Renaults Hungarian Sidepod Fire

The silver canister is visible towards the front lower of the sidepod - via nextgen-auto.com

Update: Lotus Renault GP, have provided me with this response from Technical Director James Alison.

Three days after the incident on Nick’s car, has the team identified the reason why it caught fire after the pitstop?
J.A.: As with most accidents, several incidents combined to cause the fire that Nick suffered in Hungary. First of all, we ran a slightly different engine mapping strategy in qualifying, which produced hotter than normal exhausts. We believe that this elevated temperature and caused a preliminary crack in the exhaust pipe. We presume that the crack then propagated during the laps to the pitstop – this was not evident to us as we believe that the failure occurred upstream of the place where we have a temperature sensor. We believe that Nick then came in with a partially failed exhaust. This pitstop took longer than normal, the engine was left at high rpm for 6.3 sec, waiting for the tyre change to be completed. Under these conditions, a lot of excess fuel always ends up in the exhausts and their temperature rises at around 100°C/sec. This temperature rise was enough to finish off the partially failed pipe and to start a moderate fire under the bodywork.

There was an explosion shortly after Nick got out of the car, on the left. What was it?
J.A.: This was caused by the air bottle which supplies the air valves in the engine. It has overheated in the fire and failed.

Will you have to modify the car before Spa and if yes, is the August factory shutdown a handicap?
J.A.: The incident was highly undesirable, as it has caused us to write off a chassis. We will take steps prior to the next race to reduce the likelihood of a further fire and to ensure that the air bottle cannot overheat. We are in touch with the FIA both to provide them with a full report of the incident and also to explain to them the actions we are taking to prevent a reoccurrence.

As Nick Heidfeld made a pit stop at the Hungarian GP, there was a problem with one of his wheel nuts. This kept the car stationery for an extra 10-12 seconds. In readiness to leave the pit, Heidfeld kept the engine pegged at maximum revs. This extra delay was enough for the exhaust to start to overheat the surrounding bodywork. Without the usual pit fans blowing air over the bodywork, the carbon fibre soon started to smoke and then caught fire. Heidfeld was then released from the pit, as the wheel nut was properly fastened. Sparks were being blown from the car as he sped down the pitlane, this was the action of the exhaust blowing the fragments of the burning carbon fibre bodywork and not electrical sparks as some have speculated. The airflow over the bodywork only fed the flames and by the time he was at the pit lane exit his sidepod was well alight. As it was the bodywork itself that was on fire, the flames were on the outside of the sidepod and looked perhaps more alarming than was actually the case. Bodywork fires are not uncommon and teams have well rehearsed drills to meet the car in the pitlane with the pit fans and a precautionary fire extinguisher. Although it’s fair to say these sorts of fires are normally prevented by detail work to the shape and heat shielding of components early in the cars testing. Particularly around the exhaust which is the greatest source of heat within the sidepod. This year’s unusually long faired-in exhausts contribute a greater risk and the Forward exhaust exit (FEE) of the Renault only adds to the proximity of the exhaust to bodywork. With more conventional exhaust blown diffusers (EBDs), the exhausts are run along the floor to ahead of the rear tyre; these are slightly easier to manage. Additionally the heat shielded ducting for the Renault FEE, also provide a route for flames to exit out of the front of the sidepod, making the flames in closer proximity to the driver. This isn’t to say the Renault FEE is inherently unsafe. Any F1 cars bodywork left to overheat will see the flames rapidly spread across the skin of the cars sidepod bodywork.

What made Heidfelds fire more concerning was the apparently explosive moment when debris and gasses were blown out from the cars sidepod as the marshals sprayed extinguisher foam over the burning bodywork.

As the R31 came to rest, the driver jumped out and the fire marshals arrived from a post a few meters up the track. Two marshals tackled the blaze, running from behind the car to around the front to direct foam over the sidepods. As the first marshal carried on towards the rear of the car, the second marshal arrived at the front of the sidepods. Then there was this burst of debris and gas from the front of the sidepod. This appeared to slightly injure the marshal who limped around to the rear of the car. Renault have confirmed “he is ok. No injury. We are sending him a nice gift”. Shrapnel from the burst lay several meters away from the car in the pitlane exit lane. As we’ve seen fire’s are relatively rare in F1, oil fires being the more common and spectacular, but it’s very rare for a burning car to have this sort of violent moment.

Sidepods contain a multitude of systems; many items being solely in the left or right hand sidepods, rarely are any internals symmetrical left to right.

Typical components in this area are.

• Water radiator (LHS)

• Oil radiator (RHS)

• Hydraulic reservoir (varies)

• Nitrogen cylinder for the engine Pneumatic valve return system (varies)

• KERS battery water radiator (RHS)

• SECU, PCU, Battery, Lap time beacon (typically RHS)

• KERS PCU (RHS)

It’s important to note, sidepods do not contain the KERS batteries or the MGU. Also the gearbox oil and hydraulic fluid coolers are mounted atop the gearbox. There is very in the of little hydraulic systems being in the front of the sidepods, only the lines for the power steering passes this far forward in the car.

Seeing the explosion was not backed up with a further blaze of burning oil or steam from water radiators, its unlikely these burst in the fire. Then as most of the electronics are in the right hand sidepod, again these can be discounted. This leaves the obvious exception of the nitrogen cylinder. This is required as F1 engines do not use valve springs but instead a pneumatic pressure keeps the valves pressed open against the cam. In order to provide this pressure and as the system loses a little pressure during the race, a pressurised chamber maintains the required pressure. This comes in the form of a ~half litre aluminium cylinder. (Circled red – twitpic.com/5yycsi )

On most F1 cars and indeed Renaults all the way up to last year’s R30, teams mount these small cylinders inside the cockpit to protect them from crash or fire damage. Renaults R30 placed this on the hand side of the car, down on the small amount of floor between the driver’s seat and the side of the monocoque. But this location is not mandated by the regulations. Pictures of the R31 left-hand sidepod without bodywork, show there is an aluminium cylinder placed in the front section of sidepod. This transpires to be the nitrogen cylinder for the engine pneumatic valves. Probably because Renault had to create a slimmer monocoque to claw back the radiator volume lost to the routing of the FEE, they slimmed the monocoque and fond no space next to the driver’s seat to mount the cylinder and placed it outside on the radiator ducting instead. When this aluminium cylinder was heated in the flames and then suddenly cooled by the marshals extinguisher, the casing shattered sending the pressurised gas out in a hail of debris. This failure of a pressurised aluminium structure could also be the water radiator failing, while some rumours point to this the lack of the plume of steam ejecting from the sidepods after the initial blast, suggests to me this is unlikely. But to be clear, this wasn;t a chemical explosion, merely the failure of the casing of a pressurised vessel. as nitrogen is both intert and not liable to high rates of the thermal expansion

Comment by the team to news websites seems to back this theory up http://www.gpupdate.net/en/f1-news/265636/heidfeld-s-fire-caused-by-overheating-exhausts/ . Although I have yet to have direct confirmation from a source within Renault.

Seeing this was the first instance of such an occurrence that I can recall, I would imagine this might be examined by the FIA and technical directive issues asking teams to place this item in a more secure position to protect it and track officials from a similar incident.

More analysis of Renaults Front Exit Exhaust

http://scarbsf1.wordpress.com/category/front-exit-exhaust/

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

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.

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 http://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.

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History: Periscope Exhausts

Following the meeting of the Technical Working Group, the FIA have agreed to mandate periscope style exhausts from 2012. This has been in an effort to rid the sport of exhaust blown diffusers, a trend that has dominated aero development in 2010 & 2011. While initially it was the FIA’s intention to move exhausts to the rear of the diffuser, the teams preferred to route the exhaust out of the top of the sidepods “periscope” style. This solution is far more aero neutral and prevents teams developing new complex exhaust routing to gain what little aero advantage there is from the rear exit. Also it benefits the engine suppliers who don’t have to retune their engines for long secondary exhaust pipe lengths.

It’s interesting to note the history of the periscope exhaust, as this was at first a retrograde step in aerodynamic development. Historically F1 cars ran their exhausts straight out of the back of the car. Only the introduction of ground affects and turbo engines forced a packaging rethink to exhausts routing through the top of the engine cover. When ground effects were banned and teams sought to find some aero gains at the rear, it was Jean Claude Migeot, who was then the head of aero at Renault, doing the exhaust blown diffuser solution in 1983. This trend continued through the late nineties, when F1 engines were normally aspirated and the V10 format became the trend, as were ever higher rev ceilings. Teams were finding the aerodynamics sensitive to throttle position and slowly they started to move the exhaust away from the diffuser kick line and towards the trailing edge to reduce this sensitivity. This necessitated quite long secondary exhaust pipe lengths (the single pipe section leading from the multipipe collector). This passed the exhaust in close proximity to the gearbox and hydraulics as well as the rear suspension, which at the time was starting to be made form carbon fibre. Back in ate nineties materials were not as advanced as they are now and heat resistant materials were not as effective.

In 1998 this forced Ferrari into a rethink of the exhaust solution. Head of Aero at Ferrari at the time was Willem Toet, he explained to ScarbsF1 how the periscope came to be. He starts with an honest explanation “I was sort of forced into the periscope exhausts at Ferrari”. At the time Ferrari were developing their 90-degree V10 engine, seeking to find higher revs to regain the power lost from the more powerful V12s. This engine developed was the catalyst for the move according to Toet “Long pipes didn’t suit the engine at all so we needed to go short”. Unable to create the long secondary pipes the traditional rear exits were unviable, however their first solution was not immediately the periscope, “We found the best solution, quite an aero gain at the time, was to exit the exhausts out of the sides of the bodywork beside and ahead of the rear tyres with an extra panel to protect the tyres from hot exhausts. That’s how the car was launched”. This solution met the initial aero and engine development targets, but was not without its problems, as Toet adds “The materials available at the time weren’t so advanced and we had mechanical grip and driver feel problems associated with the rear suspension, still steel on the Ferrari in those days, deforming under temperature. We were forced to abandon this due to the handling feel of the car”.
Again the workaround was not the periscopes “We went to a simple blown diffuser but the performance loss was “noticeable”. We then tried a short pipe leading into but not connected to a secondary pipe but had some fires due to exhaust flame outs off throttle that then caused problems”. With other solutions finally exhausted Toet shifted to an up and out exhaust solution, which we tend to call periscopes, but he terms snorkels. Toet concludes “And so the exhaust snorkels were born. Then with lots of optimisations we got them to work quite well (not as good a solution aerodynamically speaking as the side exits but not bad in the end). The solution then allowed for tighter rear bodywork which began to bring further benefits”. Looking at the rear of the 1998 Ferrari F300, the first design of periscope stood the test of time and in concept hasn’t changed much in the ten subsequent years. Ferrari of course had initial problems with the periscope design. Although the shorter exhaust bundle kept the radiated heat away from the side of the gearbox, where the suspension and hydraulics are packaged. But instead the hotter exhaust plume played over the rear bodywork of the car and critically over the suspension. Ferrari suffered suspension problems despite their early attempts at heat reflective materials being added to the upper wishbone. Detail development continued and by the end of the season Ferrari had proven the periscope was a workable solution.

F300 periscope exhaust, courtesy of Gurneyflap.com

It was a while before other teams followed the periscope solution. As their engine suppliers demanded shorter pipes, their carbon fibre suspension struggled with the heat and the throttle sensitivity upset the handling. So eventually every team switched to the up and out solution. By 2001 nearly all teams had gone this route. Leaving just Minardi and McLaren with blown diffusers. Minardi exiting their exhaust relatively high up over the trailing edge of the diffuser, at the time technical director Gabrielle Tredozi told me this was to reduce heat rejection and throttle sensitivity. However the team did trial some low exit exhausts, similar to McLarens at the high speed tracks of Indianapolis and Monza. But for 2002 the Asiatech V10 engine Minardi were to use demanded shorter exhausts and Minardi went for the periscope design with the Gabrielle Tredozi designed PS02.
Up to the 2001 MP4-16 Adrian Newey at McLaren directed his exhausts low down through the central boat tail of the diffuser. But in 2002 Newey was forced to go with periscopes, as he explained to me in my first ever interview with him in 2002 “The 2000-2001 cars had the same engine, we now have new engine, and different V angle that’s obviously changed, some of the packaging of the car the engine also has some different requirements, which is affecting us. Requests from the engine supplier Ilmor were different exhaust system requirements which meant we could no longer continue with putting the exhausts exits out through the floor so we had to go for top exits”. I pressed him if this was purely for engine demands, which he confirmed, but when asked if it was specifically for shorter pipe lengths he cautiously replied “I’d rather not go into details; we couldn’t accommodate what was wanted”.
So by 2002 every team had exploited the less sensitive, but aerodynamically inferior periscope design. It seems the effect of blowing the top rear wing or beam wing was of little advantage with the periscope design. However the trend in the 2000′s was for ever tighter sidepods, the periscope design enabled teams to go much further with the slimness of the coke bottle area as the pipes no longer needed to exit rearwards through the tail of the sidepod, they could be packaged further forwards in the sidepods. Slimmer and slimmer rear ends were developed, all to the benefit of the diffuser airflow, which in itself reaped aero gains. Initially the teams had the exhaust collector point upwards, with the short secondary pipe pointing up the turning 90 degrees to exit rearwards horizontally. As sidepod heights and widths reduced it became better to point the collector forwards and curl the secondary pipe in a “U” bend to point backwards. This placed the bulk of the exhaust system above the radiators and left very little volume to the side or behind the engine, to the benefit of the slim rear aerodynamics.
During the 2000s teams continuously varied the exit format of the exhaust. At some points during the decade an oval exit was used with a small horizontal stiffener added for strength. Also the exit varied between flush to the sidepod surface and protruding through the bodywork. Ferrari adopted a protruding exhaust, surrounded by a tall fairing that aided the extraction hot air from the sidepods. Some teams also exploited the hot exhaust for rear tyre temperature. Jordan exited their exhaust high and wide through the flip up ahead of the rear wheel. They had optional exhaust pipes that sent more of the exhaust plume over the rear tyres to increase their temperature. Renault also briefly tried a scoop that caught some of the exhaust plume and directed it over the rear wheel.
Then in 2010, it was Adrian Newey who returned the exhaust position to low down on the RB6, in order to exploit the fast moving exhausts gasses passing over and through the diffuser, the Exhaust Blown Diffuser was reborn. Several teams discarded periscopes during 2010 for low exhausts. But for the start of 2011 every team had gone for a low exit and the periscope disappeared. It appeared as though it was lost from F1. Now with its mandatory renaissance in 2012, it will be interesting to see if teams can further develop this simple concept further.

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.

Red Bull – Monaco floor analysis

Monaco is a unique venue, not just for the layout of the circuit, but also the pit lane facilities provided to the teams. With no space for a conventional paddock and pit building, the teams park their transporters away from the small pit garages. Thus parts have to be ferried in-between the trucks and the pit, as well as parts being stored in the upper floor of the pit facility. Luckily for F1s technical observers, this presents an opportunity to see parts not normally exhibited in front of fans. Just such an opportunity presented itself to Jean Baptiste (@jeanbaptiste76) who saw Mark Webbers floor being lifted up to the mezzanine, through the crowd he was able to a quick photo of the entire assembly. From a single picture we have been to gather a lot of info on the design of Red Bulls floor. We’ve confirmed where the exhaust blows, how the trailing edge forms a flap and exclusively how the starter motor hole is blown by ducts in the upper floor. There also a wealth of detail not normally visible, although not unique to Red bull, seeing this detail is a rare treat.

Firstly we can see that this is a floor that has been run on the car, evident by the burns and dirt generated to what would otherwise be pristine black and silver floor. I suspect this is a floor assembly used for free practice, as the floor ahead of the rear tyres still sports the tyre temperature sensors. These are not typically run from qualifying onwards.

We can also see that the floor is in one complete piece, which is unusual. Normally the front t-tray splitter section is removable. Perhaps with the front splitter being lighter this season, it no longer formed of a large piece of ballast, making having a one piece floor more convenient. Plus the new more stringent splitter deflection tests are probably easier overcome with a single structural assembly, rather than two assemblies bolted to the car. Plus we can see the front bargeboards are a permanent fitment to the floor, whilst the sidepod fins are unbolted from the floor and remain attached to the sidepod fronts.

Exhaust routing

Silver coating (zircotech) and gold film provide heat shielding

We’ve seen many pictures of the Red bull exhaust system, how it curls down to pass the exhaust along the floor towards the outer 5cm of floor aside the rear tyres. Obviously no exhausts are fitted to the floor, but the general heat protection within the engine bay appears a coating applied to the carbon floor (most likely Zircotech). Additional local heat protection is provided with separate heat shields and gold reflective sheet, under the exhaust area. The exhausts then run out of the engine bay and along the floor. Again reflective coating is used on the bare floor beneath.

The exhausts route along the floor and blow beneath the diffuser

We can then see the exhaust exits to the edge of the tyre decks 9the small section of floor between the tyre and diffuser. This area is extensively cut away and the edge of the floor is a metallic part which curls up to encourage the exhaust to pass beneath the floor and into the diffuser. We have seen from pre-season (http://scarbsf1.wordpress.com/2011/02/02/red-bull-rb7-open-fronted-exhaust-blown-diffuser/) that the exhaust curls up into the outer top half of the diffuser, further proven by the additional heat protective coating applied in this area. Recent pictures of the Ferrari being craned away in Spain, show that Ferrari do not shape the floor to encourage as exhaust flow to pass under the floor, McLaren are also more similar to Ferrari than Red bull in this regard. As of Monaco 2011, Red Bull were the only team to passing the exhaust flow under the outer edges of the floor towards the diffuser.

Trailing edge flap

On the diffusers trailing edge a flap aids downforce

Red Bull switched to a revised diffuser at the Chinese GP, this exploited a new treatment to the top trailing edge of the diffuser. Rather than a simple Gurney, the team formed a flap above the trailing edge in-between the rear wing endplates. This was not a new feature in F1, Toro Rosso launched their car with just such a flap and historically many cars have sported the detached gurneys of flaps. The Arrows cars in the 2000s sported just such devices. Completely legal, these simple aerofoil sections of bodywork, sit within the allowable area for bodywork at the rear of the car. Much like the gurney, these devices aim to use the high pressure air moving over the diffuser to create a low pressure region above the diffuser exit, to drive more flow out of the diffuser beneath. Effectively making the diffusers exit area larger than a simple exit.

Blown starter hole

Two inlets lead to ducts (yellow) that feed the Starter Motor Hole with airflow

What’s most interesting from Jean Baptistes picture are the two ducts set into the floor ahead of the diffuser. Looking closer we can see these two inlets, lead to ducts that pass inside the engine bay and either side of the starter motor tube. The starter motor hole in the boat-tail of the diffuser is a wide slot, so I believe these ducts blow the starter motor slot. Until other teams cottoned on to Newey’s exploitation of the outer 5cm of floor, most teams pointed their exhausts towards the Starter Motor Hole (SMH), as a way of using the high velocity exhaust gas, to drive more flow through the diffuser and thus create lower pressure for more downforce. With Newey’s outer blown diffuser he could not exploit the large SMH with his exhausts, so this solution allows him to exhaust-blow the diffuser and passively-blow the SMH. By passive-blowing, I mean the exhaust is not used to blow the SMH, but simply the normal airflow over the car. Of course the effect of this passive blowing is dependant on the airflow approaching the ducts inlets. The RB7 has all enclosing bodywork around the gearbox and floor. So airflow could not directly lead to the SMH. So Newey has had to duct flow to this area. It’s unlikely that the flow arriving at these ducts is that powerful, having had to pass around the sidepods and over the fairings covering the exhausts. This is likely to be a small aero gain, albeit one that other teams with similar gearbox fairings could employ. Should the engine mapping ban make the outer blown diffuser solution too sensitive to throttle position, then this duct could receive the exhaust flow to still provide a degree of blown diffuser.

Other details

The T-Tray is formed with the floor and has an opening normally covering by the plank

Away from the unique Red Bull features, the floor exhibits a lot of standard practice for contemporary F1 floors. In Red Bulls case the floor completely encloses the underneath of the car, only a small open section in the t-tray splitter is open. This opening will be enclosed when the plank is fitted to the car. There’s probably a matching section of ballast attached under the chassis that fits in the hole, allowing the ballast to sit a precious few millimetres closer the ground.

An older Red Bull floor (this floor can be purchased via F1-247.com)

With other teams more sections of the floor above the plank are open, and in some cases the base of the monocoque also forms the floor, so the removable floor section has even larger openings.

Enclosed Lower Leading: note the ECU inside the hollow section

The area forming the front lower leading edge of the floor also has to house the Side Impact Tubes (SITs). Clearly with a one piece floor like this, the floor cannot be removed with the SITs still attached to the monocoque. Many teams have the SITs removed with the floor, by unbolting them at the side of the monocoque. This would appear to be the case the RB7 floor. Although not visible in this photo, presumably the removed SITs remain with the car, so possibly this floor is being changed, rather than stored temporarily for refitting.

Such is the tight packaging of the area within the sidepods; space for electronic boxes is limited. We can see a small black box and loom within the enclosed section of floor. Just to the rear of this there appears to be a blue-grey square set into the floor. This is probably a transparent window for sensors to project through, most likely the ride height sensors. Normally three are fitted, one to the left one the right and another at the front or rear, these three ride heights can be extrapolated to provide the engineer with the cars attitude to the track.

Note the wiring for sensors passing around the floor

There is also a reasonable amount of wiring loomed around different areas of the floor. When wiring was seen dangling from Vettels front wing mounts earlier this year, people were quick to assume, this related to wing flex. But instead a lot of the car is instrumented, both for data acquisition but also troubleshooting during the race. In the case of the floor, two measurements are commonly taken, pressure and temperature. Pressure sensors log the pressure beneath the floor, should a car suffer damage in the race, the team can tell from the telemetry if a change in pressure readings are likely to cause handling problems. Equally teams have been known to fit temperature sensors the titanium fasteners holding the plank to the chassis. If these skid blocks, ground too frequently they will heat up. This delta in temperature will alert the team that the plank might be suffering undue wear and cause legality problems in scrutineering.

More pictures from @Jeanbaptiste76

http://twitpic.com/57snf2

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FIA: Ban on Aggressive off-throttle Engine maps

 

Teams have been adopting exhaust blown diffusers (EBD) since last year and in 2011 every team has exploited the exhaust to some extent to help drive airflow through the diffuser. As I have explained in previous posts on the subject (http://scarbsf1.wordpress.com/category/exhaust-driven-diffuser/), the problem with EBDs is that they create downforce dependant on throttle position, so as the driver lifts off the throttle pedal going into a turn, the exhaust flow slows down and reduced the downforce effect, just at the point the driver needs it for cornering.

If a team want to really exploit the benefits of an EBD then they need to resolve this off-throttle problem. Last year Red Bull exploited a different mapping of the engine when off throttle (see http://scarbsf1.wordpress.com/2010/07/10/red-bull-map-q-the-secret-to-the-teams-q3-pace/ ). By retarding the ignition when the driver lifts off, the fuel is no longer burnt inside a closed combustion chamber, but instead the fuel and air burn in the exhaust pipe, the expandign gasses blow out of the exhaust exit as though the engine is running . This creates a more constant flow of exhaust gasses between on and off throttle. The problem here is that the mapping uses more fuel and creates excessive heat in the exhaust pipe and at the exhaust valve. Renault reported that both Red Bull and Renault used 10% more fuel in Melbourne compared to last year, most likely due to these off-throttle mappings.

With these off throttle mappings the fuel burns in the exhaust pipe, not the cylinder

 

As the engine suppliers have become increasingly comfortable with the heating effect of these off throttle mappings, teams have been able to use more of this effect in the race. One of Red Bulls advantages this year according to McLaren is their use of aggressive engine maps for downforce. At the Turkish GP several people pointed out the engine note on the overrun on Alonso’s Ferrari during FP2. Teams have clearly started to drive the engine quite hard when off throttle, to keep the diffuser fed with a constant exhaust flow.

Now the FIA have stepped in to limit this effect. Although initially scheduled to be in effect from this weekends Spanish GP the change will now take effect after Canada. This clarification is based on Charlie Whitings changing opinion of how these mappings are used. At first some mapping was allowed, but these increasingly aggressive and fuel hungry mappings are changing the engines primary purpose. Effectively when off throttle the engine is being used purely to drive the aerodynamics, this contradicts the regulation on movable aerodynamic devices. Although this is a vague interpretation it can be justified.

What is now required is that the engines throttles (at the inlet manifold) must be closed to 10% of their maximum opening when the driver lifts off the throttle pedal. Unlike in most road cars, in an F1 car the engines throttles are not under the direct control of the driver via the pedal. The throttle pedal is instead the drivers method to request power\torque, the cars SECU then controls the level of throttle required to meet the drivers request. So as the driver lifts off the throttle pedal, he is no longer requesting power\torque and therefore the throttles should close. what happens with these EBD mappings is that the throttles remain open, Fuel continues to flow then the delayed spark from the plugs sends the burning charge down the exhaust pipe.

Now with the throttle closed to 10%, the amount of fuel that can be burnt will be limited and thus the blown effect will be reduced. so drivers see will a bigger variation in downforce as they modulate the throttle pedal, making the car less predictable to drive.

Blowing the exhaust under the 5cm of outer floor (yellow) will be most penalised by the ban

 

All teams will be affected to some extent, however the more aggressive that teams have been with the exhaust position relative to the floor, then the greater they will be affected. From the start of the season Red Bull, Ferrari and McLaren have blown the exhaust at the outer 5cm of diffuser. this area is allowed to to be open and bow the exhaust gas under the diffuser for greater downforce. these designs will be most greatly affected by the clarification. Renaults Front Exit exhaust is also likely to be a victim of the change. Many teams have been developing Red Bull Style outer-5cm EBDs, such as: Williams, Lotus, Virgin, Sauber, While Mercedes are rumoured to be adopting a front exit exhaust. These may to need be shelved after Canada, in order to employ a less aggressive EBD.

Renault – Front Exit Exhaust Details

Copyright Sutton Images via Formula1.com

Although we almost didn’t believe it when the rumours emerged at the launch of the Renault R31, The car does indeed have exhausts that exit at the front of the sidepods. We (@f1fanatic.co.uk and I) managed to see, understand and get the first pictures of the unique set up (http://scarbsf1.wordpress.com/2011/02/01/renault-r31-front-exit-exhausts-fee-explained/). Now the car can be seen stripped in the pit garage, we can see exactly how the Renault packages the exhaust.

The exhaust system routes the four pipes into a collector which then continues to point forwards and direct the secondary pipe low underneath the radiator to the front of the sidepods. As the exhaust routes gasses at up to 1000-degrees C, it needs insulating to protect the other equipment housed in the sidepods. Renault appear to have fitted an insulated jacket around the main length of pipe in the sidepods. What is clear from the set up is that Renault had to raise the radiators to allow the pipe to ass underneath. The R31 has unusually large sidepod inlets and this might to cope with the ducting of the cooling airflow to the laid down radiator.

Copyright: Andrew Robertson (@JarZ)

From these pictures via Andrew Robertson (@Jarz) we can see the front detail around the sidepods. Although the exhaust outlets are not seen here, the problem of the final routing is apparent. Teams need to fit beams to the side of the monocoque for side impact protection. Known as Side Impact Tubes (SITs) there are two pairs to share the load, with one upper pair and a lower pair. As these SITs are heavy, the majority of the work is down by the lower pair, to keep the weight low in the car. Correspondingly the lower SITs are larger and the exhaust needs to pass over these and down to exit sideways.

Copyright: Andrew Robertson (@JarZ)

Renault has packaged these lower SITs into a narrow front and wider rear Tube. The exhaust will angle down along the front tube to blow still pointing downwards across the lower leading edge of the floor. We can see the metallic heat protection on the SITs.

Copyright: Andrew Robertson (@JarZ)

More info on Front Exit Exhausts and how they work – http://scarbsf1.wordpress.com/2011/03/22/trends-2011-exhausts-and-diffusers/

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