The importance of being well-lit.

Posted on October 19th, 2003 in Opinion by Julian Edgar

Inevitably anyone who works (in paid employment) and also works on their own car (for fun) will spend a lot of time twirling the spanners in the middle of the night. And that means that – again inevitably – they’re going to have invest in some decent lighting. (It always puzzles me when I go into poorly-lit workshops – you can literally see the mechanics feeling around for things that – with decent lighting – would be obvious.)

As with most houses around here, mine is built on stilts and so the de facto workshop is located under the house. It’s dim under there, even in the middle of the day. The lighting that came with the house comprises two double fluorescent battens – for an area of about 60 square metres. Not good. I rigged some Portaflood-style 150W directional incandescent bulbs over my workbench, but the rest of the space remained pretty dark.

So what to do? I was undecided… so did nothing for two-and-a-half years.

An important lesson in the way in which the different parts of the car are interconnected.

Posted on October 5th, 2003 in Opinion by Julian Edgar

As described in stories that we are running in AutoSpeed, over the last few months I have modified my 1988 Maxima V6 Turbo to have increased boost (and less wastegate creep), an intercooler, cold air intake and cat-back exhaust. Nothing wildly exciting or unique about that lot (although the prices for which the mods were achieved was pretty groundbreaking!), but even so I have noticed a few outcomes I never realised would take place. And that’s despite having in the past owned many modified turbo cars…

The Maxima is instrumented with a fast-response LCD temp probe placed in the intake system just before the throttle body. It’s a device that I have also talked about before, but it’s worthwhile stressing that seeing what is really happening beats all the theories in the world, hands-down. (When you’re reading web discussion groups, watch for the posters who write ‘I measured this’ or ‘The stopwatch showed that’ or ‘Here are the dyno curves’. The number of people who just theorise – often incorrectly – is bloody incredible. A few measurements and you know what is happening!)

The first thing that I noticed is that with the anti-wastegate creep boost control in place, the intake air temp gets higher, sooner. That is, the relatively small intercooler is pushed harder because the temp of the air feeding it is hotter, earlier.

As a turbo compresses air, it inevitably heats it. How hot it gets depends on the efficiency of the compression process – but even if the compressor were 100 per cent efficient, the air would still get much hotter than ambient. In the Maxima’s case – as with any other car running an anti-wastegate creep boost control – boost occurs earlier in the rev range. That’s exactly what you want – more boost sooner. But the corollary of that is that the intercooler load rises, even in normal point-and-squirt driving.