The joys of finding a single wire…

Posted on March 28th, 2004 in Opinion by Julian Edgar

Today I spent nearly six hours trying to find a wire. Odd, you say? Wasn’t there plenty of wire available at the local electronics store…cable, even? Well there was, but this particular wire was contained in the loom of a car. And the wire that I was looking for had a very specific signal on it. It was the speedo input on a mid-Eighties BMW735i.

It had all seemed easy enough…

Part of the very exciting range of DIY automotive electronics kits I am developing with www.siliconchip.com.au magazine is a speedo interceptor. It’s a small box of tricks that will let you adjust your speedo reading up or down, giving you the facility to not only correct errors but also make appropriate changes when the gearing of the car has been altered. The concept is easy – it’s just a frequency-altering device – but as always, actually developing the kit has been another ballgame altogether.

So the module that today I was trying to fit is actually the second prototype. The difficulties with the first design came about when it was realised that there’s a whole host of different design speed sensors, and if the kit was to have any pretence of being universal in application, it was going to need to be able to be configured to work with all those sensors. Not to mention, be happy working into the speedo or the ECU.

The first design came and went, then electronics designer John Clarke completed the second iteration. And it looks a beauty – you can digitally increase or reduce the speedo reading in 1 per cent increments, simply by turning two multi-position switches. So if you alter the diff ratio so it’s 10 per cent taller, you simply alter the speedo correction by the same 10 per cent.

A week of cars

Posted on March 14th, 2004 in Opinion by Julian Edgar

Our recent editorial trip to Melbourne (well, recent as I am writing this), resulted in Michael Knowling and me driving a huge variety of cars – literally, from a 512TR Ferrari to a Japanese Domestic Market grey-import Toyota Hiace Super Custom Limited. In between there was the incredible APS Stage III (Phase III? whatever…), a Lancer Evo 7 and a current model 4.6-litre factory blown V8 Mustang.

We’ll cover (or have already covered) all these cars in full AutoSpeed stories, but here are some of my thoughts…

The APS car is the most impressive straightline street performer I have ever had the pleasure of steering.

You’ll have already read about the car in AutoSpeed but I gotta reiterate that the APS Stage III Falcon XR6 Turbo is really Something Else. Here is a car that in traffic is literally as docile as any ol’ auto-trans XR6 T, but with the foot down even half-way, can obliterate pretty well every other car on the road.

Push the throttle to the floor and it’s a case of feeling yourself flung towards the horizon. Get on the gas at 100 km/h and the nose perceptibly rises, the boost builds and – whoosh! – you’re gone. From one hundred kilometres an hour to 200 kilometres an hour takes, well, about as long as to read part-way into this sentence.

Figures? We’ve already run them but to remind you, try 327kW at the back treads, a standing quarter in the mid-Elevens, and a predicted kit cost of about AUD$9000.

Shopping for rubbish

Posted on February 29th, 2004 in Opinion by Julian Edgar

One thing that I’ve always been happy to do is go through other people’s rubbish. Simply, it seems to me – and has always seemed to me – that if you can get something for nothing because it is being thrown away, and that item is of use, it’s a win for you.

So right from the time I first got mobile as a kid on a bicycle, I’ve been happy going through bins and scouring the dump. In fact, I well remember early Sunday morning jaunts through the industrial suburbs near where I lived. The trips weren’t random; nope, I’d use the Yellow Pages to find the factories likely to be throwing away the items I was after, consult the street directory to locate the premises, draw up a map, and then head out to find my treasures. And very often come home with just what I wanted.

All pretty logical for a 13 year old.

One local factory made furniture and each week in their skip were five or so 1 metre-square pieces of plywood. They all had an odd keyhole-shaped cut-out in one corner but apart from that, they were completely pristine. So every Sunday I went and collected them, bringing them home on the pushbike. Another factory made insulation, and for no apparent reason discarded batt after batt of fibreglass. Another threw away copper tube, and another often had reasonable sized sheets of glass. Since my interest at that time was solar energy, it wasn’t a great step to construct my own plate-type solar water heaters, low temperature food warmers, and so on.

Thinking back, all I had to actually pay for was a few cans of matt black spray paint and some woodscrews…

Logging temps

Posted on February 15th, 2004 in Opinion by Julian Edgar

Those of you who have read the series (starts at Using Oscilloscopes on Cars, Part 1 ) will be aware that we’ve recently been exploring the use of digital scopes with cars. As we said in those stories, if you’re doing any modification work that involves input and output signals, the only real way to see what you’re doing is with a scope. Putting my money where my mouth is, I recently bought a digital handheld scope – a Fluke 123 Scopemeter. I got it secondhand but in as-new condition – it’s a product that I have spent nearly two years trying to find at the right price…

In addition to its abilities to display waveforms, it can also be used as a paperless chart recorder. That is, it can plot by means of a line graph the level of a signal over time. Both the time and level parameters auto-scaled, so it doesn’t really matter if you’re logging something for 10 seconds – or 3 days. You can’t download the actual logged numbers from the meter but you can dump the graph itself to a PC. So the logging function of the Scopemeter isn’t as good as you’d get with an adaptor working into a PC, but because of its speed of set-up and ease of use, it’s more likely to be used in everyday measurements.

When you don’t have a workshop manual and the car’s very complex…

Posted on February 1st, 2004 in Opinion by Julian Edgar

Took on a big job the other day. Well, it was big for me. As I have discussed in another column (Driving Emotion), my partner recently bought a 1985 BMW 735i – and I was saddled with the job of fixing the things that didn’t work. Things like the electric seats (which I have covered in a dedicated story), the trip computer and the climate control.

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Road versus track testing of normal cars

Posted on January 18th, 2004 in Opinion by Julian Edgar

For years I’ve thought that magazines that test road cars on the track are deluding themselves. The conditions on a typical race track are simply so far away from real roads as to make the judgements gained on a track worse than useless. And I deliberately say ‘worse’ because in many cases I believe that the outcome of a process that involves track testing road cars – and then writing a road test on that car – can be very misleading.

A road car is a car designed for roads. You don’t test a Formula racing car by driving it to the local shops and seeing how many groceries can be fitted in, so why test the handling of a road car on a race track? Race tracks are invariably smooth, they have one-way traffic, they have run-off areas (which immediately makes a nervous car feel less twitchy!) but most importantly of all, the driver always knows exactly the radius of the next corner, the length of the straight, what the blacktop does following a crest.

Simply, on a track you’ll enjoy a car more inclined to oversteer, with much faster responses, and with quicker steering than would ever be pleasant – and safe – on a road.