Team Camaro Tech banner

1 - 15 of 15 Posts

·
Admin/Super Moderator
Joined
·
12,511 Posts
Since the menu link to our tachometer filter page is broken I have created a sticky to point to it.

http://www.camaros.net/techref/electrical/tachfilter/index.htm

Brian

Capacitor: 1 ufd, 63V, axial lead, foil wound, usualy 1/2 inch by 1/8-3/16 inch diameter - neg lead goes to case, pos lead to an insulator.

Everett
 

·
Registered
Joined
·
370 Posts
I noticed part of this goes to the coil and part goes to ground. My tach is connected directly to my coil. Do i just put this filter in front of my tach wire and solder the brown tach wire directly to the blue wire in the pictures?
 

·
Admin/Super Moderator
Joined
·
12,511 Posts
Discussion Starter #3
Chaz - Your brown Tachometer lead connects to the raw blue end on the left top in this picture.



You can either use a quick connect/disconnect pigtail arrangement as suggested in the article directions or solder it direct.

I would personally use a pigtail or other type of connector for easy maintenance. The filter can also be mounted on the dash side before the Tachometer. Its up to you as long as it is in-line someplace between the Tachometer and the coil.
 

·
Admin/Super Moderator
Joined
·
12,511 Posts
Discussion Starter #5
Yeah it is a great trick to fix an major PITA situation and it is wicked cheap and anyone can make it, because it is just that simple.

I've seen filters in a very nice project box or case being sold for under a 100 bucks. Open them up and what do you see? This type of filter hidden behind the case and considering it is about 6 bucks of materials and time to make it is insane profit.

You could really mount it behind the Tachometer and no one would ever know. You would need to make a small extension cord, straight lines for the other two connections on the Tachometer harness plug for ground and power. Run the filters ground to the new pigtail ground, and use a standard female connection and the Male spade on the output end of the filter and plug it in the existing female harness. To really dress it up maybe put it in some shrink ir cable conduit. Maybe I'll make that a winter project and see if it looks like a product I could sell LOL.
 

·
Registered
Joined
·
370 Posts
Yea I'll probably make one this weekend because my tach is bouncing. I have a Mallory Unilite setup and I think this will help it out! I will probably hide mine in the rubber wiring retainer near the cowl :) Thank you everyone!
 

·
Registered
Joined
·
158 Posts
sorry for asking such a dumb thing. Bought all this stuff years ago and never got a round to it. Think I bought a filter box from Ricks ,,,little black box says SN-76 on end of it.

Even longer ago bought tach from Ricks or Classic,,,then bought a pigtail for the back of that,,that has three wires,,,pink, black, and brown. Pink has a double quick connect, brown has an extension wire on it. Black looks like a short wire with eyelet on it (maybe a ground)

Back to the SN-76 box it has red, black, white, yellow wires, diagram says red goes to switch, black ground ,,,,

white-ecm tach signal (which is my outlet on accel dist cap marked tach????)

and yellow is noted tach signal post which is what???the pink quick connect??

need this buttoned up so can put my dash back together. thanks for any help
 

·
Admin/Super Moderator
Joined
·
12,511 Posts
Discussion Starter #9
Don the Tachometer uses Pink for 12 volts from the accessory side of the fuse panel. Black is the ground to chassis and the Brown is the Tachometer signal wire from the ignition coil in a points vehicle.

The filter - SN76 - Tach Adapter LS1 4-cly to 8-cyl manufactured by Classic Instruments. Does it look like the one in these instructions? http://www.classicinstruments.com/userfiles/files/SN76 Wiring.pdf

If it is then I assume that the yellow from the filter goes to the Brown lead back to the Tachometer, and the White on the filter box goes to your ECM - Electronic Control Module or in your case the Distributor port marked Tachometer
 

·
Registered
Joined
·
42 Posts
Thank you for this good little filter. I wonder, does it matter which capacitor lead, + or _ is soldered to the resister? Has anyone ever successfully used this low pass filter with a MSD or other ignition box? I am about to try it on my MSD 6AL, but want to have the polarization on the capacitor right.
 

·
Registered
Joined
·
42 Posts
Brian, does it matter in a DC circuit which capacitor lead: Pos. or Neg. is soldered to the resistor?
 

·
Admin/Super Moderator
Joined
·
12,511 Posts
Discussion Starter #12
It is Jim M's design and the directions are as bare-bones as the filter is but it works. If I understand your question, which end of the finished resistor gets the input and which is the output? Resistors work either end, so it does not matter which end is energized, the resistance value will be on the other end.
 

·
Registered
Joined
·
42 Posts
Thank you, I can solder it together, now. Going to use it to try to correct the readings that the MSD box is affecting.
 

·
Admin/Super Moderator
Joined
·
12,511 Posts
Discussion Starter #14
ok let us know the results
 

·
Premium Member
Joined
·
52 Posts
Does anyone happen to have a copy of the schematic that’s referenced in the first post of this thread?
 
1 - 15 of 15 Posts
Top