Volume 4, Issue 10
Last month I discussed the new In-Dash tachometer conversion kits being sold by Shiftworks®. Before I sat down to type my rant I sent off an email to Shiftworks to clarify some issues I had. The main issue was if these tachs would work with an aftermarket, multiple spark ignition system like MSD. The instructions that came with my MSD box explained how many tachs would not work with the ignition box unless an expensive tach adapter was used. At the time I wrote that rant, Shiftworks was not sure if it would or not.
For me, this was a big issue because it significantly raises the price of the tach if I also have to purchase an adapter to get it to work. Over the next few weeks, Herb from Shiftworks was extremely helpful in trying to get an answer. I was very impressed with him and Shiftworks customer service. What we found out from the manufacturer was that the internals were similar to those used on Autometer tachs. Autometer is one of the tach manufacturers that MSD says does not need an adapter. Herb then offered to send me a tach to test. This test will kill 2 birds with one stone as it will also clear up the issue if the 1971-74 tach will physically fit the 1975-76 dash.
I requested the 1971-74 tach with white numbers (part S517-W) to match my 1976 dash. When it arrived I was very impressed with the quality of the tach and the ingenious design. You see, the tach is in 2 parts to make it fit the small dash of 1968-76 Novas. One part is basically just the face and needle. The other part is a "shotgun shell" that contains the electronic brain of the tach. The two parts are connected by a 4 wire harness with a connector to separate the two. This made installation and future removal easier. It probably also makes manufacturing much cheaper as the same brain can be used for many different "faces" to fit numerous cars. (Shiftworks also sells tachs for 1964-65, 68, 69 and 1970-72 Chevelles). The brain is wired into the car with only 3 connections: 12v switched power (red wire), Tach signal (green wire) and a ground (black wire). This is identical to other tachs with the exception of no white wire for lights. This is because the lights already in the dash provide the illumination.
Before I tear apart my dash, I wanted to test the tach to see if it worked with the MSD box and to see how accurate it was. I temporarily wired it into the car along with the 3-3/4" Autometer Street Tach I had been using for many years. As a second test I hooked up a digital multimeter and set it to tach mode. I am happy to say that not only does the Shiftworks tachs work with an MSD box but they are very accurate. It matched my Autometer tach in accuracy and responsiveness.
Installation required the complete removal of the instrument cluster. For 1968-76 Novas that means disconnecting the battery, removing the radio, disconnecting the shift indicator wire from the column (on automatic Novas), lowering the column by removing the 2 nuts holding it up, removing all the screws (8) holding the instrument cluster to the dash, disconnecting the HVAC controls (3 screws) disconnecting the wires for the headlights, wipers, seatbelt warning light, the light for the wiper switch, the speedometer cable and the main instrument cluster wiring connector. I also had to disconnect my Autometer tach. Once the cluster was out, you remove the light bulb on the clock side, remove 2 screws that hold the cover plate on, carefully move the ribbon wire harness out of the way and pull the block off plate (or clock) out he back. The tach just slides in using 2 tabs for proper alignment. Next lay the ribbon wire harness back over the tach and replace the 2 screws to hold everything together. Next, replace the light socket. Do yourself a favor and replace all the bulbs at this time. I think there were 15 altogether and let me tell you, it made a huge difference after everything was back in the car. None of my bulbs were burnt out but the new bulbs were much brighter.
Because 1968-74 Nova clusters have square openings, the face of the Shiftworks tach is square. 1975-76 Nova clusters, however, have round openings for the fuel and clock. Don't let this worry you as the Shiftworks tach looks good in the opening. You can see some of the edge but only if you look very closely.
OK, now that the tach is physically in the cluster it's time to mount and wire in the brain. Be sure to mount it close to the tach face as the harness that connects the two is not that long. I used wire ties to attach the "shotgun shell" to the main wiring harness of the car right behind where the tach will sit. Then I connected the 3 wires to the matching 3 wires of my shift light and then to where the previous tach wires were connected. With everything working I replaced the cluster into the dash. Don't forget to connect all the wiring and the speedometer cable.
How does it look? Stock. Yes, it's smaller than my Autometer tach but it is much larger than the factory in-dash tachs. The factory 1968-74 and 1975-76 tachs only has a 90-degree range for the needle to sweep. Shiftworks tachs use a 270-degree range of the needle sweep. That is 3 times the space which makes seeing the tach much easier. And now my speedometer is unobstructed by the Autometer tach. Before - After
If you are interested, visit the Shiftworks® website or email them at email@example.com.
Happy Motoring! - Scott
copyright Scott Windle- reproduced with authors permission
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