I am trying to wire the 2 step launch control on my MSD box. Its a 6212 that needs to see 12 volts on the wire to engage the 2 step rev limit. I am trying to get the signal from the clutch switch but it only has power going to it when the ignition is on start and not on run. How have you guys wired yours up. I don't want to have to hold a button and then let it go when the lights turn green.

Originally posted by Crab1092
I don't want to have to hold a button and then let it go when the lights turn green.

That's how you wire a two-step.

..and I thought the MSD wanted a ground signal for the two step, not 12v.

*edit*

per the instructions:

Blue
Two Step feature. To activate low rpm limit, connect this wire to ground.

I have my two-step connected to the e-brake wire. I had to use a relay to get it to work right. If you want i can post a diagram later today. Mine works just fine, and i can hold the e-brake and use it kind of as a line lock at the track.

Originally posted by Slammed420A
I have my two-step connected to the e-brake wire. I had to use a relay to get it to work right. If you want i can post a diagram later today. Mine works just fine, and i can hold the e-brake and use it kind of as a line lock at the track.

Diagram it, put it in the wiki for future reference.

http://www.msdignition.com/pdf/6212_frm%2024841.pdf

page 13

I just wired mine up to a SPDT Switch and a momentary push button alone. So all you need to do it throw the swith to the RPM setting you want and then hold down the button. The reason I did this was becasue once I looked where the clutch switch was I just said forget it. It wasn't worth my time to wire up the clutch switch into the circuit for my slow ass POS that I only occasionaly take to the track. I could draw something up if you really need it.

Ok, here is how I wired my two-step.
I wanted to put it on the e-brake so i could pull the brake and use it as a form of a "line-lock"

There is only one wire connecting to the E-brake, but it is a ground
(-) wire. The two-step function requires a +12v.

Wiring as follows...
Get a 30 Amp relay

Blue Two-Step wire from MSD box-pin 30
E-Brake wire-pin 85
+12v wire(from battery)- pins 86 and 87


I just took one wire from the battery and put it to both pins 86 and 87.

This will only avtivate your two-step when the E-Brake is engaged.

if someone wants to add this to th Wiki, feel free. My connection at home is frikin slow, and it would take me forever.

Ok i finally figured it out to do exactly what i wanted. The way i have it setup i stage the car, push my clutch in, and then push a momentary contact switch. I let the switch go and until i let the clutch off my 2 step is on.

You need two relays. One needs to be a five prong and the other needs to be a 4 prong.

Take the five prong relay and connect the ground prong(prong 86) of the relay to the blue wire on the clutch switch. Connect prongs 85 and 30 to a switched 12v source ( i used the cigarette lighter power). Put a female disconnect over prong 87 so that nothing can ground it out. Now prong 87a( the center prong) will give out a 12v only when the clutch is pushed in. Connect prong 87a of the 5 prong relay to prong 30 of the four prong relay.

The following is done on the four prong relay:

Ground prong 86
Connect the outlet of the momentary switch to prong 85
Connect prong 87 to the wire on your ignition box for your 2 step
Connect a jumper wire to prongs 85 and 87.

I like this setup much better than having to let the e-brake go or just holding a switch down because it leaves less for me to think about at the starting line. It also eliminates the possibility of me cutting the 2 step off either before or after the clutch is let off.

That is a pretty nice setup as well. i may consider doing that.