I did an automotive electronic installation the other day. It’s a particular job I have done many times before – installing driving lights on a vehicle – but I came across a problem I’ve never before experienced.

After bolting a pair of Narva 175 driving lights onto the front of my wife’s Skoda Roomster, I decided to buy another pair for my own car. Simply, considering the cost of the Narvas, I was very impressed with the quality of the illumination upgrade on the Skoda. In addition to a relay, switch and terminals, the Narva package contains both wide and narrow beam lights; I found the effective combination of spread and penetration makes a huge difference to night-time driving safety. 

And not just safety – I’ve done a few long distance drives in the Narva-equipped Skoda and it’s a lot les fatiguing driving with good lights.

On my Honda the installation was always going to be relatively difficult. As with many cars, the Insight has no real mounting spots for additional lights. The approach taken by many – install an adaptor held in place with the number plate screws – didn’t do a lot for me so I searched on the car for places where brackets could be mounted. In the end I welded together a square tube assembly that sits just in front of the radiator but behind the bumper, held in place with welded-in spacers and bolts that pass through original sheet metal holes. The lights themselves mount on 10mm threaded rod through thick flat steel brackets brazed to the square cross-tube.

I also took some pains with the wiring, choosing not to use the relatively thin wire provided with the kit. Instead I ran thick, dual-core cable from each of the lights back to the Narva-supplied relay that I mounted on a new bracket located close to the battery. I added a 20 amp blade fuse in a holder and triggered the relay from the high beam headlights.

Being a slow worker and taking my time, it took about a full day.

That night, I went out to aim the lights. Driving around the country town in which I live there are plenty of dark streets and country roads to use – things were going smoothly until I suddenly found a major problem. After the driving lights had been switched on for a few minutes, they wouldn’t turn off! I had to actually pull over, lift the bonnet and physically tap the relay to get the lights to extinguish.

That made me unpopular with oncoming traffic and so after this had occurred a few times I gave it up and went home.

The next day I measured the voltage across the relay’s coil’s contacts. Relays disengage at a much lower voltage than they pull-in (for example, a 12V nominal relay might not disengage until the voltage has dropped to 3V) and I wondered if there was a residual voltage keeping the relay engaged. However, a check showed that while there was a voltage on the wire (even with the high beams off), it amounted to only 0.3V – and any 12V relay should be turned off at only 0.3V!

So what was going on? I swapped the Narva relay for another relay I had in my spare parts drawer and the new relay operated without any sticking problems. So the original relay was the issue.

I then pulled open the Narva relay to find that, on the contacts, there was a tiny but obvious burn mark (arrowed). The relay contacts, despite being quite large in area (as befits a 30 amp relay) were in fact touching at only a tiny spot. The contacts were literally welding themselves together!

That’s pretty weak in a brand-name driving light kit. So while I still admire the light output, I think if I fit any more of these lights, I might supply my own relay…

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One of the automotive ideas that seems to be taken as gospel is that the chassis and suspension arms should be stiff – that is, neither should deflect when subject to load. In fact, if I’d had a dollar for every time I’ve read that ‘good handling depends on a stiff chassis’ I’d be richer than I am.

But I think that, especially for ultra-light vehicles, this notion is simplistic.

Firstly, every structure deflects under load. That deflection may be small, but it occurs. Even the Sydney Harbour Bridge has an allowable deflection under maximum load of 4.5 inches (114mm) in the centre of its span.

Secondly – and more importantly – chasing reduced deflection will add substantially to weight. The corollary of that – the lightest possible vehicle will always have deflections.

Finally, not all deflections are bad.

Let’s start off with the last. Most cars use rubber bushes that are designed to have differing stiffnesses in differing planes. One reason for this is so that wheels can move fractionally backwards when they meet a bump, reducing harshness. Another reason is that in some (many?) suspensions, if the bushes didn’t have ‘give’, the suspension would lock up solid during travel.

Passive steering suspension systems – the first well publicised was the Porsche ‘Weissach’ axle of the 928 – often use bushes that deflect, or links that give an effectively ‘non-stiff’ suspension in some planes.

Going backwards to the second point, getting rid of measurable deflections in chassis and suspension arms will result in a major increase in weight. In ultra-light vehicles (eg those powered by human legs, a small petrol motor or an electric motor), and especially those made from chrome moly steel tube, deflections under major loadings are often able to be seen by eye.

For example, the peripheral torsional wind-up of a front suspension arm might be 5mm or more under maximum braking, and under max cornering there might be 3 or 4mm of bending in wheel supports. In a human powered vehicle (HPV) with a recumbent seat and front pedals, boom flex under maximum pedalling force can often be 10mm or more.

So does all this matter? In some cases (like boom flex, that subtracts from the power available from the rider), yes it does.

But in other cases – not necessarily.

What is required is that the structure is never stressed to the point of failure, and that the vehicle dynamics remain consistent.

I have been musing over these ideas in the context of the HPV I have been building.

I know that under brakes the beam front axle will torsionally wind-up, reducing the static castor of the front, steering wheels. That might lead to steering dartiness under brakes – but for the fact that when the front brakes are in action, the vehicle has some dive, that in turn causes a rapid increase in castor.

On my previous recumbent trike design (called the Air 150), I had difficulties in getting rid of steering twitchiness. The problem felt all the world like toe-in bump steer, where I’d put on some steering lock, the machine would roll slightly – and the outer wheel would toe-in, giving a sharper steering response than requested. That was the theory – but I found this odd when on the workshop floor, toe-in on bump was small or non-existent.

But I now wonder if the outer semi-leading suspension arm wasn’t flexing sideways a little with the sudden application of the lateral force, which in turn caused “turn-in steer” as the suspension arm and the steering tie-rod flexed through different arcs.

Certainly, at the very early stage of testing I am at with my current HPV ‘Chalky’, there’s no steering twitchiness on turn-in – and the front suspension is laterally much stiffer than the previous design.

(I fixed the Air 150’s twitchiness by setting the suspension up with either static toe-out, or toe-out on bump – but the problem returned when carrying really big loads. If the arms were bending laterally, perhaps it just needed even more static or bump toe-out to compensate?)

And I guess that’s the point. In a vehicle – any vehicle – there will be dynamic variations that don’t match the static settings.

(Many years ago, I remember having a wheel alignment done on my Daihatsu Mira Turbo. I was happy with the alignment machine’s read-outs – but then the mechanic got me to sit in the driver’s seat. On that simple car, the suspension settings immediately changed!)

If the weight of the vehicle has been has to be kept to an absolute minimum, and so major deflections occur in the suspension and frame, the trick is to optimise the direction of those deflections so that they don’t subtract from – and possibly even add to – the on-road experience.

That’s a very different notion to ‘keep everything as stiff as possible’.

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I feel like one of the first pilots of jet-powered aircraft. They immediately knew that they were flying the future: there could be no going back to pistons and propellers.

Today I drove the car that, for me, spells the end of the piston engine for performance cars.

The car was the all-electric Tesla, and its performance – and the way it achieved that performance – was just so extraordinary that I am almost lost for words. That a start-up car company has created such a vehicle is simply unprecedented in the last century of automotive development.

For the Tesla is not just a sports car with incredible performance (0-100 km/h in the fours) but also a car that redefines driveability. Simply, it has the best throttle control of any car I have ever driven.

Trickle around a carpark at 1000 (electric) revs and the car drives like it has a maximum of just a few kilowatts available. It’s the pussy cat to end all pussy cats: Grandma could drive it with nary a concern in the world. Put your foot down a little and the car seamlessly accelerates: heavy urban traffic, just perfect.

But select an empty stretch of bitumen and mash your foot to the floor and expletives just stream from your mouth as the car launches forward with an unbelievable, seamless and simply immensely strong thrust.

There are no slipping clutches, no flaring torque converters, no revving engines, no gear-changes – just a swishing vacuum-cleaner-on-steroids noise that sweeps you towards the horizon. The acceleration off the line and up to 100 km/h or so is just mind-boggling – especially as it’s accompanied by such undemonstrative effort. The car will do it again and again and again, all with the same phenomenal ease that makes this the winner of any traffic lights grand prix you’re ever likely to meet.

And it’s not just off the line. Want to quickly swap lanes? Just think about it and it’s accomplished. 

In fact drive the car hard and you start assuming that this is the only mode – outright performance. But then enter that carpark, or keep station with other traffic, and you’re back to driving an utterly tractable car – in fact, one for whom the word ‘tractable’ is irrelevant. Combustion engines are tractable or intractable; this car’s electric motor controller just apportions its electron flow as required, in an endlessly seamless and subtle variation from zero to full power.

It’s not just the acceleration that is revolutionary. The braking – achieved primarily through regen – has the same brilliant throttle mapping, an approach that immediately allows even a newcomer to progressively brake to a near-standstill at exactly the chosen point.

A seamless, elastic and fluid power delivery that no conventional car can come remotely close to matching; a symphony on wheels to be played solely with the right foot; an utterly smooth and progressive performance than can be explosive or docile, urgent or somnambulant – literally, a driveline that completely redefines sports cars.

There’s no going back – my driving life is now changed forever.

Footnote: the Tesla drive was courtesy of Simon Hackett of the ISP, Internode.

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Perception of any crisis in world affairs has always followed much the same pattern.

Those who say it isn’t happening and never will happen; those cautious but observant who say it might happen; those early adopters who say it is happening well before a majority agree; and those who like to see it unambiguously demonstrated before acknowledging it is actually happening.

Or – and this is really important – not happening.

Trouble is, at the ‘it might happen’ stage it’s difficult to decide on the right course of action. Do nothing and any action might be too late.

Or, conversely, do nothing and in fact the action might later prove to have been correct.

Think CFCs in aerosols and the ozone layer for the first; think Y2000 bug in computer software for the second.

And the eminence of the ‘early adopters’ counts for little: remember the 1970s predictions of a world overpopulation crisis, and how widespread famine would result in a catastrophic reduction in the population by the year 2000? Despite some very highly credentialed experts arguing vehemently – and with apparent logic – that we were doomed, it didn’t happen.

And now to global warming. 

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Hybrid car drivelines can be characterised as being of series or parallel designs.

In a parallel hybrid, either of the two power sources can drive the wheels. In a petrol/electric parallel hybrid, that means either the petrol engine, or the electric motor, can propel the car.

In a series hybrid, one power source drives the other that in turn propels the car. For example, in a diesel electric series hybrid, the diesel motor might drive a generator that charges batteries. These batteries in turn power the electric motor that pushes the car along.

The best known of all hybrid cars, the Toyota Prius, uses a series/parallel design; most of the time the electric motor and the petrol engine drive the wheels directly, although the petrol engine can be used to drive a generator that in turn charges the battery pack.

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It’s happened only a few times in my life, and each time it’s been a salutary experience.

One occasion I can remember is a long time ago. I was in junior secondary school and was heavily into solar energy. I’d constructed my own solar water heaters, solar pie warmers and other bits of gear. I knew about meridian altitude, I knew about flat plate collectors and thermal mass.

I’d also read all the books I could get my hands on that dealt with solar heating and knew inside-out the (handful) of books on the topic in the school library.

In fact I was pretty smug about my level of knowledge and understanding.

Then a new book came into the library. I can even remember its size and shape – it was a book long in landscape direction and had soft covers. It was also quite thick.

I remember I picked this book and started looking through it with little interest. After all, I already knew everything about solar energy…

But, all of a sudden, I went very quiet and became intent. I was just about to discover a whole new world of solar energy complexity and relevance; my learning on the subject was going to progress hugely.

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A press release worth reading:

Limited Edition Tesla Roadster Available Spring 2009

Hi Tesla Enthusiast,

When you last contacted us we were selling our high performance, 100% electric Tesla Roadster only in the continental United States. We are now selling special limited edition Roadsters into Europe, starting in 2009. We originally planned on expanding into Europe much later, but several factors have allowed us to accelerate our expansion. Check out VP of Sales, Marketing and Service Darryl Siry’s latest blog announcing the details and our April 9th press release.

This special limited edition will sell for €99,000 for a fully loaded car, to be delivered beginning in the spring of 2009. Similar to our early customers in the US, Europeans who reserve the car early will receive a special Signature edition version of the world’s most exclusive high-performance vehicle. For details on reserving this special edition Roadster contact Tesla at eurosales@teslamotors.com or call +1 650-413-6200.

In case you missed it, the Roadster has recently been reviewed by: AUTOBILD, Car & Driver, Automobile, Motor Trend, Road & Track, and Auto Week magazines – check out the reviews by clicking on the links.

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One of the aspects I like most about hybrid and electric-powered vehicles is regenerative braking.

Regeneration braking (“regen”) occurs when the electric motor is used as a generator, so charging the battery and in turn slowing the vehicle.

Regen is important for energy-efficiency – the energy that would normally be wasted in friction braking is instead utilised. In many driving conditions this can result in a substantial improvement in fuel economy (hybrids) or driving range (battery electric).

However, I like regen most because it is really effective from a driving perspective.

Unlike friction braking, the faster that you are going, the better regen works. The faster-moving vehicle has more potential energy that in turn can be turned into more electric energy. That’s the case with friction braking as well (the potential energy is higher so more heat energy can be generated) but since conventional brakes reduce in effectiveness as they are required to do more work, the feeling is not the same.

Regen braking can feel like the ‘inexorable giant hand’ pulling you back, all with smoothness and a degree of control that is impossible to obtain with friction brakes.

And let’s look at the subject of control for a moment.

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Unusually, in this blog I want to refer you all to the AutoSpeed article that was published today. As I have written above, I think it’s probably the most important article that we’ll publish this year.

So what’s it about?

In short, the article is based on a paper written by Dr Andrew Simpson when he was working for the Sustainable Energy Group at the University of Queensland. His paper looks at a huge number of alternative fuels and drivelines, concluding which are the best from both energy efficiency and greenhouse gas emissions perspectives.

Andrew has given us permission to use major excerpts of the paper, and in fact went through it again to ensure that his conclusions are current. The full paper can be downloaded from the link at the end of the article.

His is a detailed ‘well-to-wheel’ study, where the environmental costs of producing the fuel and the efficiency of the cars using them are evaluated. Even better, they’re all benchmarked against a real car, the Holden Commodore. Even better again, the alternative fuelled cars are modelled to have the same range and performance as the Commodore.

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