with a pseudo cutaway of the car showing a CAD rendering of its internals.

Firstly the monocoques design and manufacture is covered, with images of the tubs moulds being laid up and CAD images of the RB4 (2008) chassis and its fuel tank location. Although little is made of the fuel tank design.
Moving on to aerodynamics, the text takes a simplistic approach to explaining aero, but there is an interesting illustration of the cars downforce distribution front to rear. This does highlight the downforce created by the wings and diffuser, but also the kick in downforce at the leading edge of the floor, but this is not adequately explained in the text. Mention is made of the front wing and the flexing that RBR deny, this is explained with a simple illustration showing the deflection test. The driver adjustable front flap, which was legal during 2009-2010 seasons, is explained, in particular that the wing was hydraulically actuated. When I understood that in 2009, only Toyota used a hydraulic mechanism over the electric motor system used by all other teams. In trying to explain the nose cone, the text and an illustration show a high nose and low nose configuration, but does not remark why one is beneficial over the other.

This section also covers very brief summaries of bargeboards, sidepods and the floor. Some nice close up photos of these parts included, but again with little explanation. An illustration at this point highlights the other FIA deflection test altered in 2010, which was aimed at Red Bulls alleged flexing T-Tray splitter. In this section the text cites Ferraris sprung floor of 2007, but not the allegation that RBR’s was flexing in 2010. A further simple graphic illustrates the venturi effect of the floor and diffuser, and then the text goes into simple explanations of both the double diffuser and the exhaust blown diffuser.
Having been one of the technical innovations of 2010 and since banned, the book is able to cover the F-Duct is some detail. A complete CAD render of the ducting is provided on page 53; this shows an additional inlet to the drivers control duct that was never visible on the car. This extra duct served the same function as the nose mounted scoop on the McLaren that introduced the F-Duct to F1.
Thus with aerodynamics covered in some 23 pages, the text moves onto suspension and the expectation of detail on the RB5-6’s trademark pullrod rear suspension. After a summary of the purpose of an F1 cars suspension, Pages 58-59 have some fantastic CAD renderings of front suspension, uprights and hub layouts. However the rear suspension rendering stops short at the pull rod and no rocker, spring, damper layouts are detailed. Hardly a secret item, so lacking this detail is let down for a book announced as an RB6 workshop manual. A lesser point, but also highlighting the censorship of some fairly key technical designs, was the lack of any reference to Inerters (Inertia or J-Dampers), The suspension rendering simply pointing to the inerter and calls it the ‘heave spring’, while naming the actual heave spring damper as simply another ‘damper’. Inerters have been in F1 since 2006, predating Renault’s mass damper. Their design and purpose is well documented and shouldn’t be considered something that needs censoring. It’s also this section that fails to showcase the RB5-6 gearbox case. Instead using a pushrod suspended RB4 (2008) gearbox, albeit one made in carbon fibre.
The steering column, rack and track rods are similarly illustrated with CAD images. This usefully shows the articulation in the column, but little of the hydraulic power assistance mechanism. Page 67 starts the section on brakes, again fantastic CAD images supply the visual reference for the upright, brake caliper and brake duct design. As well as a schematic of the brake pedal, master cylinder and brake line layout of the entire car. A nod to more typical Haynes manuals shows the removal of the brake caliper and measure of the Carbon disc\pad. A further CAD image shows the brake bias arrangement with both the pivot at the pedal and the ratchet control in the cockpit for the driver to alter bias.
Although not a RBR component the Renault engine is covered in the next Chapter. An overview of the complex engine rules regarding the design and the specification freeze kicks off this section and cites the tolerances and compression ratio for a typical F1 engine. Pneumatic valves, for along time an F1-only technology are explained, but even I failed to understand the schematic illustrating these on page 77. Also covered in the engine section is some more detail on the fuel, oil and cooling systems. With useful specifics, like capacity of the oil system at 4 litres and water coolant at 8 litres. Again some nice CAD images illustrate the radiators within the sidepod. Many sections have a yellow highlighted feature column; this sections feature is on the engine start up procedure, one of the mundane, but rarely talked about processes around an F1 car (other features are on the shark fin and brake wear). As KERS wasn’t used up until 2011, this topic is skipped through with a just a short explanation of the system.

Moving rearward to the transmission system, the old RB4 gearbox makes a reappearance. Again this disappoints, as some quite common F1 technology does not get covered. Page88 shows some close up photos of a gear cluster, but this is not a seamless shift gearbox. In fact seamless shift isn’t mentioned, even though it made its RBR debut in 2008, the year of the gearbox showcased in the book. I know many will highlight that this might be a secret technology. But most teams sport a dual gear selector barrel, each selector looking after alternate gears to provide the rapid shift required to be competitive in F1. So I think this is another technology that could be explained but hasn’t been.
Tyres, Wheel and Wheel nuts get a short section, before the text moves onto electronics. A large part of the electronic system on a current F1 car is now standardised by the Single ECU (SECU) and the peripherals that are designed to support it. So this section is unusually detailed in pointing out the hardware and where it’s fitted to the car. From the tiny battery to the critical SECU itself. Other electronic systems are briefly described from the Radio, drivers drink system to the rain light.
Of critical importance to the modern F1 car are hydraulics, which are detailed on p105. As with the other sections, CAD images and some photos of the items themselves explain the hydraulic system, although there isn’t a complete overview of how it all fits together.
Rounding off the anatomy chapter is the section of safety items and the cockpit. The steering wheel and pedals are well illustrated with CAD drawings and keys to the buttons on the wheel itself and on the switch panel inside the cockpit.

While I have pointed that the hardware shown in the anatomy chapter isn’t necessarily of the RB6, what is on show is obviously genuine and recent RBR. So for those not so familiar with the cars constituent parts, there isn’t a better source of this available in print today. Even web resources will fail to have such a comprehensive breakdown of an F1 car.

The Designers view

Moving away from the Haynes format of a workshop manual, the book then moves into a chapter on the cars design, with comments from Adrian Newey. It details the Design Team structure and some of the key individuals are listed. The text then covers the key design parameters; centre of the gravity and the centre of pressure (downforce). Plus the design solutions used to understand them; CFD, Wind Tunnels and other simulation techniques. Each being briefly covered, before similar short sections on testing and development close this chapter.
Although the text makes reference to creating ‘the package’, something Newey excels at. This section doesn’t provide the insight into the overall design philosophy, which one might have hoped for.

The Race Engineers view
Where as the Designers view chapter was limited, the race Engineers section was a little more insightful into the rarely talked about discipline of getting the car to perform on track. The process of setting up the car is covered; from the understanding of the data, to the set up variables that the race engineer can tune; suspension, aero, ballast, gearing brakes and even engine. Usefully the grand prix weekend is broken down onto the key events from scrutineering, to running the car and the post race debrief. Feature columns in this chapter include; Vettels pre race preparation and the countdown to the race start.

The Drivers view
Ending the book is an interview style chapter on the driver’s time in the car, mainly the driver’s perspective from within the cockpit when driving the car on the limit and the mindset for a qualifying lap. A simplistic telemetry trace of a lap around Silverstone is illustrated, although there is little written to explain the traces (brakes, speed and gear), this is accompanied by Mark Webbers breakdown of a lap around the new Silverstone circuit.

In conclusion
When I first got this book, I was constantly asked if it was worth the purchase or if I’d recommend it. If my review is critical at points, it’s mainly because some technology that could have been covered wasn’t. Or, that the content falls short of the books title suggesting it was a manual for the RB6.
Those points aside, I have learnt things from this book. Like details of the F-duct system, the Front Flap Adjuster and a wealth of smaller facts. There isn’t a better book on the contemporary F1 car. In particular the CAD drawings and close-up photos, just simply aren’t in the public domain. From the pictures we got over the race weekends, we never get to see half the hardware and design work that’s pictured in this book. So I’ll keep this book on hand for reference for several seasons to come.

Overall I’d recommend this book to anyone with a technical interest in F1.

Many thanks to Haynes Publishing who have allowed me to use their Images and PDFs to illustrate this article

This book is available from Haynes

McLaren New DRS Rear Wing

McLaren have followed their own strategy on the DRS rear wing this season. In contrast to other teams McLaren have designed their wing for the best Non-DRS Performance, thus when deployed the DRs provides a more modest boost in speed. This Strategy appears to have been reviewed as their new rear wing tested at Silverstone shows.

Already being one of the fastest cars in a straight-line, McLaren perhaps haven’t needed to exploit DRs as much as other teams. Their current wing sports a large flap which due to its geometry flattens less when DTS is deployed. See DRS Geometry. But we have seen that McLaren can deploy their DRS less on Q-laps and despite their KERS and speed, sometimes struggle to pass other cars. SO their new wing exploits more conventional geometry with a shorter chord flap that flattens out more completed to maximise the drag reduction system.

Along with the shorter flap other aspects of the wings design have changed, the slots on the endplate have been made even more shapely and the endplate merged into the flap. These slots have been a feature on F1 rear wings for nearly ten years. They aim to take some of the high pressure air above the wing and direct it out through the endplate at the wing tip. This reduces the pressure differences that create the vortices at the wing tip, these vortices often seen in damps condition create a large amount of drag, reducing them further aids top speed.

Although the slots are so curved it’s hard to detect, but the sections between these slots on upper part of the endplate are directly joined to the flap, thus the flap is remotely mounted, the loads pass through these three narrow section of endplate. This must be quite a structural feat. This design harks back to McLaren’s 2008-209 wings (see below) which mimicked the Renault practice of merging the endplate into the flap. Again the aim of this design was to manage the pressure differences at the wing tip for reduced drag.

Ferrari: Silverstone Upgrade

Silverstone brought Ferrari’s major mid-season upgrade to the F150, which was effectively a complete new rear end package. Their upgrade comprised of new exhausts, rear suspension, engine cover, diffuser and rear wing. While the changing rules and weather conditions made it hard to judge if their win was a result of these changes, it was clear that the car had found new pace in fast turns. This in its self is a sign of improved downforce, one of the aims of the upgrade.
Ferrari have been open throughout the year in stating they lack downforce and struggle to get heat into the tyres. The former issue hurts pace on faster turns, while the latter has the combined effect of lost pace on harder tyres and poor single lap qualifying pace.
Again Ferrari s honesty in saying the car was not aggressive or innovative, was clear from its launch. Red Bull, McLaren and other teams tried new ideas. Not all these created the package to beat Ferrari, but Red Bull and McLaren were well ahead of Ferrari in the aero race early in the season.
It seems Ferrari chose to make the car as soft on its rear tyres as possible; as the original expectation was that the Pirelli rear tyres would degrade more rapidly. Certainly Ferrari have been easy on their tyres, but the flipside of this characteristic is that the car can struggle to get heat into the tyres. This is why their pace at Barcelona on the hard tyre was so poor and why they struggle to get the pace on a single flying lap qualifying run.

So with this Silverstone package these areas were addressed and the initial signs are the car has improved.

Firstly the rear wing was all new, aerodynamically, structurally and with its DRS operation. Their new rear wing no longer used a central pylon to support the upper wing and house the DRS actuator. This clears up the underside of the wing from obstructions; this was probably not to reduce the minimal amount of drag created by the support, but more to removes its turbulence from the underside of the wing. Perhaps this will aid the reattachment of the air flow when the DRS closes the flap. Instead the DRS actuator is inside a small pod above the wing, where it will less affect the airflow. Cabling and hydraulic lines to the actuator route inside the wing and endplates. As the pylon has been removed there remains a small section of it on the crash structure ahead of the beam wing (highlighted).

Ferrari have been playing with their rear suspension layout for several races. Visibly the main change appears to be where the upper wishbone meets the upright. This has been moved away from the wheel, by making extending the position of the pickup point on the on the upright. This creates a shorter upper wishbone. The effect of this would be more camber change and lateral scrub as the suspension is compressed. In simple terms as the cargoes down on its suspension the wheel will tilt inwards more and slide across the track surface towards the centre of the car. Both these actions move the tyre about a lot more and help create heat in the tyre. This is how Ferrari have been able to get their tyres into their operating temperature window.

The team ran a new engine cover, with the tail of the sidepods formed in a tighter shape, with some of the cooling accommodated by louvers in the tail of the coke bottle shape.

Lastly the floor and exhaust were subtly changed, with the exhaust pipe shape being altered and the cut away sections of floor being a different profile. Unlike Red Bull, Ferrari have not gone very far in aiming exhaust flow under the car. However they have still gone further than the other teams running the outer blown diffuser. The floor in between the tyre and the diffuser is no longer carbon fibre. But instead a plate of titanium, pictures show this flat metal floor is fully exposed and carefully curved to invite some flow to pass under it. Changes in this area no doubt were made with the 10% engine mapping rule in mind, but also as the diffuser itself used a new geometry.
The next series of races with fast turns and harder compound tyres will prove if Ferrari have reversed their cars characteristics and can take the fight to Red Bull for the remaining ten races

10% rule: Full analysis

UPDATE: As with many of these issues arising over a GP weekend, its a rapidly developing story.  The position given to me by the teams ast night, has since changed, as Charlie whiting considered the situation overnight.  For the balance of the British GP, Mercedes engined cars (McLaren, Mercedes GP, Force India) will be able to use their fired-overrun.  As this was pre-agreed with the FIA for reliability reasons.  However Renault Sports request for their larger overrun throttle opening was requested after the event had started.  Thus Chalrie Whiting decided that, as the technical regulations for the event need to be agreed before the event, Renaults request was inadmissible for this event.   Thus they have to meet the original technical directive on throttle opening and not the 50% they had lobbied for.  This leaves Renault having to run a mapping which is not optimal for reliability and Mercedes can run their mapping.

After much expectation on the effect of the 10% off-throttle limit, what transpired over the opening practice sessions brought more confusion than clarification. As practice got under way it transpires that the expected 10% limit was in fact not applied to all teams, nor was the dispensation to the different engine manufacturers communicated clearly to all the others. This brought much confusion to fans and media alike, as well as bringing a heated debate between Martin Whitmarsh and Christian Horner in the Friday press conference. Its been reported that Renault engines have been dispensation to run at up to 50% throttle when the driver is off the throttle pedal, and slightly less well reported that Mercedes engined teams are able to run a fired overrun.

However, the situation was explained to me by several key technical staff in the Silverstone pit lane. The communication and political issues notwithstanding, the status is at least technically clear.

Firstly I gained detail of what the proposed 10% rule actually consisted of. In order to prevent teams using off-throttle engine maps to continue to drive airflow over the diffuser for aerodynamic benefit, the FIA proposed a pair of changes to what’s allowed when the driver comes off the throttle pedal. Firstly the well known 10% limit on the throttle opening, but secondly a ban on injecting fuel into the engine when off the throttle. The intention of this pair of changes was to ban both hot and cold blown engine maps.

Of course this was the FIA proposal; the original date of the Spanish GP was delayed while the teams lobbied their cases to the FIA, giving their reasons why such changes were unworkable given the timescales and restrictions on development.

Now we need to understand what goes on within the engine when a driver lifts off the throttle and the subsequent effect that has on other aspects of the car. Unlike in road cars the driver in an F1 car doesn’t leisurely lift off the throttle and delay the braking phase. Instead the driver may be at near maximum revs, when he will simultaneously lift off the throttle pedal completely and hit the brake pedal hard for the initial downforce aided braking event. During the braking event the gears will be sequentially selected, further peaking revs as the car slows. This sudden closing of the throttles blocks off the inlet to the combustion chamber, but the cylinder will continue to pump up and down at a great rate. This creates huge stresses inside the combustion chamber and the vacuum created will suck air past the piston rings. This will rapidly slow the engine, creating too much engine braking effect, which in turns creates downstream stresses in the drive train and over-brakes the engine. The excessive engine braking effect will make the car nervous on throttle lift off, regardless of any subsequent aerodynamic effect.

So engine manufacturers find different solutions to ease the stresses and braking effect of the driver lifting off the throttle. In the seasons before EBDs there were several different strategies in place, the driver was able to alter overrun setting to tunes the cars handling, and driver switching between teams found the change in overrun settings needed some adjustment to both their driving style and sometimes with the engines settings. So overrun settings were already an issue before EBDs, and many strategies were already outside the intentions f the 10% rule.

Renault have been open and said their engine already runs open throttles on the overrun, this both eases the blow-by and stress issues, it also usefully cooled the exhaust valve, an alternative to using excess fuel to cool the back of the valve. This year the Renault sport are believed to be running as much as 90% open throttle on the overrun. This is what’s best known as cold-blown mapping. Earlier this season and through out free practice at Silverstone, the three Renault engined teams, had a distinctive loud overrun note, which continues briefly as the drivers picked up the throttle out of slow turns. As the throttles are open more than other teams, the induction noise is far greater.

Mercedes HPE, equally have their solution, this is the so called fired-overrun. When the driver lifts off, fuel continues to be injected into the engine and sparked within the combustion chamber. This offsets the engine braking effect created by the engine, giving a smoother transition from on throttle to the overrun when off it. As a result this means there is less engine braking effect. This gives Mercedes the freedom to define braking bias and KERS charging, without having to account for engine braking. Effectively decoupling the engine braking effect from the actual action of the braking system. As with Renault’s pre-EBD mapping Mercedes solution is analogous to the hot blowing mapping. At Silverstone the Mercedes engined teams had a particularly clean overrun sound. Where as Ferrari had far more cracks and pops as the engine slowed.

With both engine manufacturers having long established overrun strategies that have critical impacts on the basic engine design or the braking system, it will be hard to rapidly switch to a very strict overrun mapping as demanded by the 10% rule. Both manufacturers lobbied the FIA to be allowed to retain elements of these old overrun strategies, while still emasculating their current strategies. The FIA have been able to see the mappings used in 2009 through to the current day, as the code is held by the FIA since the advent of the single ECU (SECU). They’ve been able to see the engines have had these long established mappings, but also how they have become more aggressive since the EBD has been developed.
So the FIA relented and although we will commonly call this the 10% rule, the actual throttle will allowed up to 50% and some fuel can still be injected and burnt in the engine. This sounds like a climb down by the FIA and unfair to different engine manufacturers. But the unreported events at Silverstone this afternoon are fairer than the picture being painted by the teams and the media. Its true that Renault were given their greater throttle opening, but also Mercedes were given their fired-overrun, but these dispensations have been given to every engine manufacturer, so Ferrari could have more throttle opening or Cosworth could develop a fired overrun. As I understand you can one but not both of these options, so no 50%-open with a fired-overrun.
Although the communication and timing of these clarifications appears to be wanting, the final rules clarification meets the basic needs of individual engine suppliers, but still maintains parity between the four parties involved. There is no doubt this allows some secondary benefit of greater flow through the diffuser on the overrun, but this is still greatly reduced over what’s been raced already this year. So there will be reduced aero effect and no further arms race in developing these aggressive strategies. After the furore dies we have been left with w reasonable compromise on reducing engine effect on aerodynamics, before the fuller bans comes into effect with periscope exhausts next year.

FOTA Fans forum: Technical Openness

At the FOTA Fans Forum, which was held the McLaren Technical Centre (MCT) in the UK last Thursday, one of the sections was on the technical side of the sport. It was refreshing to hear these people admit that F1 needs to open up more on the technical side. As the sport and the cars are so fascinating technically and not just mobile billboards for the Marketing departments. Their comments (below) echo what I have found when talking to the teams designers and technical directors, even people at the lower level of the technical want to get more of the technical message out to fans. However at some point the the paranoia of secrecy and the apparent unwillingness of the Teams PR depts, do not always allow journalists access to these people.

These technical directors were posed the question if more Technical information should be released to the fans?

Paul Monaghan, Red Bull
“We’ve got to be prepared to open up, there are probably some commercial difficulties to overcome, but in terms of making more available, I think it would be good to do so”

Paddy Lowe, McLaren
“What’s fantastic about about the fan base of F1 is that its generally a very technical audience. that sets you apart from the football fan lets say. you understand, and you want to understand, technology and we want to keep feeding that”

James Alison, Renault
“There is so much all the teams do that is more or less the same. All of us could talk about the technical detail without betraying any particular secrets of our particular team because we’d just be revealing things that go on in the sport that are interesting, which we’re all doing.”

More on the FOTA Fans Forum via James Allens website

McLaren: European GP wing movement

UPDATE: While I am still awaiting a response from McLaren, I have had a direct reply from Charlie Whiting, FIA Formula One Race Director, to my questions. He responds “The slight anomaly you refer to has been investigated and we have told the team improvements need to be made”. I also asked if this area is subject to any specific deflection tests or construction of the wing\pylon interface “there is no stated permissible deflection of the parts you’re referring to, we do of course have a blanket restriction on any bodywork moving but, in some cases, we define limits given that no bodywork can be designed infinitely rigid”. So it seems any movement there should not be evident at the British GP.

McLaren sported a new front wing at the European GP last. Although the endplates, main plane and cascades were all new, it was the way the wing mounted to the nosecones pylons that has caught attention. From the onboard Tv footage the wing can be seen to apparently and progressively separate from its mounting. However this movement is caused, it is likely to spark questions on flexible aerodynamics, although its clear the McLaren was passed as legal by the FIA scrutineers checks.

http://www.twitvid.com/NLDQ1 Video via Ian Doreto

As McLaren place their camera pods on the front wing pylons (the two vertical plates bonded to the nose cone) and also slightly behind them, the onboard footage presents a clear view of the side of the pylon and the wing below it.

Typically the construction of this area is relatively simple. The wings central section has a metal plate bonded to it, through which run threaded studs. These studs pass up inside corresponding holes in the pylons and are then fastened down with nuts. This makes the assembly rigid, with no freedom of movement. Teams fit a spacer shim into the gap, to ensure the wing sits at the correct static ride height when fitted to the car. Almost every team follows this basic design.

However from the onboard footage, it appears that the McLaren wing is hinging on the pylons allowing the wing to rotate backwards slightly. What can be seen is a gap incrementally opening up at speed towards the rear of the interface between wing and pylon (pictured above). Then as the car slows, the gap closes back up to nothing. I have seen two onboard shots of both the cars in the race and both appear to behave in a similar way (pictured below).

This would have the effect of flattening the front wings angle of attack at speed, decreasing downforce. Depending on the way the diffuser sheds downforce at speed, this would have the effect of inducing understeer, probably for the purpose of making the car more balanced and stable for the driver at high speed. The practice of flattening front wings has been seen before, historically it’s not been unusual to see a front wing flap flatten out at speed, as the compliant flap is subject to aero load.
By achieving a better aero balance at speed, this achieves a different effect to the Red Bull, which appears to droop the front wing into an anhedral shape at speed, this creates more downforce rather than shedding it. So Red Bull are seeking more performance, rather than managing the cars balance.

McLarens wing behaving in this way could be explained in several ways, perhaps as the result of a manufacturing fault, I will ask the team if they had any such problems with the new front wing in Valencia.

I have heard previously from several ex-designers and technical directors, that even in recent seasons teams have had springs in designed into this area. Designed in such a way, that a gap opens up by creating some compliance in the wing\pylon interface. Normally by having a sprung mount, the spring being preloaded to meet any FIA test, but above the FIA load the spring is able to move the wing in a controlled manner. This is of course a far easier way to control the wing than compliance designed into the carbon fibre lay up. The rules do not specifically state that such compliant mechanisms are banned, although a similar wording has been created for the T-Tray splitter mounting. Following the precedent of the Red Bull front wing, which also appears to move at speed, it seems that any movement of the wing is allowed as long as the wing passes the FIA deflection tests. Which is in turn contradicting the FIA demand for bodywork to be rigid and having no degree of freedom in relation to the body/chassis unit.

3.15 Aerodynamic influence :
With the exception of the driver adjustable bodywork described in Article 3.18 (in addition to minimal parts solely associated with its actuation) and the ducts described in Article 11.4, any specific part of the car influencing its aerodynamic performance :
– must comply with the rules relating to bodywork ;
– must be rigidly secured to the entirely sprung part of the car (rigidly secured means not having any degree of freedom) ;
– must remain immobile in relation to the sprung part of the car.

Valencia: Ban on engine map changes

A matter of days before the first practice at the European GP, there was surprising news that there will be a further restriction on engine mapping for this race. Ahead of the more stringent ban coming at the next round in Britain, in Valencia teams we have to start the race with the same engine map as used in qualifying. As with many of these FIA clarifications there is little information and even the teams have been hard pushed to provide full responses to my questions on the matter. With what limited information we have I will try to explain the impact of this change.

Currently teams are free to alter engine mapping settings between qualifying and the race, as these parameters are not part of the Parc Fermé regulations. Thus with the advent of hot & cold blown diffusers teams are able to run a much more aggressive map for their qualifying laps for more downforce and of course faster laptimes. Unable to run these maps through out the race, due to the fuel consumption penalty and the heat generated in the engine\exhausts, after qualifying teams plug in a laptop and revert the engine map to a softer race strategy. These qualifying maps give a considerable laptime gain, some reports suggest over 0.5-0.8s per lap. This is also one of the reasons for Red Bulls superior qualifying pace relative to their race pace, as I reported last year https://scarbsf1.wordpress.com/2010/07/10/red-bull-map-q-the-secret-to-the-teams-q3-pace/.

Clearly Charlie Whiting is still unhappy that the engine is being used for aerodynamic advantage, he has brought in a restriction on the maps being changed after qualifying. I asked the teams what has been introduced. McLaren told me “same engine map from Q1 until the start of the race”. A fact also confirmed by Lotus and Renault. Therefore no specific engine maps are being banned, merely the teams have to make the judgement call, on whether they can run the first stint on an aggressive map or qualify on a softer map.

But this appears to only the basic principle of the rule revision, clearly there’s a lot more to it than that. It leaves the question of what can the driver change and when can he do it, as well how is this to be enforced. Again McLaren were able to explain some more “I think the intention is that you can’t alter the map – it would take too long to change it during a pitstop as you’d need to plug a laptop into the car”. So while we are used to seeing the drivers altering engine settings from the steering wheel, there is a limit to what he is able to achieve. Renault also were able to confirm “Some parameters are adjustable from the steering wheel, but not all. In Valencia, you can officially change your exhaust setting during the first pitstop, but you would need to plug a computer to the car, so it would take ages”. So it’s clear the driver is either not able or not allowed to make the changes from the Qualifying to the end of the first stint.

From what I’ve learnt, there is a difference between what we define as an engine map. There’s the settings the driver commonly makes via the steering wheel to fuel\igniting\rev settings, to either increase power or lower fuel consumption\preserve the engine. But there’s also a level above that, to which the driver has no access to via the steering wheel. The engines parameters are managed via the Standard ECU (SECU), which also includes peripheral items such as the steering wheel interface. Thus to make changes to the main map the team need to plug a laptop into the car and makes changes via the software interface.

Its been suggested the team could code a control on the steering wheel to alter the map between aggressive and soft and simply switch in the first stint, however the FIA have access to the data off the SECU which controls these parameter and could detect if this change had been made, which would be in contravention of the rule.

However its likely that the driver can still make changes to setting on the main map, during the first stint from the steering wheel, but not to the extent where it will go from full aggressive to soft. But simply to find a tactical short term boost or fuel consumption saving, as they normally would during a race.

Equally people have suggested the teams could develop a quicker method for altering the map at the first stop, rather than plugging a laptop in. I guess this is a possibility, assuming the SECU supports any alternative method. But it should be pointed out that the aim of this rule is to stop the aggressive hot blown qualifying maps, which will be restricted to the point of ineffectiveness at the next race (Silverstone), so it’s unlikely any teams would risk any literal interpretation of this rule. If indeed there isn’t already any additional info available to the teams or direction form Charlie Whiting that isn’t public that prohibits this.

If a team were able to run the first stint with an engine and fuel tank that could cope with the load from the aggressive map, the laptime gain might offset the time lost at the first pitstop. This Risk\Reward scenario might be played out in Valencia, but I’d doubt any of the top teams with these aggressive maps would take such a risk without weeks of testing and pitstop practice with the laptop. The short notice of this rule change no doubt aided the FIA in circumventing these sorts of workarounds.

Another workaround suggested has been set a lap fast lap on an aggressive strategy, pit, then change maps and run a lap on the race strategy. But the FIA are already beating this trick in two ways. Firstly the same map must be from used Q1, therefore all qualifying laps will have to be made with the same mapping as for the race start. This will further add to the deterrent of teams using aggressive maps, as this accounts for several extra laps in Q, as well as the first stint. This will be hard on the engines life and the fuel consumption. Secondly just as with tyres, it’s the set up on which the cars fastest lap is set that becomes the set up to start the race. It seems there are few workarounds to the rules.

The impact of this rule is teams will have to reign in their qualifying maps, this will cost them laptime and obviously any teams with an overly aggressive map will suffer more. The introduction at Valencia is significant as blown diffusers give the car more low speed downforce, although Valencia is not the slowest track on the calendar these maps will provide a big chunk of laptime at this circuit. Paddock rumour places Red Bull towards the top of the list of Q-Map users, so we could expect a smaller gap between them and Ferrari\McLaren, but I doubt this would account for all of the laptime difference. McLaren are also a team with a well developed Q-map, where as Ferrari are still believed to be immature in this area of development. Further down the field the other Renault engined teams and the Cosworth teams are likely to suffer less. Which should bring the tailenders a few tenths closer to the P1 time in Q1 reducing the fear exclusion on the 107% rule.

Going forwards this rule change is likely to be retained; further reducing the special qualifying set ups that the FIA have spent the last ten years restricting. It seems now there is very little the teams can do to alter the car between a qualifying and race set up.

Video: ‘The Flying Lap’ ScarbsF1 reviews DRS, Engine mapping ban and the Canadian GP

2012: Exhaust Blown Diffusers are banned

This is an evolving story, I will update the post as more info becomes available

It has been reported in Pitpass.com that exhaust blown diffusers will be effectively banned in 2012. Currently exhaust outlet can be anywhere on the car, many teams aim the exhausts at parts of the diffuser to create greater downforce. Red Bull for example blow theirs under a 5cm opening in the floor, Renault blow theirs at the floors leading edge and Ferrari\McLaren and many other teams blow theirs over the top of the diffuser.

An example of current exhaust location

Along with the hot overrun engine mappings, teams have been exploiting the exhaust gasses for aerodynamic gain. Something the FIA have been increasingly uncomfortable with. According to the BBC “From 2012, pipes will have to extend to between 330-350mm beyond the rear wheel centre line, will have to be in a space between the lower rear wing and top of the diffuser and will need to be circular in dimensions, with a vertical cut-off”. This is effectively at the trailing edge of the rear tyres. Although some careful placement might find a tiny aero gain, the massive benefit of the EBDs will be lost.

Following the Technical Working Group meeting this week, Autosport reports that the ban on blown ovverrun engine maps will go ahead from Silverstone, but a compromise on the location of 2012 exhausts has been reached.  Teams wil now be mandated to use periscope style exhausts as were the norm from 1998 until this year when low placed exhausts became the universal fitment.  It remains to be seen how the rules will enforce exhausts in this location.

For 2012 the exhaust must exit behind the rear tyre and between the diffuser and beam wing (yellow)

With the initial ban on how overrun engine mappings, Renault and red Bull stand to lose out the most. With the full EBD ban in 2012, it is again these teams with the most to lose as each of these teams blow beneath the floor. Teams such as Ferrari and McLaren who have committed to aggressive blowing the diffuser will also stand to lose from the ban.
Engine suppliers will have to work on ways to make the engines work with such long secondary exhaust pipes, teams will have to work out the packaging of the exhaust, blowing most likely near the cars centre line, which brings the exhausts close the hydraulics and gearbox. In this area blowing the underside of the beam wing could be exploited, or  blowing the gurney at the diffusers trailing edge will also be an attractive option.  Blowing outboard is unlikey to be attractive, as it create the longest exhaust routing and exposes a lot of floor to the heat radiating from the exhaust pipe. In both case the longer exhausts will obstruct airflow to the diffuser, forcing some compromises in packaging.
One benefit for fans will be the clear line of sight to the exhausts, allowing us once more to the flames on the overrun and when revving on the grid before the start.