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Title: Sending RPM to old clocks Post by: n0ble on February 23, 2015, 03:05:46 PM All,
Just after a little help, have a VAG R32 engine and placing in a much older platform. I want to use the original clocks but the ECU does not have a speed wire... So... I have bought CANM8-RPM to take the CAN single and convert to send to the clocks, however this little unit will only do 1hz per RPM. I have measured an old ECU with a speed wire to the clocks and i need around 51hz per RPM. Anyone have any ideas as to how i can change the 1HZ coming out my CANM8-RPM to 51hz per RPM? Thanks. Title: Re: Sending RPM to old clocks Post by: Gonzo on February 26, 2015, 08:46:38 PM Why not use W-wire from alternator? Just a thought
Title: Re: Post by: n0ble on February 27, 2015, 05:27:04 AM I'm not sure that will work on golf mk2 clocks?
Title: Re: Sending RPM to old clocks Post by: Sprockets on February 28, 2015, 03:22:51 AM Hi, excuse my maths but I believe 1hz/rpm is correct and makes sense. I assume you measured approx. 50hz, which is 3000 (50x60) signals a minute. Divide by four as it's a four cylinder fired off the coil gives 750....which is very close to idle RPM, or 1Hz per rpm...
Have you actually tried it? Or am I way off! Scope shots would be helpful if you could. Options if its not are contact the manufacturer to see if they could alter the output frequency, or construct some form of PLL or uC based multiplier. -Gavin Title: Re: Sending RPM to old clocks Post by: Gonzo on March 06, 2015, 10:30:00 PM http://www.momentummotorparts.com/store/electronics.asp
How about that? Just an option. More info: http://www.customobsessions.com/phpBB/viewtopic.php?t=38747 Maybe that will give you some ideas ^ |