Rev counter connections
-
- Donor
- Posts: 4973
- Joined: Wed Sep 14, 2005 9:24 am
- What model do you have?: 77 SP
- Location: Johannesburg
- Has thanked: 5 times
- Been thanked: 98 times
- Contact:
Rev counter connections
I have a old 2002 BMW Rev counter that I intend on fitting to my engine stand, it has 3 terminals marked + 1 - what goes where? I don't want to risk poping it so any help would be appreciated.
For what it's worth, ignorance has no limits ......
- Merlin
- ACVWSA Junkie
- Posts: 6124
- Joined: Tue Sep 20, 2005 8:46 pm
- What model do you have?: Various
- Location: Cape Town, ZA
- Has thanked: 20 times
- Been thanked: 39 times
- Contact:
Hey Rui,
On that subject, I've go an idea for a tachometer...
1. Do any of you here know someone into their electronics with a penchant for cars? It's a rather unique and complex idea, so I need someone who knows what they're doing...
2. What's the word on the revs with my new engine? Redline, power, etc.?
Obviously, afaik, the stock idiot marks on the speedo will no longer apply.
Thanks, N.
On that subject, I've go an idea for a tachometer...
1. Do any of you here know someone into their electronics with a penchant for cars? It's a rather unique and complex idea, so I need someone who knows what they're doing...
2. What's the word on the revs with my new engine? Redline, power, etc.?

Obviously, afaik, the stock idiot marks on the speedo will no longer apply.
Thanks, N.
"Understeer is when you hit the wall with the front of the car, and oversteer, the rear.
Hp is how fast you hit the wall, and Torque is how far you take the wall with you."
Hp is how fast you hit the wall, and Torque is how far you take the wall with you."
sled wrote:well obviously the UK is wrong.
-
- ACVWSA Junkie
- Posts: 10784
- Joined: Wed Mar 07, 2007 10:41 am
- What model do you have?: none
- Location: Johannesburg
- Has thanked: 91 times
- Been thanked: 44 times
can someone explain those marks?I'm still trying to figure out on the two Beetle speedo faces that I have at homeMerlin wrote:Hey Rui,
On that subject, I've go an idea for a tachometer...
1. Do any of you here know someone into their electronics with a penchant for cars? It's a rather unique and complex idea, so I need someone who knows what they're doing...
2. What's the word on the revs with my new engine? Redline, power, etc.?
Obviously, afaik, the stock idiot marks on the speedo will no longer apply.
Thanks, N.
If it's too low, you're too old 

- Merlin
- ACVWSA Junkie
- Posts: 6124
- Joined: Tue Sep 20, 2005 8:46 pm
- What model do you have?: Various
- Location: Cape Town, ZA
- Has thanked: 20 times
- Been thanked: 39 times
- Contact:
They're "idiot marks"...safe maximums for the revs you're pushing out with a stock engine.
"Understeer is when you hit the wall with the front of the car, and oversteer, the rear.
Hp is how fast you hit the wall, and Torque is how far you take the wall with you."
Hp is how fast you hit the wall, and Torque is how far you take the wall with you."
sled wrote:well obviously the UK is wrong.
-
- Donor
- Posts: 4973
- Joined: Wed Sep 14, 2005 9:24 am
- What model do you have?: 77 SP
- Location: Johannesburg
- Has thanked: 5 times
- Been thanked: 98 times
- Contact:
Nic, with the cam that is going in it will make power to about 5300 RPM will be no point in revving much higher than that, a rev limiting rotor will be a good investment max out at 5800 RPM, the motor should pull around 95 to 100 HP, but it will be very torquey due to the larger stroke, going by the previous stroker I had it will be a real stump puller, pulling away in second gear will be a breeze, remember this is a conservative setup, and very drivable, it will idle like a stock motor and have power right off idle. the idiot marks on the speedo will be passed before you have a chance to see them




For what it's worth, ignorance has no limits ......
- fig
- Bus Driver
- Posts: 12214
- Joined: Fri Jan 20, 2006 10:08 pm
- What model do you have?: Type 2
- Facebook: https://www.facebook.com/groups/258896479219/
- Location: Where life is cheap and death is free
- Has thanked: 287 times
- Been thanked: 322 times
- Contact:
- fig
- Bus Driver
- Posts: 12214
- Joined: Fri Jan 20, 2006 10:08 pm
- What model do you have?: Type 2
- Facebook: https://www.facebook.com/groups/258896479219/
- Location: Where life is cheap and death is free
- Has thanked: 287 times
- Been thanked: 322 times
- Contact:
- Merlin
- ACVWSA Junkie
- Posts: 6124
- Joined: Tue Sep 20, 2005 8:46 pm
- What model do you have?: Various
- Location: Cape Town, ZA
- Has thanked: 20 times
- Been thanked: 39 times
- Contact:
I don't have a rotor to swop, but I'm interested Fig...I presume this fits without hassles to that Pertronix, Rui?
Where can It one, locally, to swop you with Fig?
Where can It one, locally, to swop you with Fig?
Last edited by Merlin on Thu Aug 30, 2007 12:42 pm, edited 1 time in total.
"Understeer is when you hit the wall with the front of the car, and oversteer, the rear.
Hp is how fast you hit the wall, and Torque is how far you take the wall with you."
Hp is how fast you hit the wall, and Torque is how far you take the wall with you."
sled wrote:well obviously the UK is wrong.
- Merlin
- ACVWSA Junkie
- Posts: 6124
- Joined: Tue Sep 20, 2005 8:46 pm
- What model do you have?: Various
- Location: Cape Town, ZA
- Has thanked: 20 times
- Been thanked: 39 times
- Contact:
Shot. Is that a decent limit to top it off at in term of preserving reliablity and longevity? 
Will go shopping soon...
A stock 1600s topping off aarnd 4,500 right?
Thanks, N.

Will go shopping soon...
A stock 1600s topping off aarnd 4,500 right?

Thanks, N.
"Understeer is when you hit the wall with the front of the car, and oversteer, the rear.
Hp is how fast you hit the wall, and Torque is how far you take the wall with you."
Hp is how fast you hit the wall, and Torque is how far you take the wall with you."
sled wrote:well obviously the UK is wrong.
-
- Single Port
- Posts: 1272
- Joined: Wed Jan 17, 2007 8:56 pm
- What model do you have?: 67DC 66Fasty, 71West
- Location: JHB
- Has thanked: 13 times
- Been thanked: 10 times
ok, I will give it a go.... I have an old tacho, and it workks on a loop that comes from the coil, but then has 3 wires as well +ve, -ve and the light.
If its a newer type, there is a signal wire, +ve and -ve, but should be another one for light.... but maybe the body needs to be earthed. in which case it would be signal, +ve and light....
I think they are pretty hard to break....
If its a newer type, there is a signal wire, +ve and -ve, but should be another one for light.... but maybe the body needs to be earthed. in which case it would be signal, +ve and light....
I think they are pretty hard to break....
See my parts for sale here .... https://docs.google.com/document/d/12TS ... sp=sharing
-
- Fuel Injection
- Posts: 2114
- Joined: Sat Sep 30, 2006 10:25 pm
- What model do you have?: Aircooled, various
- Location: Kaapstadt
- Has thanked: 45 times
- Been thanked: 208 times
German vehicles use numbers for automotive wiring. 31 is earth,15 is switched positive (when the ignition is on) and 1 is the wire between the points and the coil. On a Bosch coil one usually finds the number 15,which is black and comes from the ignition switch.There is also the number 1 next to the other terminal. This goes to the points and condenser,and is also used as trigger for the revcounter.
Would say + is 12 volt, 1 goes to points and - to earth.
Just beware, VDO made a special revcounter that was used in the SP beetle.It was triggered differently,so that an extra wire to the rear was not neccessary. It sensed current change instead of voltage.It was connected so that the current from the ignition switch passed through the revcounter on its way to the coil terminal 15.The light was in a holder that could be removed.
Would say + is 12 volt, 1 goes to points and - to earth.
Just beware, VDO made a special revcounter that was used in the SP beetle.It was triggered differently,so that an extra wire to the rear was not neccessary. It sensed current change instead of voltage.It was connected so that the current from the ignition switch passed through the revcounter on its way to the coil terminal 15.The light was in a holder that could be removed.