MSD 2-Step Install - Need help with wiring
 

I picked up a new unit and I need some help wiring it up. I would like to tie it into the brake system. So when the brake pedal is pressed, the 2-step is enabled/activated. Would I use the Blue/Ground wire or the Blue&White/12v wire? Also what/where is the brake wire located that I would tie either one of the 2-step wires into?

Looks like I would need to use the Blue&White 12v wire and tie into the brake switch right above the pedal. Does that sound correct?

You could do it that way, but remember that anytime the brake pedal would be pressed the 2-step is active. Install a small toggle or rocker switch in between to prevent any unnecessary activation.

That is a good point and I will do that. Since the car is now basically a dedicated drag car it is mostly not a big deal, but still worth doing.

That's what I did I ran it to a toggle then to the brake wire under the dash. I can't remember if it is a neg or a pos trigger wire off the brake. I just used a wire tester to figure it out. I can look tomorrow if you haven't figured it out by then.

Yes it is a good idea to run a on/off switch if your going to hook it up to the brake switch. And have it where you can reach it.What was happening to me at the end of a run (1/4 mile) and I would get on the brakes the car would backfire and scare the living crap out of me!:lol:

I did the same trick, and like it better than my transbrake. :thumbs: I use a handheld pushbutton and the brake pedal, so both are required. At the brake I only found +12v. My Harlan 2step requires a ground to trigger, so I used a relay to flip the signal. I chip it right before my car pushes thru the brakes, for a perfect launch.

I tried the MSD unit on my old car and didn't like it compared to the Synergy Motorsports unit. The synergy unit you didn't have to tune it between the shifts because it would reset after each time used.

What exactly do you mean by that.?

With the MSD unit it will reactivate every time you hit the rpm it's set too. The Synergy unit activates off a trigger and once you let go of the trigger it won't reactivate till you rearm it again. So basically what I'm trying to say is that with the MSD unit your 2 step is going to kick in each time you hit the set rpm so you will have to tune the car around it.

Sounds like it's not wired right? They all need a trigger. :smash:

I think because you wired it to constant power or off your constant power off your brake. That's why you put a toggle switch in line with your brake. So it would work as such msd triggers when your brakes are applied once let go 2 step is off, the problem is when you go to slow down it is activated again at the set rpm which is not good. So with the switch in line you just click it off while normal driving or before you brake again at the end of the run.

That makes complete sense.

I know they all need a trigger but from what I've read about the MSD unit is that it reactivates at the set rpm.

With the Synergy unit even when you drive slow it doesn't reactivate. So does the MSD unit reactive when the car ***** and hits the set rpm again?

I use the MSD in my turbo truck. You have to drop below the setpoint in order to reuse the 2-step, once the original signal is dropped.If I'm on the line holding the 2-step/t-brake and then let off the switch the 2-step can't be activated again until I drop below my 3800rpm activation setting.

freakin racecar....

One of the nice things about the Synergy unit is that you can have them build it with longer wiring so you can mount the piece and dial it in, in the car. I personally don't like how the MSD unit plugs into the coil packs and looks like a cluster. The Synergy 2 step you soldier directly into the pcm wires and hides all the wiring.

I know this is an old post, but I am trying to hook up the MSD 2 step to my 2002 Z06, i want to use the clutch switch but there are 2 wires coming out of it, there is a purple and a yellow, which one are you guys using for the 12 volt power source? I tried both with a test light and neither has power. I want to be able to hook this up to the clutch lever switch so i can use it to launch for drag racing.

If I remember right, I could not get 12v from the bottom switch but could get 12v from the top switch that cancels cruise. To make the bottom work, I had to clip the purple/yellow wires and jump them together. Then run 12v to the switch that will activate with the pedal down. The result also allows the car to start in gear, so you have to be careful with that.