Rev counter picku
Rev counter picku
Ive read that the 605/6 get the revs by the flywheel, but that's what changes too.
So how could i get the rev counter work again?
Greetings from germany.
Maurice
Cheers mates, now i ve build a w202 om 605 smoker with mechanical pump and He351w and swapped the 722.6 to 716.657. The speedo works fantastic, but my rev counter does nothing.
Ive read that the 605/6 get the revs by the flywheel, but that's what changes too.
So how could i get the rev counter work again?
Greetings from germany.
Maurice
Your manual flywheel obviously doesn't have the tags. Perhaps get a flywheel from a manual w202/605? Or weld on the 5 tags..
?
Installed:
OM606/722.6, big IC, W220 brakes.
Planned:
DIY manifold, compound, 722.6 controller, built IP.
[i]Less rust.. [/i]
w202/605 tack picks up 5 tags from the back side (engine side) of the flywheel. Sensor is right hand side of the flywheel housing, half way down.
Your manual flywheel obviously doesn't have the tags. Perhaps get a flywheel from a manual w202/605? Or weld on the 5 tags..
?
Installed:
OM606/722.6, big IC, W220 brakes.
Planned:
DIY manifold, compound, 722.6 controller, built IP.
[i]Less rust.. [/i]
1. Install a trigger wheel on the front pulley, just like on those gasser megasquirt conversions.
2. Use the sensor that reads the ring gear teeth, feed the signal to a microcontroller which would convert the frequency so that rpm is correct. Ring gear has 144 teeth. You would have to drill a new hole for the sensor.
3. Use a sensor mounted on the front pulley, reading the single tab there. Again would need a microcontroller to convert the frequency of the pulses.
4. Remove flywheel and weld tabs.
I'm curious if the AC works with no rpm signal ??
I can think of a couple of solutions:
1. Install a trigger wheel on the front pulley, just like on those gasser megasquirt conversions.
2. Use the sensor that reads the ring gear teeth, feed the signal to a microcontroller which would convert the frequency so that rpm is correct. Ring gear has 144 teeth. You would have to drill a new hole for the sensor.
3. Use a sensor mounted on the front pulley, reading the single tab there. Again would need a microcontroller to convert the frequency of the pulses.
4. Remove flywheel and weld tabs.
I'm curious if the AC works with no rpm signal ??
and, the ECU also needs RPM signal, because of reasons.. and there is no other place to pick it up?
Evgeniy1987
06-28-2016, 01:39 AM #6I would say ECU, as 144 teeth would be nonsense for the tach only and, the ECU also needs RPM signal, because of reasons.. and there is no other place to pick it up?
Stock C250 uses 5 tabs welded to the flywheel, right in front of the ring gear
![[Image: 13536106_1100213596717114_1937934420_n_zpspvmmikxo.jpg]](http://i1353.photobucket.com/albums/q663/Petar/13536106_1100213596717114_1937934420_n_zpspvmmikxo.jpg)
And the signal is read by the ECU... Which sends the speed signal via CAN to the instrument cluster... I'm not 100% sure it works that way but i think it is correct.
The 144 teeth are actually teeth on the starter ring gear, that's why there's a lot of them
Stock C250 uses 5 tabs welded to the flywheel, right in front of the ring gear
And the signal is read by the ECU... Which sends the speed signal via CAN to the instrument cluster... I'm not 100% sure it works that way but i think it is correct.
Ive Seen some aftermarket counter on ebay, Most of them should work with plug w on the Dynamo. They have a Poti inside to find the right point of Signal from the Dynamo. Someone USE such a counter and could say what Poti is inside?
From my Std beginning Ive Got 2 Potis for the resistor mod. 1 with 20 k 1 with 5 k. Would be nice if one of the electric junks knows something ( i hate wires
)Bruno, sorry man, till now i had no time to get an own topic. A year ago i liked to Start a 602 building on my old 124 but skipd it of rust
The 202 is in very good condition.
But i would answear at all questions u have
Maurice
Shit, dont want to stick the gearbox off for such a Little mistake.
Ive Seen some aftermarket counter on ebay, Most of them should work with plug w on the Dynamo. They have a Poti inside to find the right point of Signal from the Dynamo. Someone USE such a counter and could say what Poti is inside?
From my Std beginning Ive Got 2 Potis for the resistor mod. 1 with 20 k 1 with 5 k. Would be nice if one of the electric junks knows something ( i hate wires )
Bruno, sorry man, till now i had no time to get an own topic. A year ago i liked to Start a 602 building on my old 124 but skipd it of rust
The 202 is in very good condition.
But i would answear at all questions u have
Maurice
(06-28-2016, 07:15 AM)STDGer Shit, dont want to stick the gearbox off for such a Little mistake.I got the tach working on my w124 by fitting an alternator with a W wire. This is connected to a Dakota digital box and the output is wired directly to the back of the tacho via the old loom.
Ive Seen some aftermarket counter on ebay, Most of them should work with plug w on the Dynamo. They have a Poti inside to find the right point of Signal from the Dynamo. Someone USE such a counter and could say what Poti is inside?
From my Std beginning Ive Got 2 Potis for the resistor mod. 1 with 20 k 1 with 5 k. Would be nice if one of the electric junks knows something ( i hate wires
Bruno, sorry man, till now i had no time to get an own topic. A year ago i liked to Start a 602 building on my old 124 but skipd it of rust
The 202 is in very good condition.
But i would answear at all questions u have
Maurice
The car was originally Petrol K-Jetronic.
The tach works perfectly and is adjustable.
I had a tooth counter but could not get it to work. I believe you can retro fit a ‘w’ output to any alternator, or just get another from a breakers that does.
W124 om606 HX40 finished and it's a beauty 450bhp/456ft-lbs
maxypriest
07-04-2016, 04:46 AM #10(06-28-2016, 07:15 AM)STDGer Shit, dont want to stick the gearbox off for such a Little mistake.I got the tach working on my w124 by fitting an alternator with a W wire. This is connected to a Dakota digital box and the output is wired directly to the back of the tacho via the old loom.
Ive Seen some aftermarket counter on ebay, Most of them should work with plug w on the Dynamo. They have a Poti inside to find the right point of Signal from the Dynamo. Someone USE such a counter and could say what Poti is inside?
From my Std beginning Ive Got 2 Potis for the resistor mod. 1 with 20 k 1 with 5 k. Would be nice if one of the electric junks knows something ( i hate wires
Bruno, sorry man, till now i had no time to get an own topic. A year ago i liked to Start a 602 building on my old 124 but skipd it of rust
The 202 is in very good condition.
But i would answear at all questions u have
Maurice
The car was originally Petrol K-Jetronic.
The tach works perfectly and is adjustable.
I had a tooth counter but could not get it to work. I believe you can retro fit a ‘w’ output to any alternator, or just get another from a breakers that does.
W124 om606 HX40 finished and it's a beauty 450bhp/456ft-lbs
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