No trailing, where to get tach signal?
 

So here is some background info:

Car is an 82 GS. I will not be running trailing. I have a 80 electric dizzy (no ignitors) triggering a MSD 6T box, and using 2nd gen leading coils.


So I have swapped the dizzy around and I am now getting to the wiring. I removed the trailing wiring from the dizzy as well as the electromagnetic field generator thing.

So, as the trailing signals the tach, what will I use now? The MSD box comes with a Tach output, a male spade terminal. I am not sure if I will be using that or jury rigging something for the leading? I have heard that some cars will need a tach adapter box, I am awaiting on an answer from MSD to see if I will need one or not.

http://i29.tinypic.com/20h9bsx.jpg

What is in red is what I will be snipping off for now. Come winter, car will get stripped down and rewired.

If I remove everything in the circled harness (minus the alternator wire) will all be ok?

Stu,

The tach from the MSD should work just fine. If you weren't using an MSD box, you would just connect to leading coil (-).

Im using the MSD box output in my car and it works just fine you just have to cut the little cables on the side of the box so you get an accurate reading

Cut the cables?

I didn't see any cables outside of the white wire (ignition control), pos and neg for box/coil, and signal wire.

The MSD output is just a spade connection.

http://i27.tinypic.com/2rnykqb.jpg

He might have a 6AL. Those need cables clipped for the rev limiter.

Ah, good thinking Kent :D

Thanks guys!

Ok guys, last question. I have it all wired up and ready to go. Now, the tach signal is the YG wire, do I put the spade connector on the ignitor side of the wire or the coil side of the wire?

I snipped the heads off the ignitor boots and was left with a YG and a YB. Tach signal is YG, but there is one YG at the ignitor boot, and another YG at the coil - terminal. I am pretty sure these are 2 seperate wires and not one.

I am leaning more on cutting the head off the YG wire that attaches to the - side of the trailing coil and putting a female spade on it, connecting it to the MSD. Correct?

Stu: Both YG wires are connected together in the harness, so take your pick.

I swear you live on these forums. Thanks again, remind me to send you a christmas card :)

Says the guy with 7k+ posts. :p:

Got everything done today, just waiting on the battery to charge up.

http://i29.tinypic.com/350nvyr.jpg

http://i25.tinypic.com/9sgyz5.jpg


I will be removing the coils and all wiring from that side tomorrow and begin to rewire everything.

Here are just some of the wires I have removed so far. I didn't get time to mess with the old coils and their wiring today. But she does fire up with no problem! It took 2 tries but I can't complain, she has sat for 3 weeks.


http://i32.tinypic.com/aylgld.jpg

so stu, ur not using the ignitors on the dist at all?

Nope. No pesky ignitors anywhere on my car.

http://i26.tinypic.com/2zygcqh.jpg

Red arrow is pointing where the stock pickups were. There were a pair of green and red wires, I just snipped the trailing wires and pulled them through.

http://i30.tinypic.com/2mrumva.jpg

Looking clean there.


-billy

Stu: Did you reset your timing after the install of the new dizzy? I notice that the adjustment bolt is fully advanced in the slot. You might be off a tooth if you did in fact adjust it.

Also, if you read some of Jeff20B's posts, you will see that you need to flip the red and green wires around on the SA dizzy compared to the FB dizzy to get the timing right.

FB:
green pickup to purple MSD
red pickup to green MSD

SA:
green pickup to green MSD
red pickup to purple MSD

Try that if you haven't and see what you come up with.

so how is timing adjusted with no ignition going thru the dist? do away with it altogether.

Yes just through the dizzy.

It was weird. I took off my stock dizzy and noticed it was 180* off from the marks at the bottom. Either way, I used the arrow on the rotor button to line up the 80 dizzy. Everything lined up correctly.

As for the green/red wires, I just clipped the wires that was going to the 82 dizzy and soldered on some spade connects and connected them. It fired right up.

EDIT: Also, another thing I noticed, the 80 Dizzy has more advancement/retardation movement than the later electronic dizzys. Probably a quarter inch more movement on each side. I don't have a timing light (it broke after 40 years) but I made sure it was bolted down in the same spot.

What I am saying is that you need to flip the wires around on the pickups. The timing won't be off a huge amount, but enough to mess with things. What MSD wire do you have going to what wire?

For the dizzy, it rotates at half engine speed. So, at TDC, the arrow can either be pointing towards the driver or towards the front of the car. Toss a timing light on there when you get a chance and fine tune it. I bet you are off a bit.

Wouldn't doubt that I am off. As far as what wire goes where, I will have to disassemble everything and find out. I can do that all tomorrow and have an answer.

Timing is handled by the rotation of the dizzy within the slotted adjustment. This is true for stock or his setup. As the dizzy rotates a metal pointer swings past the magnetic pickup. The mag pickup is mounted to the body of the dizzy the pointer is on the center shaft. So when you twist the dizzy body you are moving the mag pickup around. This makes the pointer come to it before or after top dead.

The wires running trough the cap and button do not effect timing. The cap and rotor are simply deciding which plug gets spark at what time.

When you convert to direct fire/waisted spark you are no longer switching between plugs getting fired, you are firing them both. Waisting the spark to the rotor that is not in position at that time.

I am going to do some more paying with triggers once I get a carb that is running correctly on the rx3 mule.


-billy

I have a video of a first start up that is uploading to youtube right now. Should be done in 30 minutes.