January 2013

21 January 2013

It's been pretty uneventful these past few months. I drive the car to work a couple of days a week, and nothing has really failed. But I have started picking away at a few items recently.

Some time back (last Spring?) in an effort to increase the visibility of the car from behind, I adapted a third brake light from a later model 911. (You can see it at the bottom of the window in the rear wiper picture on the Oct. 2012 page.)

While that unit did what I wanted it to do, the adapted mounting method didn't hold up well. So earlier this month I replaced the big light with a small LED strip mounted at the top of the window. While the LED strip is smaller, being mounted at the top of the window it should be at least as visible, and the mounting method for the small, light-weight light should be more secure.

Brake light picture

In another example of re-working an earlier job, I replaced the voltage regulator again this past weekend. Regular readers may recall that I had to do that right after I bought the car (Nov. 2011). While the earlier replacement fixed the no-charge problem, a few months back I noticed that all the lights in the car flickered (several times per second) most of the time. Research indicated that the only likely cause was a slowly reacting voltage regulator.

Since I was unsure about the cause last time, I had the alternator checked at a local rebuilder. When they determined it was the regulator, I had them replace it, but I did not have any choice over the brand of regulator, so the quality of it was unknown. This time I knew the regulator was the likely cause, so I did it myself, purchasing a new one made by the original supplier to Porsche (Valeo). Replacing the regulator requires removal of the alternator, but since I had already done that once, the job went smoothly and quicker than expected. And the new regulator did fix the flickering lights, the output voltage is much more stable now.

Last for this month, I recently re-installed the car's original catalytic converter. The previous owner had replaced it with a small muffler (known in Porsche circles as a "pre-muffler") to enhance performance. These pre-mufflers are a few pounds lighter than the catalysts, less restrictive, and are said to give an increase of a few horsepower, mostly at high RPM. The downsides are increased emissions and the smell of unburned hydrocarbons from the exhaust. Since these old cars are now exempt from emissions testing most everywhere but California, and many Porsche owners will do anything to gain more power, pre-mufflers (and their close relatives, the louder catalyst bypass pipes) are popular accessories.

But I don't need those few extra ponies for how I use my car. Indeed, I rarely run the car hard enough to get to the higher RPMs where the pre-muffler would have any effect. So to me there are no benefits to out-weigh the downsides of smells and more emissions.

That's why I put the catalyst back on. I'm going to drive it a while to verify that I can't tell any difference (seems to be the case so far), and if so I'll sell the pre-muffler to finance other things on the car.

Continued in February...