The NASCAR Next Generation (Aka Gen 7) vehicle took the track in earnest in late 2021, beginning the final team tests prior to its debut at the Busch Light Clash at the Coliseum, an exhibition race that starts the 2022 season. Its development has spanned several years, thousands of hours of design and testing work, numerous suppliers and, of course, one global pandemic. The following is a small part of the story of its development from an aerodynamic standpoint, as told by managing director of aerodynamics for NASCAR, Dr Eric Jacuzzi. NASCAR’s last generation vehicle, the Generation 6, or Gen 6, as it’s known, was introduced in 2013. With its forward emphasis on manufacturer identity, it was a breakthrough for the sport. It was the first time in many years that the entirety of the vehicle, from nose to tail, was unique to each manufacturer (within certain parameters), harking back to the fiercely competitive manufacturer racing days of old. After eight years of racing, though, it was time to update the look of NASCAR’s top series to more closely resemble their roadgoing counterparts, which too had evolved over that stretch.

Couping the roof

Perhaps the greatest departure of the Next Gen (Gen 7) vehicle from the Gen 6 is the move to a coupe-like roof line, and the symmetry of the rear of the vehicle. The Gen 6 was designed around a sedan greenhouse profile, which at the time was more relevant to the manufacturers’ vehicle mix. However, the introduction of evocative coupes such as the Ford Mustang and Chevrolet Camaro meant fitting the production body style onto that sedan greenhouse proved challenging. The side profile of the Next Gen vehicle is therefore a blend of the lines of the Camaro, Mustang, and TRD Camry, featuring a lower roof line and swooping back glass design that works well for all three cars. With the greenhouse decided, the next step was to move to another stylistic sore point: the tail.

The Gen 6 was optimised to race on left-turning, high-banked ovals, generating stability in yaw via a large rear overhang and a 2.5in offset to the right. This offset generates rear side force, resulting in a restorative, positive yawing moment to the car. It also allows the car to ‘correct’ itself when the driver oversteps the bounds of traction at the rear. However, achieving all that presented significant aesthetic challenges for manufacturers and NASCAR, since car designs not only had to be stretched at the rear, but also have different shapes on the left and right sides. This leads to various interpretations of what is acceptable, and often lengthy lists of revisions from NASCAR in terms of qualitative styling, as compared to the production vehicle.

Spitting image

Introducing a symmetric body eliminated the majority of these issues and presented a car that is a near spitting image of its street counterpart. Another factor in moving toward a symmetric body was the evolution of the NASCAR racing calendar. The introduction of more road courses and short tracks reduces the need for the car’s design to focus on high-speed ovals, and more toward a shape that can do it all: ovals, road courses and short tracks. Speaking of the tail, another key feature of NASCAR vehicles is the spoiler. It’s a blunt instrument, but a historical element that completes the stock racecar look. It is also a very effective device from a sanctioning body perspective for controlling top speeds, which is critical for fan and driver safety due to the proximity of both to the walls and fencing at most oval tracks. Another element that influenced vehicle styling was the decision to duct cooling air out of the car once it passed through the radiator. This concept is not new to vehicles in general but, for all previous NASCAR designs, the radiator simply emptied into the under-bonnet (hood) region like a production car. The counter incentive this created was less radiator cooling flow, which resulted in more front downforce and less drag. This added up to extremely hot engine temperatures.

NASCAR previously investigated ducting radiator air out of the engine bay area of the cars at the 2019 All Star Race at Charlotte, and it was decided to implement this feature on the Next Gen in an effort to promote longer engine life spans and reduce car temperatures. Two zones were opened up for OEMs to place their radiator exits, with the majority of the underlying radiator ducting common. Either louvred or open designs were permitted, based on the styling desires of the OEM, which is apparent when comparing the different design paths of the three vehicles. Cowl induction at the base of the windscreen has been a mainstay of NASCAR competition for decades but is not compatible with heated radiator air exiting out of the bonnet. It was therefore decided to take the engine air from the front side of the radiator core rather than create an additional opening in the front fascia for stylistic reasons. With these elements settled, the OEM aero teams and design studios went to work on what would become their 2022 challengers.

Carbon underbody

One of the largest departures of the Next Gen car, aerodynamically speaking, is the lack of side skirts. While skirts are effective at generating downforce in a simple manner, they give the appearance of the cars being sealed to the track, along with the inevitable – and undesirable – wrinkling and deformation they experience. The Next Gen car is the first NASCAR vehicle to feature a full carbon fibre, aerodynamically-driven underbody. That said, the Generation 6 cars had become substantially developed to take advantage of the high-speed undercar flows. The difference is one is purposefully built, the other had to ‘pretend’ to be for other reasons.

Development of the underwing was done in parallel with common elements development on the body. The process was primarily undertaken in CFD, with over 2000 runs dedicated to underwing development for both performance and lift-off safety testing. Since the original introduction of the Next Gen was slated for 2021, it was decided that the only viable path to making the timeline was to go from CFD straight to full-scale testing. Scale model options were evaluated as well, but with confidence in the simulation work and world class local wind tunnel facilities, it was decided to move ahead and target only four development tests of 20 hours each to finalise the underwing. NASCAR has always placed a premium on safety for both drivers and fans in all instances, so it was important to establish early in the process that no design decisions would adversely affect the lift-off speed of the car. It was also decided to use a 14-point CFD ride height map, which included front and rear ride height, yaw and pitch sweeps to characterise as fully as possible the performance of the vehicle and any impact changes had. This map was later used in wind tunnel testing at Windshear wind tunnel in Concord, North Carolina.

Aero goals

Early in the process, the goal was to match the relative aero performance of the Gen 6 vehicle, primarily in terms of total downforce and balance. Because the Gen 6 car had a restorative yawing moment due to the rear asymmetry, teams were able to run very high front downforce percentages, often exceeding 50 per cent. It was understood early in the process that the reduction of rear side force due to body symmetry would impact the useable aero balance, but initially it was a guessing game, although not entirely without value. Early aero development focused on matching the evenly distributed downforce number. The thing about aero development in general is, it’s much easier to make front downforce compared to rear downforce. Minor improvements in shapes, fit and finish yield greater results at the front of the car, where the highest energy air is found. As that air loses energy toward the rear of the car, it becomes much more difficult. Add in the fact that the ability of the rear of a car to generate downforce is hampered by the mass in front means, basically, that the front of any car has the first choice on making downforce.

After reviewing ride height data from early tests and determining where the drivers felt comfortable after the car was adjusted, it was easy to identify that it correlated with a downforce distribution of approximately 30 per cent front. This meant moving the downforce balance rearward by 12-14 per cent, a significant departure from the existing Gen 6 architecture. This is where the front downforce-generating exercise paid dividends – by knowing what could reverse the front downforce gains. At the front of the car, one of the most substantial downforce-generating characteristics, aside from ground effect, is the outwash of the front splitter in front of the tyres. The outward sweep of the splitter footplate, which is a wear limiting device for track contact, proved to be a very significant generator of downforce. Reducing the balance required reversing this original development. One of the advantages of this was that it funneled some of the previously ejected high energy air toward the rear of the car.

Diffuser evolution

At the rear, the diffuser also underwent an evolution at the same time as the front splitter when the balance change was implemented. The original diffuser was relatively simple in its design so wind tunnel testing could begin and provide an early opportunity for validation against CFD. With confidence in the CFD predictions and a need for more rear downforce, a multi-week CFD study began to refine the diffuser. It was decided to keep its kick line (the most forward edge) as far toward the centre of the car as possible. It was evident as well that the outer tunnels were ingesting the front tyre wakes. In an effort to draw in higher energy air from the outside of the floor, the rear of the rocker boxes is ramped upward, and the diffuser outer tunnels feature a double hump design. This pushed the initial outer tunnel ramp forward and outward. To accommodate the maximum suspension droop, these outer tunnels then move back downwards before resuming an upward trajectory. Rear downforce performance is largely constant over a range of ride heights, and floor pressures are very consistent across a range of ride heights.

On the lift-off safety front, NASCAR evaluated the vehicle in CFD before testing at the Automotive Center for Excellence (ACE) in Oshawa, Canada and the Chrysler Technical Center’s Aero Acoustic wind tunnel in Auburn Hills, Michigan. The Next Gen features the passively deployed bonnet (hood), and roof flaps NASCAR uses in all its vehicles, but the diffuser presented a new opportunity to add another safety device – a diffuser flap. This is held in place at the centre of the diffuser and, when deployed, releases downward and blocks the central tunnel of the diffuser. This creates a low-pressure region behind the flap and increases the lift-off speed of the car when nearly backward by 10-20 per cent. The flap was originally designed to operate via a pressure base deployment system, but it was found to be much more effective to deploy the diffuser flap via mechanical release connected to the right-side roof flap by a flexible cable. Overall, the path of development for the underwing was aggressive but successful, thanks to the strong correlation between CFD and the wind tunnel.

OEM submission

After nearly nine months of private development testing, all three OEMs submitted their vehicles at the end of August 2021 for three grueling days at Aerodyn wind tunnel in Mooresville, North Carolina. The advent of a new vehicle allowed NASCAR and the OEM aero teams to further refine an already tight Gen 6 submission process. Aside from qualitative and quantitative CAD reviews, the wind tunnel performance of the body is the most critical component. To ensure the most accurate and repeatable testing environment possible, NASCAR uses a dedicated submission vehicle capable of having different OEM body panels mounted to it. Because of the enormous time demands of three manufacturers’ wind tunnel testing in the same period, three clones of the submission vehicle were produced for the OEMs to use in their private testing efforts.

The submission process itself consists of two distinct components. The test opens with NASCAR setting the performance targets using its generic body, with several repeated runs at the start of the test. The OEM vehicle(s) must pass the first gate with no radiator flow, which must be worse in lift and drag than the generic body. With the radiator flow open, the OEM body must have a radiator velocity ratio (VR) within +/ 0.005 of the NASCAR generic body, which also occupies the centre of a lift / drag box with tolerances in each direction. The body must fall within this box, or the test is considered a failure.

OEMs are allowed up to five different design attempts per shift though, practically speaking, it is difficult to get through more than three configurations. The submitted OEM bodies are scanned in the wind tunnel and compared to the submitted CAD for each design, with strict tolerances enforced to ensure each test article is representative of the design intent. Testament to all three of the manufacturer aero teams is they all passed their submission tests on the first attempt. With the bodies submitted and approved, work began on converting the bodies into composite components. The body uses flanges and a common mounting system to attach to the chassis, with adjustment built in of up to 0.15in in each direction to accommodate manufacturing tolerances. Body inspection at the track will still be conducted by NASCAR’s Optical Scanning Station, which compares a rapid photo scan of the car to the approved CAD surface of the vehicle. This scan is located off targets on the chassis and has a tolerance of +/- 0.15in for the body, which presents challenges to the teams to build to that tolerance but also keeps the competition on a level playing field.

Thermal updates

As production parts began to arrive in early 2021, the first major test of team cars occurred at Daytona International Speedway. Over two sweltering hot and humid days it became readily apparent the production cars were much hotter than either of the test cars NASCAR had previously utilised. Some of this was attributable to inadequate insulation and material changes in production, but a great deal was due to the ingestion of hot radiator air into the cockpit and inadequate evacuation of air from the cockpit. These issues had not arisen during single-vehicle testing, due to some seemingly minor design differences between the prototype vehicles and production. One example was the use of Kevlar composites to form the seals between the exhaust and the cockpit, which appear to have resulted in greater conduction into the steel chassis of the car since no heat is dissipated from the composite surfaces. Another was at the rear of the car, where the production wheel tubs further closed off the rear of the boot (trunk) area, sealing in hot air from the transaxle cooler.

After Daytona, the NASCAR R&D aerodynamics team embarked on a month-long extensive study of the problem, thermally modeling the entire vehicle in much more detail than it had previously. This resulted in a laundry list of changes that were implemented at the Charlotte Roval test in mid-September, which included windscreen driver cooling ducts, slotted rear glass, a full right-side window, the elimination of left side NACA ducts into the cockpit, a NACA duct on the floor of the car and opening up the rear to evacuate the transaxle heat. These changes yielded substantial gains in the instrumented cars at the test.

The post Developing NASCAR’s Gen 7 Aerodynamics appeared first on Racecar Engineering.

Barely 48 hours after the official launch of the new Haas car, it was announced that his NASCAR team, Stewart-Haas would make a shock switch from Chevy to Ford in 2017. Rumours had been flying around for weeks that it would be Ganassi who would change name plate but nobody had linked SHR to the blue oval.

“I think it was just a business decision, it brings stability and give us a vision for the future” Haas explains of the switch. “Ford has a long term vision of what they want to do in racing and parallels what we want to do. GM has been great to us over the years and we were not really looking to change but the synergies that Ford brought to the table we just could not pass that up.” With Fords global motorsport programme going through a significant change at present it must be wondered what those synergies are, could Haas for example move into the WEC with the new GTE Ford programme or even bring Ford back into Formula 1? Haas smiles and refuses to be drawn only stating that “I think running at Le Mans would be great, the Indy 500, Le Mans, Daytona and Monaco too. Those are all big races, I like the idea of doing that.”

Ford had been linked to a Formula 1 return in 2014 with the stillborn Cosworth power unit, and there have been suggestions that in future Haas F1 could morph into a Ford works outfit. Haas will not rule out working with the right partners in future (as he did with Tony Stewart in NASCAR) but stresses that Haas F1 is in Formula 1 for the long term.

While it is very early days for his new team in F1 Gene Haas has been spending a fair amount of time in the Formula 1 paddock learning about the new world his organisation has joined. “It is all kinda similar, its not totally foreign but everything is a little different, open wheel car racing is fundamentally different to stock car racing. But the speeds of the F1 cars are incredible” he explains.

It might be expected that one of the biggest differences between NASCAR and Grand Prix racing is the budget required to compete credibly but surprisingly Haas is not overly concerned with the cost at all. “The cost of running a four car team in Sprint Cup and a two car team in Formula 1 is about the same. Ferrari has a budget of $400m but some of the smaller teams do it on $60-$70m a year. Its the same in Cup, the average cost there is about $15m per car plus the driver, but there used to be the start and park teams who did it for $5m” he reveals.

Indeed at a time when many in the paddock are complaining about the cost of power units and even suggesting dumbed down ‘budget engines’ Haas takes a perhaps surprising stance; “when you consider the performance and complexity of these cars and the money you have to pay for the engines and what goes into them, its not a bad deal.” Haas is no stranger to buying his power from a external supplier, for years in NASCAR he has sourced his V8’s from Hendrick Motorsports but in 2017 SHR will use Roush Yates Fords.

With the design and build of the VF-16 well underway in 2015 Haas had find someone to drive it (or indeed two someones), and there were immediately rumours of big names from NASCAR jumping ship with Danica Patrick topping the rumour mill with the soon to retire Jeff Gordon and occasional Indycar runner Kurt Busch also mentioned frequently. But the reality is none of them would qualify for the superlicence required to race in F1 and Haas had to look elsewhere. One of its drivers Gutierrez, a works Ferrari driver was not a huge shock considering the close links between Haas and the Italian company, the other driver, Grosjean was also logical, the underrated Swiss (who races under a French flag) was without doubt the best available.

“The drivers at the top in F1 are extremely expensive, but by and large the salaries are comparable between NASCAR and F1” Haas reveals. “That said the Cup drivers have to work twice as hard and the races are longer and Romain knows that!”

Having a team that races in both NASCAR and Formula 1 will lead to inevitable suggestions of drivers switching series in a guest capacity, not least from the drivers themselves. Haas admits that this is almost a certainty. “Tony Stewart wants to come to all these races he loves this stuff. Kurt Busch is very keen to drive a Formula 1 car and I know Romain is interested in the stock car so it would be interesting to work out a swap. The talent these guys have mean that they could do it, I think Kurt Busch could drive the Formula 1 well, and Romain in NASCAR. I think it might be easier for Kurt though, the thing about stockcars is that they are not very good cars, they are hard to drive, the are very heavy, the power level is the same but there is not much downforce. You need a mentality to be able to drive in those packs, the F1 guys are used to driving round by themselves and trying not to hit someone. In Cup you are almost mandated to hit someone (Haas points out that is a joke, “it is not mandatory just extremely likely!”).”

But it is that difference between the cars that Haas describes as the biggest difference, and in some ways the hardest thing to get used to. “Formula 1 is on a much higher level in terms of technology as NASCAR limits the technology. We have just got fuel injection in Cup, we have steering boxes from cars out of the 1940’s things like that. NASCAR is trying to keep the cars simple but the problem with that is some of that stuff like those steering boxes do not even exist anymore in production cars.” It seems that he is one of a growing number in NASCAR who would like to see the next generation of Sprint Cup car feature more modern technology (see Stockcar Engineering magazine for more of that).

The different styles of politics and governance between NASCAR and Formula 1 is also a stark contrast for Haas. It is clear that Haas is somewhat unimpressed by some elements of Formula 1’s current set up, highlighting the organisation of a F1 commission meeting in Geneva during the second day of pre-season testing in Barcelona. “I don’t think having someone fly to Geneva during the first test just for a 1.5 hour meeting is good. They don’t seem to utilise the teams time efficiency to say the least” he complains. When you realise that the time it would have taken to travel to the meeting was longer than the duration of the meeting itself you can see his point, especially as most of the attendees also had to travel from Barcelona.

In the USA the France family have controlled NASCAR since the very first meeting and foundation of that organisation during a meeting in North Wilkesboro, NC (not as often claimed at a certain hotel in Daytona Beach). While in Formula 1 the sport has been controlled in the modern era largely by Bernie Ecclestone jointly with the FIA. “I think Bernie is a benevolent dictator, the France family is more like an aristocracy” Haas explains, his position is unique as he deals with both on a regular basis. “Bernie is the man that everyone goes to if they need something, my point of view is that Formula 1 would be worse off without him. The way Bernie works is to have a little bit of democracy. Where the Frances autocratically tell you how it is going to be, Bernie will ask your opinion and then sometimes you get to vote on it, in NASCAR until very recently you didn’t get to vote on it. NASCAR is changing a little bit at the moment though with a bit more of that democracy coming in. But in NASCAR the structure is clear, in F1 you have Bernie and you have got the FIA and I don’t know how that all works yet, (a mischievous voice from the sidelines interjects – “nor do they” – the culprit will remain nameless) but that is what it is.”

The new approach of the Haas team, in terms of car development, team structure and general attitude is likely to have a more profound impact on Formula 1 than many realise. Its low cost approach of maximising the rules in terms of build it or buy it has lowered the bar in terms of entry requirements for other new teams and is known to have caught the eye of a number of other prospective entrants as well as a few of the current teams.

The post Gene Haas, NASCAR vs F1 appeared first on Racecar Engineering.

When the NASCAR Sprint Cup teams take to the track at Daytona for the start of the 500 this weekend they may look the same but there a lot of tiny rule changes that could really spice things up.

Almost every part of the 2015 cup car has been changed in some way. So ahead of the ‘Great American Race’ we take a chance to look over those changes.

A new electronic rulebook features 60 changes, and some of them like the changes to tyre pressures, side skirts and lug nuts could result in a fairly wild end to the ‘500.

The new engine rules will come into force at Atlanta, the second race on the schedule.

Meanwhile most of the cars that will take the start at Daytona will look pretty similar to those that started the race last year apart from a few new paint jobs here and there, apart from the Toyota’s which have all new bodywork on them. After the Japanese brand performed really badly in 2014 winning only two races NASCAR allowed TRD to rework its Camry, partly to make it look a bit more like the production car, but really to make it more competitive.

It now features a new nose, hood, side windows and tail. These have all been performance balanced using a common wind tunnel test programme with Ford and Chevy, but Toyota thinks that it has found ways to improve on track performance that do not show up in the wind tunnel. This seems to be the case after Matt Kenseth won the Sprint Unlimited as Daytona last weekend. Many of these small changes likely relate to underbody ducting which the teams can tune and develop themselves.

A FULL ANALYSIS OF BOTH THE NEW TOYOTA SPRINT CUP CAR AND THE 2015 NASCAR RULE CHANGES CAN BE FOUND IN STOCKCAR ENGINEERING – GET YOUR COPY FOR FREE BELOW

Stockcar Engineering is a highly targeted technical publication read by those responsible for engineering and running stock cars at all levels. While other publications focus on cars that compete in Cup or circle track racing, such as Modifieds and Late Models, Stock Car Engineering is concerned with the application of advanced technology throughout oval racing. From British Short tracks to Sprint Cup races at Daytona, Stocker Engineering covers it all, just so long as it is cutting edge technology.

You will not find set up tips or step by step how to guides, instead you will find the latest advance engineering solutions and their applications in racing, often before they are even common knowledge in the Cup garage!

In the new issue we take a look at how the new rules change Sprint Cup, Toyota’s new look Camry (and just how Kenseth was able to drive how he did), we take a look at what NASCAR R&D is really up to and we find out about ECR Engine’s secret weapon.

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The post NASCAR 2015: Sprint Cup rule changes explained appeared first on Racecar Engineering.

The rolling hills of Pennsylvania in the Northern United States hold a mysterious secret buried deep under Laurel Ridge. This highly classified test site is re-writing the textbooks on aerodynamic development.

The construction of the site took place in 2003 and rumours of existence first surfaced a year later.

Rumours of an abandoned highway tunnel being used by a racing team were the talk of the industry, but details were sketchy at best. Eventually Racecar Engineering managed to get hold of images of the tunnel in use which showed some intriguing modifications, including a large metal structure that has been added to the eastern end of the tunnel.

Tales recounted by hikers reveal a little more about what exactly is going on at Laurel Hill: ‘I had been hearing screaming burn outs and deep-tone V8s blasting through four gears clear from the top of the hill,’ claimed hiker Corey Shaulis, who took some of the pictures seen here. Discarded drums of Sunoco Supreme (a racing fuel developed for engines which operate between 7,000 and 10,000rpm and the official fuel of NASCAR) have also been photographed at the eastern end of the tunnel, and a new surface is clearly evident in some pictures, leading into and under the new structure. It all became clear somebody had built exactly what Paul Van Valkenburgh predicted in the March 1995 issue of RCE – a coastdown tunnel – a tool that combines the best elements of real world, straight-line testing and conventional wind tunnels.
Imagine being able to do limitless straight-line testing in perfect conditions – no wind, controlled temperatures and with a real, full-scale car. In the past this was impossible, but not any more.

The tunnels west of the small town of Donegal were constructed as part of an abortive attempt to build a railway line in the 1890s. After the project failed, the tunnels lay dormant until they were included in plans to build what became known as ‘America’s first superhighway’ – the Pennsylvania Turnpike – a motorway-style road running east to west across the northern state. The new road opened in 1940 with much fanfare and instantly proved a success, but by the 1960s it was clear that the tunnels along the route were bottlenecks and possibly even dangerous to motorists. So the tunnels were abandoned once again, though the one at Laurel Hill continued to be used sporadically for storage and also as a firing range. Then Chip Ganassi Racing lead by Ben Bowlby, came along and changed everything.

Originally, Chip Ganassi himself had found a tunnel near Pittsburgh, but this was not long enough. Then, in September 2003, he discovered the Laurel Hill tunnel half full of road-making material. ‘It was a complete mess,’ recalls Bowlby. ‘Chip asked me what I thought. I said it was perfect. We cleaned it up and then ran a NASCAR down it. We checked the influence of the tunnel on the airflow of the car running at 150mph just to see that we weren’t completely mad. By January 2004, we had ground the old concrete roadway flat, laid a new, quality limestone aggregate roadway, put ends on the tunnel, lit it and started running. At that stage it was very crude. It was simply a sealed, one-mile long tunnel.’

One of the first development projects to be conducted at Laurel Hill was on the 2004 G-Force Indycar “Dallara had come up with an airbox solution that we felt wasn’t going to be allowed so we hadn’t investigated it” explains Bowlby. “When we had gone to the first IRL open test of 2004, we were something like six miles an hour off the pace. The redeveloped airbox meant that the car was fully competitive.”

Using the tunnel allowed Bowlby’s team the ability to turn new designs around quickly. “If we had gone the CFD route or via a scale-model wind tunnel, I don’t think we would have got it sorted out in time (there was a one-month window before spec freeze).”

It works in the opposite way to a conventional wind tunnel where air is forced around a static car, instead at Laurel Hill a real full size car is driven through the tunnel at a set speed and forces are measured. A source close to Ganassi explained more ‘It is straightforward I think. The big thing about the tunnel is the ability to control the environment, making for more repeatable results. It can be heated/cooled to the desired temperature and, obviously, there are no worries about cross winds.’ Climate control means the tunnel is effectively sealed.

Turntables are fitted at each end of the tunnel to allow the car to quickly rotate and drive back in the reverse direction to speed up testing.

Being in a tunnel raises some other interesting problems, best illustrated by using the example of an underground train. As the train moves through the tunnel it pushes air ahead of it, acting rather like a pump. Apparently this is not a problem at Laurel Hill though, as due to its heritage as a railway tunnel it has a large cross sectional area and a racecar a relatively small frontal area. Still some calculations have to be done to take the effect of the tunnel walls and ceiling into account.
Compared to a full-scale wind tunnel, such as the under construction Wind Shear full-scale tunnel at Concord Airport in North Carolina, a converted tunnel may have a number of advantages, not least in power consumption. Whilst a full-scale rolling road wind tunnel requires an enormous amount of electricity to operate, a converted tunnel can be run with a few generators, like Laurel Hill. Rolling road belts and fans need frequent maintenance, whereas a highway tunnel is somewhat less problematic. But the biggest advantage of all is that the converted tunnel allows you to have the car running under its own power, so the ducting and running temperatures would be realistic, while aerodynamically it’s a case of a real car moving through air and over a real road, rather than the air moving over the car and a simulated road.

A basic run in Laurel hill

The car is rolled into the tunnel from the workshop area through the main door, which is then sealed behind it. A systems check is performed on the logging electronics and then the engine is started. When the green light is given the driver accelerates up to the desired speed and then maintains it as the test section in entered, then starts to coast.

As the car passes the first beacon, the logger picks it up, just as a lap beacon would on any racetrack in the world. Then, in a similar fashion to a car finishing a lap, the second beacon is at the end of the test section. The driver then slows the car to a stop or to walking pace and drives onto the turntable at the end of the tunnel, where the car is turned through 180 degrees and the process can begin again. The test car may also tow a second car through the test section to simulate drafting. Similarly, multi-car tests have been conducted with two cars running nose to tail or side by side.

Maintaining a constant temperature, without the need for heating and/or cooling units that could skew data by introducing additional air currents into the test area is harder to achieve. At each end of the Laurel Hill tunnel are ‘environmental control units’, which are AQS Air Quest 1000 dehumidifiers. A Vantage Pro portable weather station provided by the Davis Instrument Corp controls these, along with some additional climate and air pressure systems.

Even though the tunnel may not be perfectly sealed at each end, the centre section should always provide perfect conditions, to the point that testing is still possible even when one end is completely open. However, for extra atmospheric control Ganassi employs a double door at each end, rather like a simple airlock, so the car or personnel can enter the complex without exposing the interior to the ever-changing external environment. When the car is running the roller doors at each end of the tunnel are opened half way and the opening is covered with a clear film, allowing an out of control test car to exit the tunnel into the emergency run offs if necessary.

Laurel Hill’s current configuration includes a 460m acceleration zone, giving a potential test speed of 100mph, but it can easily be reconfigured to allow for test speeds of 120–130mph.  Of course, with cars running at speeds of up to 130mph, you need space for them to slow down again and, as the deceleration zone doubles up as the acceleration zone for the return run at Ganassi’s tunnel, it is also around 460m long.

Given that Laurel Hill is 1384m in length, this allows for a working test section of approximately 420m, as at each end there are storage and turntable areas taking up some of the extra length.  To make the best use of the tunnel, the test section can be moved either way along the tunnel or its length adjusted by relocating the sensors. This gives Ganassi the ability to test both at a range of different speeds and different distances of test.

When the car reaches the test section on a run it passes a data logging beacon and another when it leaves it. The data acquisition system used on the car is largely conventional, and the documentation makes it clear that it is based on the proven Sigma system from Pi Research, though both CGR and Pi declined to comment on the tunnel. Logging is carried out at both 500Hz and 1000Hz.

Inside the tunnel there are a number of visual aids to the test driver, including red and green ‘traffic lights’, distance markers on the tunnel walls and an internal lighting system. However, if this fails the test cars are fitted with auxiliary lights.

It remains to be seen whether any other organisation will attempt construction of a similar facility and, whilst Ganassi does hold two detailed patents on the Laurel Hill track, it could be argued that as the technique was fully discussed 11 years earlier in Racecar, the patent would not be enforceable. Certainly this is the view of the technology’s original inventor, Paul Van Valkenburgh, who said in response to reading the patent: ‘Strange. A waste of lawyer’s time and money. How can they possibly enforce the patent, because of my prior public disclosure? And yet they have revealed details of their operation to the world…’

Ganassi still uses the tunnel as its main aerodynamic development tool,  it is has been enlarged since the 2004 IRL tests. A much larger more advanced version of the tunnel is to be built in England at Catesby, Northampton (below)

The post The secrets of Laurel Hill revealed appeared first on Racecar Engineering.

Covering the cutting edge technology of stock car racing, it is a highly targeted and hardcore technical publication read by those responsible for engineering and running stock cars at all levels.

Whilst other publications focus on Cup or circle track racing such as Modifieds and Late Models. Stockcar Engineering is only concerned with the application of advanced technology throughout oval racing.

From British Short tracks to Sprint Cup races at Talladega Stockcar Engineering covers it all, just as long as it is high tech!

You will not find set up tips or step by step how to guides, instead you will find the latest advance engineering solutions and their applications in racing. Often before they are even common knowledge in the Cup garage!

In the new issue we take a look at how the new rules change Sprint Cup, Mike Coughlan reveals how new rules in Formula 1 will change stock car racing. Some unfair advantages can be found in our products section and the failure of CFD to dominate NASCAR is explored.

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The organisation continues today in the hands of the next generation.

It was not so much their victories, however, as the way in which the Wood brothers revolutionised the business of the pit stop that they are best remembered. It was something that, as Delano recalls, they were not aware of at the time. Others must have been, though, for Delano later learned that rival teams had been making movies of their pit stops. On one occasion, driver Bobby Alison even asked if Delano slept with his jack (before he retired from NASCAR pit duties in 1983, Delano set a record of 77 superspeedway victories as a jack man, a record that has never been beaten). Leonard, too, was unaware that they were setting standards for the future. ‘I was just concerned with what was stopping me from being faster,’ he recounts. ‘Where were our weak points?’

For Delano, it was brother Leonard who was the key. ‘He was real good at coming up with ideas that would speed things up,’ he says. ‘I wasn’t a mechanic, he was – one of the greatest ever.’ It is now generally reckoned that it was Leonard who pioneered the incredibly rapid pit stops that are such a feature of modern racing.

Perhaps unsurprisingly, Delano recalls how it was that Leonard’s ideas speeded up his own task: ‘When we started, that big old jack was sitting there by itself, so it was decided that I should concentrate on that. It was hard work. I carried it above my belt so that when I was running my knees would not hit the jack and make me lose my balance. Leonard also made me a jack, which eventually went into a museum.’

Says Leonard, ‘I designed the plunger and the cylinder so it would take about two to three pumps to get it up. You made the plunger according to the cylinder. It was like a gear in a car. You can gear them one-to-one or have a ratio like 12-to-one. You also took into consideration how tall and heavy the person using the jack was and how much force he could put on the handle.

‘The jacks were heavy and you could strain your back going from one side of the car to the other, so I made one out of aluminum.’ He also removed the wheels and replaced them with a skid plate, thus ensuring the jack would not turn over and making it even lighter.
In the early 1950s, the teams were using four-lug wrenches to remove the wheel nuts. In about 1960, however, Leonard recalls starting to look at what could be done to speed up the process, initially going to power wrenches. (Delano believes the team may have been the first to use an air gun.) ‘Then we starting asking how we could get the socket on the lug faster.

We streamlined the front part of the socket so it went onto the lug immediately. Then when you were taking the lug nut off, it would stay in the socket unless you shook it out, so we put a spring in there to enable you to go from one lug nut to another as fast as possible.  We also machined the threads on the stud so that the lug would slide on and start without cross threading.’

‘So we had the jack up and the tyre changed,’ continues Leonard. ‘What now was the slowest part of the stop? It was the fuel going in.’

At Indianapolis, Chapman and Lotus designer, Len Terry, had streamlined the Lotus 38’s fuel system with an internal venturi for its locally manufactured tank and an improved outlet valve. Many hours were spent filing and fitting the connections of the system so that hook-ups would be fast and there would be nothing to impede a rapid fuel flow. ‘Everything was done to maximise the flow,’ says Lazenby. That year was the first that a gravity-feed flow was used, pressure refuelling having been outlawed late in 1964. A USAC inspector challenged the Woods to a $1,000 bet that they could not pour 20 gallons a minute into the tank. They did not take him up on the wager, not wanting to show their hand prior to the race, but proved the point to themselves by putting in 58 gallons in 15 seconds.

The brothers also spent time sanding and filing the wheels and hubs, and practicing tyre changes with the Lotus, although ultimately that proved unnecessary as Clark ran the full 500 miles on one set of Firestones.

Page 2 – Getting the job done

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Ford took a different approach with the development of the 2013 Fusion racer. Ford Design Center staff, led by Garen Nicoghosian, and Ford aerodynamicist Bernie Marcus, spent the past year doing the early design development, freeing up the Ford race teams to concentrate on weekly NASCAR competition.
“This is a seminal moment in the sport where we had a chance to get it right once again and make sure the race cars are race versions of street cars. And I am proud because I believe we have accomplished just that,” continued Allison.

“I’d like to believe that the Nationwide Mustang was the first step in bringing brand identifiers into design elements, yet retaining great racing,” stated Jamie Allison, director, Ford Racing. “I would suggest we didn’t go far enough in designing the Nationwide Mustang.  Now, when you see the 2013 Fusion, it is identifiable as a Fusion. It was designed, deliberated by, and literally sculpted by the same team that works on production vehicles in the design studio at Ford.”

The Mustang made its NASCAR debut with four races in the 2010 NASCAR Nationwide season before coming full time to the series in 2011. Success on the track was great for Ford and Mustang, but it was the visual cues the Mustang stock car brought in terms of brand identity that laid the foundation for the 2013 Sprint Cup project.

“There is no doubt that was a nice lead-in to what we are doing now with Fusion,” said Andy Slankard, Ford Racing NASCAR Operations Manager.  “We are taking that and probably raising the game two or three-fold by adding sides and a lot of differentiation in the back and more detail up front for the Fusion. Mustang helped us see the benefit of creating detail and making the cars look good.”

In fact, there are fewer common areas that are shared among all four manufacturers with the new 2013 Cup car compared its Nationwide counterpart.
“On the Nationwide car, from the middle of the bumper upwards to the base of the windshield is the area we were allowed to put in brand identity.  The rest of the car is common, which is basically from the windshield base rearward, including the sides and tail, and then the lower nose,” said Bernie Marcus, Ford Racing’s aerodynamicist who has worked on every NASCAR vehicle since the 2004 Taurus redesign.  “We were able to basically put on the upper nose with the grille, headlights and then a hood.”

NASCAR did allow teams to become more creative with their decal package, so Ford Racing developed an intricate 3D decal that actually made the sides appear as though the distinctive Mustang character lines were actually imbedded in the sheet metal.

“When it comes to the 2013 Fusion, we were able to put character lines in the sides, the upper nose and even the lower nose,” continued Marcus.  “We had a lot more surface area to work with on this car compared to the Mustang, so we were able to actually put the character lines in the sheet metal as opposed to using a decal.  I think 80 percent of the design cues in the current cars out there is in the nose, and we’ve been able to carry the more of the production Fusion styling cues into the total race car.

“We went away from true stock car racing and got to a point where the cars we’re racing in Sprint Cup were very vanilla,” added Marcus.  “Moving forward, we have a lot more brand identity; we have a lot more character lines in everybody’s car, so I think you’ll be able to differentiate them a lot more.  I think it will appease the race fans and it will give the sport an upturn because now the term ‘stock car’ racing actually means something again.”

Some of the challenges the design team faced centered around various NASCAR rules and common areas that all of the manufacturer vehicles will share, but there were other more obvious ones that had to be overcome.

“There is a size difference between the production and the race car, and the proportions are so different. The street Fusion is a front-wheel drive, front engine car, and race car is a front engine, rear-wheel drive car with a really long hood, and a much lower and wider stance,” said Nicoghosian.  “The fundamentally different profiles and proportions of the two vehicles, as well as other constraints, presented a bigger challenge than simply taking a Fusion and putting NASCAR stickers on it.

“The challenge was to design a race car with the look and feel of the production car,” Nicoghosian said. “To do this, you have to rely on design identity. We paid close attention to the way we shaped the details on the racer, such as the headlight, grille, and foglight openings, as well as the bodyside sections, character lines, and overall surface language. When parked side by side, the racer and the street car ‘feel’ the same, even though the two share no common surfaces.”
“We’ve really embraced the Design Center’s philosophy and process of how they would design a car for the street,” said Pat DiMarco, Ford Racing NASCAR program manager.  “We started with some conceptual drawings that our design team did, and worked with the aerodynamicists to see what was feasible and what was not.”

That resulted in some 40-percent sized clay models that helped assess the overall look of the car and how it would react aerodynamically in the wind tunnel.  Eventually, a full-size clay model was constructed and reviewed in the design center, much like production models are assessed.  Top Ford executives, including Chief Executive Officer Alan Mulally, President of the Americas Mark Fields, and Board of Directors member Edsel B. Ford II all viewed the car.

Design Features of the 2013  Sprint Cup Car bodies
• Designers addressed the overall proportion of the race car to reflect proportions found in the production Fusion.
• Brand and design cues in the side of the vehicle.
• An identifiable front end grill with the distinctive look of the make.

The new NASCAR Sprint Cup entries will be tested throughout the 2012 campaign in preparation for their racing debut at the 2013 Daytona 500 in February.

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While February Daytona Speedweeks marks the “official” beginning of the 2011 NASCAR season, preparation for the new season began in August of 2010 for The Goodyear Tire & Rubber Company, the exclusive tire supplier of NASCAR’s three major national series. The first repaved surface at Daytona since 1978 posed a unique challenge to Goodyear as the surface would not be complete prior to the October deadline to begin tire production for the race. Using its years of experience, numerous analytical tests and some innovative thinking, Goodyear produced a tire package that performed well and was positively reviewed by drivers during the December 2010 tire test and January NASCAR open test at Daytona.

“This year’s preparation for Daytona was quite a challenge from our perspective, as the repave timing didn’t allow us to conduct a conventional tire test. We had to come up with an alternate plan to get tires in time for Speedweeks 2011,” said Greg Stucker, director of race tire sales, Goodyear. “Since Daytona was being repaved by the same company that did Talladega back in 2006 and given the similarities between the two tracks, we did a lot of testing in Alabama. We then analyzed the results to a test strip that was poured in Daytona and compared a significant amount of historical data we had on the two surfaces.”

After comparing test results from both surfaces and running analyses, Goodyear made its recommendation for the 500. The tire choice was not only validated by Goodyear during its extensive lab performance testing, but once again during the December and January tests, where some of NASCAR’s top talent also spoke positively about the setup Goodyear was planning to bring to Daytona.

“The tires right off the bat felt really good – the surface is incredible and Goodyear did a nice job matching the tire to it…and that’s what it is all about,” said Jeff Burton, driver, #31 Richard Childress Racing Chevy, who participated on the Goodyear-sponsored test. “It’s easy to pave a racetrack – the hard part is having everything mesh together and I feel like Goodyear nailed it with this tire.”

“We knew we had done our homework. We are very happy to have delivered a package and setup satisfied the drivers,” added Stucker. “We were able to use our experience and skill to come up with an innovative solution to this unique challenge.”

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Track Length

The Daytona 500 is the ultimate season opener in professional sports.  NASCAR’s biggest and most prestigious race remains far and away the top-rated and most-watched event in American motorsports, as well as one of the premier sporting events in the world. Daytona recently repaved its 2.5-mile surface. The first NASCAR Sprint Cup Series race run on the new pavement – the non-points Budweiser Shootout – was run last Saturday. That event, combined with a series-wide test in January and a Goodyear Tire Test in December, have led drivers to hint that this could be the wildest Daytona 500 in history. Speeds have already hit 206mph in two car drafts and this is likely to lead to a restrictor plate change for the 500.
There’s a pretty good history in terms of Daytona 500s on fresh asphalt. The inaugural Daytona 500 in 1959, won by Lee Petty, was so close it took three days to declare a winner. In 1979, the first Daytona 500 after the first repave, will forever be known for “The Fight” involving Cale Yarborough and Bobby and Donnie Allison.

For the 2011 ‘500’ there are some significant changes that could change the very nature of the racing. As mentioned speeds have increased but many more changes will come into play on pit road.

• Tyres – Cup teams now are allowed five sets of tires for practice and qualifying instead of six. They must return four of those sets to Goodyear in order to receive their race allotment, and may keep one set of practice/qualifying tires. Tire allotments for race weekends will vary according to historical performance data.

• Dry break refuelling – Introduced in the Truck Series, this goes into effect for all three national series in 2011. It combines a more efficient fueling system with the elimination of the catch-can man, considered the most “vulnerable” pit-crew member. Teams now will use six, rather than seven, over-the-wall pit-crew members.
  
• CoT updates – NASCAR continues to work with the manufacturers and teams to enhance the look of the Cup Series car. The cars have new fronts this season and the body makeover will continue to help appeal to fans and aid manufacturer identity.
  
  The new for 2011 spec COT nose (above) still features the front  splitter but compared to the 2010 spec version (below) it has lost the unsightly stays. Teams had been dedicating significant aerodynamic resources on developing the ‘old fashioned’ layout.
  

So it is clear that the biggest changes in Sprint Cup racing this season won’t be in the driver’s seat, they will be on pit road. Saturday’s Bud Shootout will be the first showing of how teams adapt to the new fuel system and six-man crew, and fans can be on the lookout for a variety of pit-road strategies in action.

New strategy for stops

“You are definitely going to see a different strategy for pit stops,” said Ray Evernham, the former crew chief many credit with making pit stops as important as on-track racing. “You will see different guys in different positions on each stop depending on where in the race cycle you are.” Larry McReynolds, former crew chief and Fox analyst (TV pundit -not a man who analyses foxes that would be silly) , suggested teams will have a detailed playbook for their stops. “For the first few races, teams will be searching for the best option,” he said. “Taking tires will be important every time. Who makes what adjustments will depend on who has a free hand. It will put more pressure on the crew chief in making the calls.”
“Teams will need to learn to calculate the fuel mileage of the new fuel, so there is the potential to run out,” warned Jeff Hammond, former crew chief and Fox analyst. “This will definitely change the strategy for when teams stop and the late-race option for tires-only stops. You’re going to see the new strategy have a big impact on the races early in the season.”

New choreography for six-man crew (it’s not ballet)

The six-man pit stop will be the most visible change on pit road. The catch-can man was eliminated under the new rules, which means the person who used to handle most of the car adjustments is no longer there. But it does improve safety for the team. “The catch-can man was like the meat in the sandwich between two cars,” McReynolds said. “He was the most vulnerable out there. Now they’ve taken away the guy who makes a majority of the adjustments. Without having him to make adjustments, you’ll see a lot of teams trying different approaches to pitting the car. But five years from now, we’ll be saying ‘Wow, can you believe we used to have a catch-can man?’ ”
The change will put more pressure on crew members to perform several positions during the race, which has had crew members cross-training during the offseason. The new pit-road rule will heighten the need for super athletes who can play more than one role,” said Hammond, founder of 5 Off 5 On pit-crew training school. “You’re going to see more cross positions out there. The change will redefine the pit-stop numbers initially. It will definitely slow us down on the race off of pit road. But you’ll be able look at pit road and tell who has done their homework in the offseason.

New fuel impacts stop time, engine durability
The new fueling system puts a premium on accuracy for the gas man, and is expected to lengthen the time it takes to fuel the car. Ethanol also is tough on engine components, and can eat away certain types of polymers and be very corrosive on cast iron and some aluminum alloys. This will put additional pressure on the engine builders and tuners “There have only been a few changes in the fuel system since the 1970s, so this is a big deal for safety,” McReynolds said. “But you’ve got to be accurate when you’re fueling the car.” McReynolds said the nature of E15 will change how teams handle fuel, too.
“E15 is more moisture attractive, so teams will need to be careful how they handle it to prevent contamination,” he added. “They won’t be turning in the fuel at the end of the race to avoid possibly contaminating the fuel reserves. You’ll also see fuel delivered to tracks in tanker trucks instead of being held in in-ground tanks. You’ll also see teams using different strategies on when they fuel and how much they take,” Evernham said. “The speed of the fueling will be critical in the overall pit-stop speed. There also is some concern about the higher flammability of E15 and the expanded number of crew members who come in contact with fuel,” Lunniss said. “More teams are requesting fire-retardant gloves for other positions beyond the gas man, and there is some thought about fire-retardant suits and fueling aprons if we start to see fires on pit road.”

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The latest venue on the European Late Model Series calendar has been announced. The newly built 1km oval at Venray in the Netherlands, is set to host Late Model races in 2011. Several Late Model drivers have visited the venue and setting laps around the 20 second mark with an average laps speed of 95 mph.

The track is 90% complete and will be finished in May 2011. The European Late Models will race at the inaugural meeting, which is to be held on the last weekend of June 2011. This will be a two day meeting and that will be followed by at least two more double headers, provisionally scheduled for last weekends of July and August.
The track features progressive banking in the turns with a top groove of 23 degrees Shallowing out to 11 degrees for the straights. A quarter mile oval has also been built on the infield, allowing the regular short circuit formulas to race on the same bill, completing the weekends entertainment.

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