Tachometer rebuild Options

[totle]

Hi,

Anyone that have a DIY description of how to rebuild a 7k Tach to a 10k Tach ?
and from 4 cyl to 6.

I would think that there is someone who has done this.
Any potmeter adjustments, og parts that needs to be replaced ?

I know that NHS does this, but would be nice to do it and just buy a new faceplate

[914forme]

You all make me (IMG:style_emoticons/default/av-943.gif) I tried to stay out of this topic I got hooked. (IMG:style_emoticons/default/headbang.gif)

Tim's solution works great. Would love to change all internals to modern servos. I mean all of them.

This allows for all the odd modifications people like to do to these cars.

10K Tach is worthless if the engine can not spin above 8 K. Just place your red line at 8K, I could sell you a face for less than the $100 price mark and it would work. I get doing a 10K tach for a GT car, but still, it is an 8K tach, use the stock tach and modify the face, and internals done.

As Larmo and Bob have stated the VDO tach really is a placebo it can be way off from the factory. Spokes simple solution works to solve the tach bounce.

One issue with Tim's method is the tach can go a full 360 degrees not bad if you have a stock tach in place. Bad if your using a 930 Tach or adding a gauge in the bottom of the tack for fuel, voltage, Amperage, etc.....

So you want to make a 10K Tach that is built from less than $100 - here is your answer.

Layout the new gauge face onto the stock tach, I would suggest using software for this that allows to layout a face based off degree.

Figure out how you want to do the face.

I have messed with all the following
Silkscreening - original method, and time consuming, but can be made to look correct or look like a (IMG:style_emoticons/default/barf.gif)

Transfer method - great for making one off stuff, very time consuming and can be extremely frustrating

vinyl masking - like silk screen - looks great, I can tell you removing every mark and letter can take for ever, then you airbrush the face, and peel off the mask, (IMG:style_emoticons/default/wacko.gif)

Laser etching, if you want aluminum letters or use a different plastic face, fast, efficient, you really can not paint two layers and get this to work right. You would think this is the cat meow, but in the end I killed this cat.

Right now I am messing with printer technologies using multiple substrates and printers. Still trying to find the right mixture and combination. I have two promising methods with this system. One from Bob on here has been extremely helpful with his method.

Sunpro Tach movement or stock. Figure out the proper resistor or add a variable resistor to find the magic resistor to get your full sweep. Get a low frequency pulse generator to make sure your Tach matches with your calculated degrees and the RPM you envisioned. Adjust until you get it right. Due to age the stock tach might not be accurate through the entire sweep. If it was me I would make damn sure the Red line reads accurate or even above / below the red line. Example your read line is 8K I would want it to be really 7800 RPM not the real 8000 RPM. So the real number is above the actual value. Or the Actual value is below the printed number. All perspective B.S. Way safer than blowing up an engine. I also install rev limiters in my cars
But I will say once all that is done as a DIY you could pull this off for less than $99, if you do not count your time.

Enjoy . (IMG:style_emoticons/default/screwy.gif)

I do know what I would charge to produce one, and well it ain't cheap, and I am only doing the ones I have in queue right now. I am back logged like crazy (IMG:style_emoticons/default/wacko.gif)