My two cars compare and contrast

Now that I am fully retired for a year now I have been heavily into upgrading the 2009 Westfield Megabusa and sorting out the gremlins from the initial build of the Sylva J15.

In terms of handling and acceleration the Megabusa is by far the best car. However unless you want a bike engine screaming in your ear all the time, with clunky gear changes in traffic, then the Sylva is currently the best car for the the road. I have come to this conclusion having driven both cars on and off the track for the last year.

The Megabusa started off the 2014 season, a pig to drive as I had never experience a BEC (Bike Engine'd Car) before. I could never work out where maximum revs were in time and never could decide which gear I was in. After solving various technical issues I eventually fitted a digital LED progressive rev warning indicator and a cheap gear indicator. These made a fundamental difference to the driving experience on the track.

The Sylva started off 2014 relatively unreliable due to various technical issues but fundamentally I could not get it to turn into corners properly (too much over steer). The brakes had no feel. Against advice I fitted a front ARB (Anti Roll Bar) and that transformed the turn in. I also upgraded the brakes by changing the master cylinder sizes.Latterly I began to enjoy the J15 even on the track.

I am constantly upgrading and modifying both cars relative to perceived problems either on the road or the track.

The Sylva can be found at: http://sylvabuild.blogspot.co.uk/
The Megabusa can be found at: http://westfieldbusa.blogspot.co.uk/

Westfield Megabusa - off side

Westfield Megabusa - near side 3/4

Both

I plan to track both vehicles this season 2015 I hope you track my progress.

Matt's alternator

Recently I received a string of emails about Matt's trials with the wiring in his (new to him Westfield SEIW) car. The emails adopted a more and more desperate tone titled "Bloody Alternator Light!".

The problem was with the alternator charging light. The battery appeared to be charging but no light to tell you it was. It was compounded by various bits wired wrongly, from day one I suspect. At one point I observed one of the wires between the alternator and charging lamp on the dash were not connected to each other and we could not identify where they were going (even worse). Matt had approached the problem methodically enough, sorting out this basic wiring problem behind the dash and even  buying a replacement alternator. Needless to say he eventually got so frustrated he took up my offer of help hence this blog. I tend to bog everything on these cars as they are so interesting (not to the wife of course). You never know the information might be useful to another enthusiast.

 I did an investigation by constructing the basic charging circuit including battery, alternator and lamp on my work bench. I turned the alternator using a Dewalt 300W drill driver and a socket (to simulate the engine). Using this method revealed both alternators faulty. The problem was the lamp cct output  produced by the internal electronics gave no pull down to earth for the indicator lamp.

We used the documents on the Westfield Word site for this alternator. The diagram on one section appears to be wrong. I suspect this could be the source of the problem. On a Denso alternator pin (1) is always switched live and pin (3) is always the lamp cct. The only pin that varies it's function is pin (2) which acts as an external voltage reference point on some models. In Matts case of course this inverted wiring caused both alternators to fail.

When checking out the alternators I found one of them was still partially working. It was giving 2mA constant current when idle and 0mA when wound up to speed by my Dewalt. This was good news to me as this can easily be converted to a correctly working charging lamp using a transistor and one resistor. In other words the transistor in the alternator had failed in such a way that the internal electronics was 90% still working save the pull down function.

I wired up a new pull down cct using the case of an old 3 pin Ford bleeper module and inserted the transistor as shown below, which I also had in my scrap box (I have some wonderful stuff in my scrap boxes).This resolved the problem entirely.

Just in case Matt needs to keep a record of the module wiring I have reproduced it here.

I have to thank Matt for a really interesting days fault finding on one of my favourite cars.