Dorkiphus.net - Tachometer Issues (and the fix)

Good day everyone:

First off, I would like to offer a special thanks for Jazzbass (Chris) for letting me tell you guys about this.

I don't know if any of you have experienced issues with tachs after an engine or instrument swap, so...

Several years ago when I decided to restore my '68 912, I wanted to upgrade the interior with a more modern look to match the 911 exterior. I was fortunate enough to find most of the interior out of two Dorki's '82 and '83 911's.

The items included all five gauges. Almost all of them worked great with my 912 motor except the tach. I knew this going in; a 912 motor paired with a 911 tach.

I know that there were tachs on the market that could adjust to 4, 6 and 8 cylinder applications but I could not find an in-line adapter that would do the same. I was about to take out the tach and send it off to be recalibrated when I sent an email to a fellow 912er asking if he knew of the module I was lookinig for.

He guided me to another 912er who is an electronics guru in California who he knew built a similiar module for his 912. His application however was the opposite of mine; a 911 motor paired with a custom 912 tach.

Well, after some emails and phone calls, we started a partnership. With only a few months of R&D we came up with a unit. We call it Tach-Adapt... here is my shameless plug (approved by the Dorkiphus Advisory Board).

"Tach-Adapt is a module that is used to correct the gross errors that occur when you try to use a tachometer with an engine it was not originally designed for. This device goes in-line with your tachometer signal to change and restore the proper pulse shape and rate to your tachometer so it will read correctly. It is a small non-invasive, low-cost device that can easily be removed later . It accepts input from traditional points or electronic ignition, CDI and many Engine Control Modules. It’s simple to install and avoids the hassle of the difficult, expensive alternative of tachometer removal, replacement, or permanent re-calibration by an outside service.
Note: Tach-Adapt works with 12V systems. It is NOT designed to make minor rpm corrections in a tachometer that is already correctly paired to an engine but shows small accuracy errors due to aging or other."

The installation was easy and I did not need to cut any wires. I installed it in my engine bay but it could also be placed near the tach. For my car, I found it easier near the engine.

Below are pics versions one (open) and two (installed).

Your input has always been valuable to me. :)

Thanks,

Jace