Msd

[L78 Nova]

If you add a diode in the latch circuit it will drop the two step out when the clutch releases,


I'll try to attach a wiring diagram.
Gary

[L78 Nova]

This uses an MSD relay and a second bosch style relay to ground the brake light circuit. This lights the "brake" light on the dash when the linelock is activated.


When holding the shifter button for the burnout as soon as the clutch is released it drops out the two step so it goes to the high limit.


With clutch depressed the shifter button will latch the circuit so you can let the shifter switch go before launching.
Gary

[older racer]

hi, ok, a switch is in so can switch between high and low side, thanks .

[vetteboy]

I hooked my two step to a clutch pedal switch. I put a brake switch on the clutch pedal (copied the brake pedal side). Then I ran the red wire from the MSD to the clutch switch and then to the line lock( not the 12V side). So when the clutch pedal is press down and the line lock button is pressed it put 12v power to the MSD and switches it to low RPM side and when either one is released it switches back to the high RPM side. This allows you to do a burnout and launch the car without flipping any switches.
Brett

[Bobby Fazio]

If you use a 3 step or even just a 2-step you need a toggle switch in line on the output of the relay that you turn on AFTER burnout. The line lock still works in the burnout and with that switch turned on now the line lock and rev limiter work with the foot pedal switch but only after activated by the line lock button. I use the same method in both my stick and auto cars. I have a youtube in car video also. As far as the 3 step MSD 7al 3 box goes, launch and burnout have their own rev limiters but LAUNCH always takes precedence over burnout if both are active at the same time, which they always are in my car on the launch because linelock controls burnout for me and foot pedal controls launch. If you don't want or need a burnout limiter just pull the chip out.

[vetteboy]

With the 2-step I don’t use a toggle switch and don’t see the need for one. If I knew how to draw a wire diagram to show you how I did it, I think it would help. My sketch here sucks but I hope you get the point. Both switches have to be activated to complete the circuit(clutch pedal down and line lock pressed) and if either one is released it brakes the circuit and switches back to the high side. In the past we used a toggle switch but was forgotten about to many times. We also run cameras in our cars and that’s how we figured out that we weren’t flipping the switch. I’m no electrical engineer so maybe my way is a little sketchy but it has worked flawlessly for 3 years.
Brett

[voltdr]

It's called series wiring the 2 switches. Both switches must be activated to apply voltage to the 2-step. It will work them same way with using the brake light switch and line-lock for automatic cars.
Dan

[Ed Carpenter]

I use a 3 step burnout, starting line, high side. I rev up to about 7500 in the water and let the clutch out.