BigVWman
Veteran Member
- Joined
- Feb 16, 2007
- TDI
- A1 cabriolet tdi and 01 nb tdi and countless gassers!
How are things going with this idea? I would be interested in plunking down some reasonable cash to get my tach going!
Really? Do you have a link? I can't find one.tongtoy:
you can buy a 35 dollar converter on ebay and plug it in - works off of a tach signal from the car expecting a coil or an rpm sensor from a crank wheel of some kind
i'll pull the name off of the one I have in the jetta. It was an ebay purchase two years ago I guess now a days.e*clipse said:Really? Do you have a link? I can't find one.
I've found Dakota ones for $60 - $100 and a used splitter for $31, but nothing as versitile or easy to use as the one I'm developing.
For example: Say you put 33" tires on your truck that originally came with 31's. Could you calibrate your speedometer with one of these inexpensive adapters?
good info ^^ for vanagon users and may also work for toyota?Hi,
I converted my T3 syncro (vanagon) to TDI (AFN code engine).
I tried to use the tacho output of the TDI ecu (pin 2/68), but factory tachometer of the T3 (gas engine) did not work.
I took the tacho out and examined, yes there are resistors (a voltage divider) on input signal.
The chip used in the tacho is SAK215, it is a frequency to current converter. I found the data sheet of SAK215 (googled it) and it says anything between -20 to +20 V is valid as an input signal.
As the TDI output signal is a 0-12V square wave, I just directly conected it to input pin of SAK215 (bypassing all the filters and resistors in tacho), and it worked.
It is accurate as expected!
Eren B.
Well then. I cave. I have another unmolested tach and rather than modify it (perhaps unsuccessfully again) I purchased the needed bits from Rock Auto. If it ever stops raining raining here I will post back with photographic results.check out my solution for a tach driver using an inductive pickup...super simple....about the third post down starting...if you wanted to do this using a V6 tach you could weld three nuts 120' apart....
http://www.vwdiesel.net/forum/index.php?topic=3741.30
The tach is reading frequency from the W terminal, not voltage, so a resistor won't work unfortunately.Hi guys, i have a 90spec 8v gti with a mk3 ahu engine in. Ive installed the correct mk2 gtd clocks with the rev counter and reading from the W pin. It reads about 400rpm too much at idle and at a guess about 700rpm at 70. Ive seen a couple of how to's etc im wondering what is everyone elses solution to having an accurate rpm dial? Can i place a resistor on the W PIN WIRE?
Sometimes but you need a converter from dakota digital.Is it possible to run gas tachometer with w terminal?
The tach is reading frequency from the W terminal, not voltage, so a resistor won't work unfortunately.
Sounds like your tach is a bit out of calibration for your particular alternator pulley/crank pulley ratio... if I recall correctly the MK2 clocks have a couple of calibration pots on the back of the circuit board.
A little googleing might track them down.... you could also try posting over at www.vwdiesel.net... lots of folks there have done conversions and there are several detailed tach threads.
i'm not sure anyone understands the question ... could you clarify what you're trying to do ?Anyone?