Posts Tagged ‘Cars’

Steve McQueen: Motoring is a good part of life

Wednesday, August 5th, 2009

Looking though Seloc just now I followed a link to a great article by Steve McQueen from a 1966 edition of Sports Illustrated.  He talks about his love of racing and reviews eight of the best cars of the day.  It’s a good read if you’re a car fan (or a Steve McQueen fan!), I’m not sure whether he wrote more, but if not he should have! :)

Sports Illustrated 1966 Coversi66page1si66page2si66page3si66page4si66page5si66page6si66page7si66page8si66page9

The article is hosted on mcqueenonline.com, and was provided to them by Wade Chitwood.

A weekend with a Rolls-Royce Phantom

Wednesday, August 5th, 2009

Rolls-Royce Phantom - by Julia Martin

I’ve never really thought of myself as a Rolls Royce kinda guy.  My fantasy garage has always been filled with machines from Sant’Agata, Gaydon or Hethel rather than Goodwood.  Sport rather than comfort has always been what’s impressed me.  After this weekend however I might be squeezing one of Goodwoods finest into my lottery win spending plan.

Last weekend I was a very very lucky guy.  How it came about is a long story, but my girlfriend and I found ourselves with a fabulous ‘09 spec Rolls Royce Phantom for the weekend.  A few hundred miles later and I’m smitten. 

The first thing that struck me about the Phantom is it’s scale, it’s simply massive.  I’ve seen them up close before, but it’s always a surprise.  It carries it’s size well though, projecting a huge amount of presence wherever it goes.  On the road it seems somehow smaller.  It’s odd you’re always aware of it’s size, but it seems natural.  That’s not to say that narrow roads and when parking don’t focus the mind though! 

With the only requirement on us a request to put at least 400 miles on the clock, on Sunday we headed out on a road trip to my parents house in London, stopping off to to see friends and family on the way.  It’s a journey that takes us across some great Sussex A and B roads, a 40 minute burst of motorway then a few miles of busy town roads.  The ease with which the Phantom covered those miles was shocking.  The ride is so smooth and the cabin so comfortable that time just flies by.  It seemed like every time I glanced at the (rather good) sat-nav we’d devoured another 10-15 miles off the route.  If you needed to get from one side of Europe to the other I can’t think of a better way to do it.

Climbing into the cabin you soon notice the attention to detail that’s gone into the Phantoms design and construction, it’s a wonderful place to be.  Our car was trimmed in white leather with black lacquered wood and black carpets which, lush as they were, also had thick rugs for good measure.  Every surface inside is perfectly finished.  The stitching in the leather is millimetre perfect no matter how long the seam and the chrome and wood are like mirrors.

The real fun starts at night, with dials and buttons being sharply lit, and subtle lighting around the cabin adding an almost art deco feel.  It’s hard to describe, and photo’s don’t really do it justice.  In the back, the headliner has hundreds of fibre optic strands sewn into it, giving the roof it’s own ‘star light’.

Whilst I didn’t drive – the car was entrusted to my girlfriend only unfortunately – the driving position is high and comfortable.  The view is dominated by the long bonnet and Spirit of Ecstasy mascot.  You tower above other cars, with even big Mercedes and BMW’s seeming small (and dare I say insignificant!). 

In front of you the dash has a large centre speedometer, with fuel and fluid gauges on the right and the and a ‘Power Reserve’ dial on the left.  No rev counter for the Phantom then, just a guide letting you know just how effortless your progress is.  And with a 6.75 litre V12 providing the go, any sensible progress really is effortless.  Despite it’s size the Phantom is a very quick car.  Not sporting, but quick none the less.  By contrast even at motorway speeds there’s next to no noise.  Whilst there’s the underlying sound of a car running, it doesn’t really change with speed.  70mph isn’t noticeably louder that 30mph.  A single seats air conditioning is easily louder than the wind noise even at speed.

What more can I say?  I’ve been very fortunate over the years to have driven and been in some pretty special cars.  Not much has impressed me as much as the Phantom.  Maybe it’s because I’d usually be more interested in performance than luxury, but the Phantom left quite an impression. 

Having the Phantom for the weekend was probably a once in a lifetime opportunity.  Hopefully I’ve done it justice here!  Needless to say, the Monday morning commute in my daily drive Peugeot was particularly long and uncomfortable the following day.  I’d really like the Phantom back.

Lotus Elise vs. Rolls-Royce PhantomRolls-Royce Phantom Rolls-Royce Phantom Power Reserve LightingRolls-Royce Phantom Starlight Headliner

Buying a car should be easier

Sunday, July 19th, 2009

Over the past couple of months I’ve been shopping for a new car.  I’m doing a lot of miles these days as work is 50 miles or so from home, and my old Peugeot just isn’t great doing a hundred miles a day.  Unfortunately my own indecision has seen me bounce between different cars on almost a daily basis!  I just can’t decide.

Whilst I’m sure my girlfriend is probably very bored of me announcing different cars I intend to buy, talking to the various dealerships and seeing how they work has been quite interesting. It’s actually surprised me how there seems to be a curious separation between car companies web presences and their dealerships on the ground.

These days pretty much any information you could want to find out about a car is on the web somewhere.  If you want to read reviews there are sites like Drivers Republic, Evo, 4Car or Autocar that offer one off reviews and long term reports.  Lots of marques have owner run forums where you can read about day to day life with the car you’re interested in.  And of course the company’s own websites have all the spec’s and configuration tools to pick out what options you’d want and the retail costs.  I say retail costs because you can use places like Drive the Deal or Broker4cars to work out what a good price might be and how much discount you should be able to get elsewhere.

With all this info available on the internet by the time you actually speak to someone at your local dealership, the chances are you probably know what you’re after and just want to see it in the flesh and take a test drive.  It seems to me that at the moment car dealerships aren’t setup to deal with customers in this situation.

Often I’ve found that they’re closed after work and run a skeleton crew of sales people at weekends, just the sort of times people are able to drop in.  Last Sunday I tagged along with a friend who is looking to get a new car.  We went to four dealerships, one was closed, and the other three had a single salesman trying to deal with more people than they could cope with.

Most manufacturer websites will let you configure yourself a car –model, colour, options etc – and then save it for future reference.  Despite having this information about exactly what the customer wants, so far I’ve none of the dealers I’ve spoken to have had the ability to recall that saved spec into their own systems.  Each time I’ve had to run though the whole process again, using a different system, with some poor sales guy – wasting both our time.  In fact to be honest the sales guys add very little value to the process, other than being someone to negotiate with.  Having an IT background its a business process crying out for some integration.

From my perspective as a customer, it would seem like the car companies should try to reinvent the way they sell their cars.  I don’t think it would even take that much effort.  Just by shifting opening hours and making better use of the IT systems they already have they could massively improve the customer experience.

What’s in Petrol

Sunday, July 12th, 2009

Last week I was reading my way through the Seloc Lotus forum that I read quite a lot and stumbled on this post by Guy from Opie Oils, one of the advertisers there (fine purveyors of all things oily!). 

It’s a little off topic here I suppose, but I thought it was interesting so asked if he minded if I reposted it here.  He’sa wealth of information and has posted quite a bit of interesting stuff on various car forums in the past.  Anyways, here it is:

What’s in Petrol

Well…………! In The Beginning there was Carbon and Hydrogen.

These got together in accordance with rules forged in the Big Bang (yes, really!) to make methane, one carbon atom with 4 hydrogens stuck on.

A bit later, (only 4000 million years) other atoms started getting together and finally came up with Life, a self-reproducing chemical mix. The reproducing bit was quite fun, but after 600 million years even that gets boring.

So, a more or less intelligent life-form invented The Car and the Motorcycle, the ultimate boredom cure. This was, and is, powered by the Internal Combustion Engine, which must have fuel.

Methane is a fuel, which means it burns in air to produce energy, but unfortunately it’s a gas; a tank-full would propel a Honda 50 for about half a mile.

But! Methane had not been idle since the formation of planet Earth, and had joined up with more carbons and hydrogens to make chains called ‘hydrocarbons’. Well, they weren’t called that at the time. They had to wait for a life-form to evolve that liked giving things names, and a hundred and 20-odd years ago chemists had to learn Latin, so they called the one with five carbons ‘pentane’, the 6-carbon one ‘hexane’, then ‘heptane’ then ….wait for it…. the 8-carbon one ‘octane’ and so on. (If we were naming them now the last one would be called ‘eightane’ so you would need 95 minimum REN for your engine.)

All these things were liquids, very thin and volatile, and pure concentrated energy. The Hildebrand and Wolfmuller (rough 1894 equivalent of the Honda 50) now did 100 miles to the tank full.

Unlike water, these liquids don’t stand around in lakes. They are hidden underground in porous rock so you have to drill for them. The old name was ‘petroleum’ meaning ‘rock oil’ but this was soon shortened to ‘petrol’. The petrol came out of the wells mixed with heavy oil, so it had to be distilled off in an oil refinery.

Early on, the pale coloured stuff that evaporated easily and caught fire very easily was sold as internal combustion engine fuel. It was a simple as that. ‘Octane Number’ hadn’t been invented, but in modern terms this ‘light petroleum fraction’ was about 50 Octane. Now we all know that in the GCSE Science engine The Piston squeezes the air/fuel mixture, then The Spark Plug ignites it to produce The Power Stroke.

The trouble is, with 50 octane fuel if The Piston squeezes too much the heat generated by compression makes the stuff Go Bang prematurely before The Spark Plug gets a look in, giving a Power Stroke with as much push as a fairy’s fart. This is why early engines couldn’t use compression ratios above 4 : 1, and 10BHP per litre was seen as hot stuff.

Engines improved but petrol didn’t and even some time after WW 1 a touring 1000cc engine only turned out about 25BHP, and a hot-shot Sport version with the latest overhead valves would need a good tuner to get 50BHP.

So finally some effort was made to stop primitive petrol going bang too soon, and a variable compression engine was invented for research. (The ‘CFR’ engine, as used for finding Research and Motor Octane Numbers, RON and MON, to this very day.) Early on researchers found that the bung in the CFR head could be really screwed down if a heavy liquid called ‘TEL’ (tetra ethyl lead) was added. This was really effective and cheap, and allowed the ‘straight’ petrol to be upped to 90 or even 100 octane, and a whole load of exciting high-power engines were designed around these fuels.

This leaded fuel survived into the late 1990s, but much earlier an amazing discovery had been made. The shape of the petrol molecules was very important. ‘Octane’ if the ‘straight eight’ version with 8 carbons in a row had an ‘octane number’ of 25. It was only the mutant octane with 5 carbons down the middle and the others sticking out from the sides that gave the best results at high compression. (This special octane is still used as a standard for 100 octane. Proper name is 2,2,4-trimethyl pentane.)

Today, ‘petrol’ is really a synthetic fluid built up from oil industry feedstocks. Very little of it is unmodified distillate from crude oil. It is tailor made to include the best compression-resisting molecules so that no poisonous and polluting lead compounds are needed to reach 95 or even 98 octane. Nothing much is added, apart from a touch of detergent to keep the engine top end clean. Quite a lot of petrol now has 5% ‘renewable’ alcohol as a planet-saving gesture, but this also improves the octane number (by about 1 ) so there’s nothing wrong with that.

Anyway, if you have a motoring holiday instead of flying ComaJet, you are keeping that carbon footprint down….and paying too much tax as well…..but that’s another story.

Playing with Porsches at Silverstone

Wednesday, June 24th, 2009

Porsche 911 GT3 Gen2 

Yesterday I spent a fantastic day at the Porsche experience centre having a sneak peak at the new 911 GT3 with the guys from Drivers Republic

Unfortunately 911’s are a little beyond by price range, so I got to go through a competition on the DR website a couple of weeks ago.  The event itself was part of a two day preview that Porsche was giving for existing GT3 customers.  DR arranged with Porsche to extend the day out to a group of DR readers and offered places on their site.

It was a great day, as well as getting a really good look over the new car we got to chat to guys from the project team at Porsche who have developed the car (and in fact all the previous GT3 range of 911’s), have a tour of the Human Performance Centre and then finally have a drive of the cars on the test track.

The chaps from the factory are a fascinating bunch of guys.  What really stood out was their complete enthusiasm for not only their own cars, but for driving as a whole.  I spent the most time with Andreas Preuninger who was the project manager behind the GT3.  He’s a really good guy and had some great stories about his time at Porsche.

Andreas Preuninger

Over the years he and his team have managed to convince their accountants and management that their desire to create ever faster Beetle shaped cars isn’t just a flight of fancy.  In the process they’ve almost created a niche of their own for extremely focused, hardcore road and track supercars.   Whilst the sales teams doubted they’d be able sell the first 200 cars they planned, the last version of the GT3 sold to upwards of 5000 customers.

The latest 997 GT3 Generation II that we went to see really is a fantastic bit of kit.  There’s an incredible amount of thought and detail that has gone into making the car not only go a little bit faster, but feel better for the driver.  As an example of the levels Andreas and his team go to in order to find performance, you only really have to look at the effort put into just the engine mounts.

The engine in a car is one of the single biggest masses, so in a race car you fix the engine solidly to the chassis to stop it moving around as the car changes direction.  Any movement can unsettle the car making it harder to drive on the limit.  The disadvantage of this that there’s nothing to isolate the noise and vibration from the engine, so in a road car you just can’t get away with it.  Usually road cars use rubber engine mounts to soften the noise, with high performance cars using harder rubber to help keep the engine in check.  Even so, according to Andreas the even in the last GT3 the engine moved up to 15mm under load, and as it weighs 300KG that’s quite a bit of momentum.

The new GT3 uses engine mounts that are built using a magnetorheological fluid.  Essentially that’s an oil that has magnetic particles suspended within it.  By applying a magnetic field to the fluid its viscosity can be changed from thin (and therefore soft) to thick (and therefore hard).  This allows the car to sense when it’s experiencing high g-forces and stiffen up the engine mounts accordingly.  From what was said the engine now rarely moves more than 2mm from its ideal position, whilst also reducing unwanted noise when driving normally.

The driving part of the day was really eye opening for me.  Whilst I’ve done quite a bit of track driving in the past, that’s always been in my Elise so I wasn’t really too sure what to expect from the big, heavy 911.  Whilst I knew it was going to be very quick in a straight line, I have to admit I was very surprised by just how much speed the big car could carry once you pointed it into the corners.   You can tell there’s a fair bit of extra mass to move around, but it feels so stable and secure when you ask it to change direction it was never a problem.  Quite why I thought it wouldn’t be as capable as it was I don’t know, I guess I should have believed the hype!

One particular surprise was the electronic stability control systems.  Being a 10 year old Lotus my car’s lucky to have a radio, so the idea of driver aids is something a little alien to me. 

Stability control monitors what each wheel is doing at any one time, and uses this information to detect if the car experiences understeer or oversteer .  If it realises that something out of the ordinary is happening it can apply braking to each wheel individually to help the driver gather it up.  It’s a great aid to safety, but if you’re on track having fun it can get in the way by stopping the car doing what the driver wants.  I thought Porsches PSM system was very good indeed.  Even on the normal setting it allows a fair amount of slip, and with the sport mode on it gives you a serious amount of room to play before helping out.  It’s a world away from the systems I’ve experienced before with Mercedes that stop you doing anything interesting with the car.

So all in all I had a great time, the driving was fantastic fun but it was great to be able to chat to the techie guys behind the cars.  I guess it was quite a brave decision for Porsche to allow us lot in to quiz their guys and give their cars a good thrashing.  From what I understand it’s the first time that an event like this has been opened up outside of the motoring press and selected customers, so it was really quite a privilege to attend.  The Drivers Republic chaps are doing a great job building a community around their site, and whilst I originally had some doubts about how well a magazine would translate online, it really works well.  It’s great to see them working to get Porsche engaged with their community and from what I saw yesterday it can only do them a world of good. 

The enthusiasm of the factory guys was infectious, and just what I think petrolheads want to hear.  It was a completely different Porsche to the one you might expect, and from my limited experience very different to the one you see in your average dealership – sorry Official Porsche Centre (with a few exceptions to be fair).  Lets hope both Porsche and DR can do more events like this, and maybe even get a few more manufacturers involved. 

Right… I’m off to buy to lottery tickets!

What’s happening in Formula 1?

Saturday, June 20th, 2009

F1 Fight 

If you’re a fan of F1 you couldn’t help but to have heard about the current fuss in Formula 1.  With eight of the biggest teams proposing to split from F1 and setup their own championship, it could be the end of F1 as we know it.

So what’s all this about?  Well F1 as a sport is governed by the FIA.  They set the rules for the sport, both sporting and technical.  Over the last couple of years, the FIA have embarked on a number of initiatives to try and cut the cost of the sport.  This started by setting minimum lives for parts like engines to reduce the number the teams need over the course of the season, but recently have evolved into an opt-in cap on the teams budgets.

With F1’s costs so high, and with the world in the midst of a recession a budget cap seems almost sensible surely?  As with all things it’s not quite that simple.

For many F1 is not just about the skill of the drivers, but also the innovation and technology behind the cars and teams.  And it’s this that attracts the big manufactures for the sport.  It’s a fantastic way of showing the world that they’re company – or their brand – is up there with the best of the best.  It’s an exclusive club, and even if they’re not near the top of the grid, participation alone implies a level of skill and commitment that others aspire to achieve.

For the teams to succeed they’ve built up hugely capable organisations to design and race two cars each year.  If they were to cut their budgets from what can now be as high as £400million to the £40million being proposed, it would tear the heart out of the big teams.  It’s hard to see how such a huge organisational change would greatly affect their ability to develop and race competitively in the short term.

In addition to this, as a sweetener to adopt the budget cap, those teams that do will have greatly relaxed technical regulations.  These would allow the capped teams to employ movable front and rear wings and engines with no rev limit.  Movable aerodynamics alone could be worth more than 2-3 seconds a lap, so cars running on the current fixed regulations would be at a huge disadvantage.

Alternative cost saving measures and regulations that have been proposed by the teams themselves have been rejected out of hand by the FIA.  The teams and their backers are quite rightly angry about this, after all they invest huge amounts into F1 and feel their views should count.

Whilst the smaller independent teams like Williams have embraced the cap – after all F1 is their soul business – for the some of the teams the new proposals are a nightmare.  To field a competitive car they would need to adopt the new technical regulations, but in the process of doing so would need to compromise some of the core values that make them compete in F1 in the first place, and dismantle large parts of their organisations.  If you add to this the financial assistance that’s being offered to new teams that join F1 under the new capped regulations it’s clearly not looking like a level playing field.  We would end up with two classes within the single championship.

In response to the FIA’s plans  the big manufacture teams, under the banner of the Formula One Teams Association (FOTA), have rejected the changes and are threatening to leave F1 and setup their own championship in competition to F1.

This is something that has been threatened before, and indeed not that long ago they proposed the Grand Prix World Championship (GPWC) as an alternative series, even getting so far as doing all the detailed financial feasibility planning.  This was only shelved after Ferrari were offered a deal they couldn’t refuse, and the resolve of the teams dropped off.  They now seem to be dusting off those old plans and preparing to set up a series for 2010 – no small challenge!

Could they succeed?  Setting up a championship would be no simple task, but there are a few things that could work in their favour.  The fans will probably follow the teams and drivers that they know and love.  With the FOTA teams promising a series with open governance, stable rules and a focus on the fans with cheaper tickets they will surely keep a big chunk of their current following.  And with the fans will follow money from TV and sponsorship.

Clearly the best outcome would be for the FIA and FOTA to resolve their differences and allow F1 to continue in it’s current form.  If that can’t happen however, I honestly doubt F1 under the FIA will thrive without the big teams and drivers like Ferrari and McLaren.  An alternative series that has the teams and drivers from the current F1 season but under a new title would probably do ok.  After all what’s in a name?  Certainly it’s a huge challenge, and it wouldn’t surprise me if any 2010 season was a little light on the number of races, but FOTA would have many of the ingredients needed for success.

F1 going back in time, Lotus and Brabham in 2010

Sunday, June 7th, 2009

Lotus49

The FIA’s cost cutting budget cap for F1 has spawned many different views and arguments, but the changes are certainly bringing some interesting news for the 2010 season.

One of the great things is that a few of the great names names from F1 history are returning.  So far we have Brabham and Team Lotus both with entries for next year.

As a bit of a Lotus geek, the Team Lotus entry is particularly interesting, for me at least.  Essentially the Litespeed F3 team posted an entry for the 2010 F1 season and have secured the Team Lotus name for their efforts.  At first that might sound a bit strange but Nino Judge and Steve Kenchington, the team principle and director and engineering are both ex-Team Lotus so hopefully the name is safe in their hands.  What’s more they’ve based the team in Norfolk which is Lotus’s traditional home.  With Mike Gascoyne on board they’ve got the makings of a pretty good team there.

The Brabham entry is a little less straight forward with the entry from Franz Hilmer using the Brabham name possibly being contested by the family of Jack Brabham

Now if only Tyrrell would turn up we’d almost have a full set!

So what is a diffuser and what does it do for an F1 car?

Sunday, May 3rd, 2009

Since the 2009 F1 season started in Australia, there’s been a new order on the grid.  This year the sports technical regulations were changed, particularly those dealing with aerodynamics.  A few teams have got the march on the others by interpreting the rules in a different way, and have developed faster, better cars.  The old guard of McLaren and Ferrari are on their back foot, whilst teams like Brawn find themselves leading the championship.

If you believe the press this change of form has been down to the cars diffusers.  But what are they?  Most reports simply say that diffusers generate downforce, but strictly speaking that’s not really what they’re for.

Having had a few conversations about this recently I thought I’d attempt to write an explanation of what a diffuser does.  I’m not exactly an aerodynamicist, but hopefully this will make sense!  Right… so a few basics… sorry if they’re obvious! 

Ultimately a cars performance is dictated by it’s tyres.  The more friction or grip they have with the road, the faster a car can corner, accelerate and brake.  There are many weird and wonderful ways to get the tyres themselves to grip better, from compounds of rubber to their internal construction.  One simple way to increase grip though is just to push them onto the road more.  Sounds obvious eh?  Of course you could do this by adding weight, but that would compromise other aspects of the car’s performance.  The more mass a car has the more energy that is needed to accelerate it and keep it on the road, so really you want a way to push the car down, but without adding mass.  That’s where downforce comes in, using the airflow passing over – and under – the car to push it down into the road.

An important idea to understand when thinking about downforce is the Bernouilli Principle for fluid dynamics.  In short all this says is that the faster a fluid flows the lower its pressure.  In our case, the fast that air is flowing over the surface of a car, the lower it’s pressure.  (This is a vast simplification, but in general true.)

An example of this in practice is an aeroplane wing

Airflow over a wing

Airflow over a wing

A wing is shaped so that the air flowing over the top of it is faster than the air flowing under it.  The faster moving air has a lower pressure than the slower air, which generates an upward force that makes a plane fly.

In many forms of motorsport wings are used to generate a downward force to push the car onto the road.  In doing this huge amounts of downforce can be created.  But wings aren’t the  only way of achieving this. 

How about using the other surfaces on the car?  If you can make the air under the car flow faster than the air over it, the car itself would generate downforce.   Of course the airflow around a car should be as smooth as possible to avoid drag that would slow the car down, so the best route to achieving our goal is to accelerate the air under the rather than slow down the air over the top. 

The next principles to consider are the Conservation of Mass and Venturi Effect.  These principles are quite hard to explain (for me at least!) but can be demonstrated using the venturi tube below.

VenturiTube

As the air passes through the tube it meets a narrow throat through which it must pass.  The amount of air that enters through the inlet must be the same as the amount that exits at the end, so to pass through the throat the airflow must accelerate, and by increasing in velocity it reduces in pressure.  Once through the throat the diffuser increases the diameter of the tube back to that of the inlet, and therefore slows the airflow back to its original velocity.

A practical example of a venturi tube in use is a carburettor choke, where the low pressure is used to suck fuel into the airflow and then into the engine cylinders.

So what has this got to do with downforce?  Well imagine that half of the tube was flat (as below).

VenturiTubeHalf 

The same still applies, the air in the throat accelerates and slows.  So if the flat surface was a road and the throat the underside of a car you would get low pressure under the car – just what we want.

For this to work the car has to have a flat underside, any interference in the airflow will slow it down. 

The closer the car is to the road the faster the air will have to travel, hence the desire to run cars as low as possible.  One thing to consider here though is that whilst the airflow will go faster the lower the car, air still has to be able to get under it.  At some point the car will be so low that not enough air will pass under the front lip and the effect will stall, leading to a drop in downforce.  This is a particular problem under braking when the front of the car will dip towards the road.  If it drops too far the floor will stall and the driver will experience a sudden drop in grip just when he needs it.  This was what the active suspension of a few years ago was intended to avoid, it actively managed the suspension to keep the ride height at an optimum level.

Another effect of having lower than ambient pressure under the car is that air will leak in from the sides reducing it’s effect.  This is a real problem and one that on the old Lotus 78 and 79 race cars was solved by running skirts along the side of the car to stop air getting in.  Skirts are now banned, but other techniques have been adopted over the years such as creating vortex’s along the sides – but that’s all a bit off topic.

So if the flat floor generates downforce why have the diffuser at the rear of the car?  After all the more flat area you have the more downforce you’ll get. 

The diffusers purpose is to control the way the airflow at the back of the car decelerates back to its normal velocity.  So it less about creating downforce, it’s actually an essential part of the venturi whose purpose is to slow the airflow by increasing the space between the road and the underside of the car.  This allows the pressure to rise back up to ambient so that the airflow leaves the underside of the car as smoothly as possible decreasing drag that would slow the car down.  Having said that, the pressure in the diffuser will on average be lower than ambient, so it will create some downforce, but as a side effect.

A common misconception, and one that I made before I read a book about aerodynamics, is that the diffuser expands the air to produce low pressure.  This isn’t the case as it would require the airs density to change, and in an open system like the underside of a car a diffuser wouldn’t be able to do.

So how are Brawn and the other teams getting such an advantage?  Well by interpreting the aero rules differently they have been able to build diffusers that are much more efficient than their rivals.  By being able to start their diffusers earlier they are able to run them up closer to the upper bodywork of the car, and importantly closer to the rear wing elements.  The low pressures of the underside of the rear wing and diffuser interact and increase the effectiveness of each other.  There’s some really good information on the specific differences between the Brawn/Toyota/Williams cars and the others in the FIA’s explanation of their appeal ruling here.

A good book on this subject is Competition Car Aerodynamics: A Practical Handbook by Simon McBeath.  

New Donington F1 Circuit

Thursday, February 12th, 2009

Last year good ol’ Bernie announced that the British Grand Prix would be moving from its home at Silverstone to Donington.

Donington is a great circuit, and hosted one of the most exciting first laps I’ve ever seen back in 1993 (check it out below).  To handle a modern GP however it was always going to need a heap of development.

Over on the BBC News site today they’ve got a video from a simulation of the new track layout.  It’s looking pretty good so far, and from what I hear work is already starting on the changes.

Here’s that first lap I mentioned…

Ayrton Senna’s first lap of Doningtion at the 1993 European GP

 

Breakfast Club!

Wednesday, January 21st, 2009

Those fantastic chaps over at Goodwood have just announced the calendar for this years Breakfast Club.  If you’ve not heard of the Breakfast Club (not the film with Molly Ringwald), on the first Sunday of the month the Goodwood Motor Circuit hosts a free event where you can turn up, grab a tasty bacon sandwich and have a good look around some interesting cars, bikes and planes.  It’s a bit of a show-and-tell session so if you happen to drive something that matches the days theme your car can be one of the exhibits.

SC_Sunday_001_Goodwood_BC_01-06-08_Paul_Melbert

This years calendar is shaping up like this:

1 March ‘Mini Mayhem – for all Small Sporting Runabouts’
Celebrating everything from the original Mini to the archetypal hot hatch and modern Supermini, plus RV sporting light aircraft.
5 April ‘Fabulous Family Favourites – from Fords to Flaminias’
Any practical collector’s car with room for all the family, plus four-seater and fixed gear aircraft.
3 May ‘Everything But The Car – from Bikes and Buses to Tractors and Trucks’
All forms of motorised transport except conventional passenger cars. Motorcycles, scooters, three-wheelers, campers, light and heavy commercial vehicles, off-road workhorses, other utility vehicles and even aircraft are all welcome – nothing is too bizarre!
7 June ‘Supercar Sunday – the Ultimate Performance Machines’
Mouth-watering (and mostly mid-engined!) ultimate performance cars and exotic superbikes, plus aerobatic aircraft.
28 June ‘Performance Car Legends – post-1970 Driver’s Cars’ Sports and GT cars from the 1970s to the present day, from Jensen Interceptor to Ariel Atom, as well as Lotus, Caterham, TVR, Porsche and many more, plus retractable aircraft.
5 July Not held due to Goodwood Festival of Speed
2 August ‘Soft Top Sunday ­– a Taste of the British Summer’
Roofless cars of all ages, shapes and sizes, plus all open cockpit aircraft.
30 August ‘Thoroughbred Sunday – the Quintessential Classic Car and Motorcycle’
Any pre-1966 road vehicle or aircraft in the spirit of Goodwood circuit’s golden days.
6 September Not held due to Goodwood Revival preparations
4 October ‘Maserati Magnifica­– a Tribute to the Trident and other Italian Icons’
For all Maseratis and any other Italian collector’s vehicles, from a Lambretta to a Lamborghini, plus Continental aircraft.
1 November ‘Souped-up Sunday – Modified and Custom Vehicles of all Ages’
Everything from hot rods and custom cars to contemporary urban cruisers, plus home-built aircraft.
6 December ‘Breakfast Club Christmas Cracker’
Any cherished car or aircraft, preferably with a heater and plenty of boot space for your Christmas shopping. Yule be glad you came!

I live up the road from Goodwood so I’ve been to quite a few Breakfast Clubs over the past couple of years, they’re a pretty good way to spend a Sunday morning – especially if you follow it up with lunch at the Fox Goes Free!