my 73 Super only has a Speedometer and since I'm new to this car I can't tell RPM based on sound. I want to install a tach, but what sends the info TO the tach? what all is involved in this? Also, I have a 4 speed manual trans, what is the average shift points between the gears, in both RPM and speed....thanks!
Your speedometer should have little orangish tick marks around the dial, three in total. They mark the shift points for you. When your car is going that fast, shift. :)
the actual speed you are going when you shift varies depending on what year the car is from, due to changes in engine sizes and the gears. A decent rule of thumb is something like 15-30-45 (mph) for shift points. The engine is best kept between 2,000 and 3,500 rpm.
just drive around normally, it won't take you more than a day or two to get a good feel for when the car needs shifted. If the engine is getting loud and it won't accelerate any more, that means it's past time to shift up. If it studders and likewise has almost no power, that means it's past time to shift down.
the car is forgiving enough to let you make some mistakes when learning.
You need three wires to get the tach to function, +12 volts, a ground, and a wire from the points side of the ignition coil to the tach. The signal comes from the points opening and closing(or in the case of a pertronix, the electronic 'switch' turning on and off).
I installed a tach in my 74 super, I ran the wire through an existing hole on the drivers side fender well, which got me out of the engine compartment. I cut back through the hole that the shock mount bolt is accessed through and then pushed the wire into the same grommet as the metal brake line that feeds the rear wheels. From there you can run it along with the main wiring harness with some zipties. I pulled the twelve volts from the fuse panel, I basically probed the fuses with a voltmeter until I found one that went hot with the ignition on, and used that as the +12 supply for the tach. If you want to hook up the light, you can do that down there as well, just use one of the headlight feed fuses. You have to drop the fuse panel to make the connections, but I found enough open spades to make it easy to install with a few crimp connectors(but solder them, the crimps never hold up in the long run..) I bundled up the wires and fished them down behind the dash between the forward portion of the dash and the windshield. It's not the prettiest installation.
The super beetle does not lend itself well to additional gauges without a lot of work. I built a small bracket for my VDO tach out of some computer case expansion slot covers, I bent them to fit and gave them a coat of black paint. I mounted the bracket using the screw in one of the center dash vents. It basically rests on the forward portion of the dash, the bracket just keeps it from falling forward.
Chris
You have to run one wire(the signal wire) from the engine compartment to the tachometer. Go look at your coil, it has three connections. One big one in the middle, which is an igniton cable that goes to the distributor, one that gets 12 volts when you turn on the key(this one will come out of the main wiring loom on the drivers side of the engine compartment), and one that comes from the points in the distributor(usually a green wire) to the negative side of the coil. You must run an additional piece of wire from the engine compartment all the way to the tachometer. Hook it to the negative side of the coil along with the points wire. Usually there is an extra spade back there already on the coil for you use.
Chris
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