***CAUTION ** CAUTION ***
MSD 7531 TRACTION CONTROL IGNITION BOX
THIS IS AN EXCELLENT IGNITION!!! WORKS PERFECT!!
THE PROBLEM IS INEXPERIENCE IN PROGRAMMING THESE BOXES! THIS IGNITION WILL DO SO MUCH AND I HAVE HEARD THE INSTRUCTIONS ARE A LITTLE VAGUE FOR "ROOKIES". IF YOU ARE HAVING A "MISFIRE" PROBLEM ABOUT 100' OUT ITS THE WAY YOU HAVE THE BOX WIRED!! YOU MUST USE CAUTION WIRING THE LAUNCH REV LIMIT!!
IF YOU WIRE YOUR TRANS BRAKE TO THE WRONG WIRE FOR THE LAUNCH REV LIMIT, YOU WILL ALSO ACTIVE THE "SAFETY OVER REV FEATURE"!! RICK WROTE A NICE TECH ARTICLE ON WHAT GOES WRONG!... THANKS RICK!!
We have the same box. Our transbrake was wired to the launch rev limit wire (Dark Blue). Now when you let go of the transbrake it starts the Timed Safety Rev Limit. I think this is more for Pro cars like Pro Stock so that they cannot keep reving past the finish line. The Rev Limit is user set from 1 to 12 seconds and 1,000 to 12,500 RPM. If the RPM value that is set for the Launch Rev Limit (transbrake in our case) it will start the Timed Safety Rev Limit. The MSD box will then pull timing out at the set time and work its way down to the RPM set in thhe Timed Safety Rev Limit values. There is no way to turn this feature off when using the Launch Rev Limit wire!! So what we did at first was max the time out to 12 seconds. It worked great for the rest of the weekend. Now if you have a slow 1/4 car (slower then 12.0) I think you're screwed, but who would be using a transbrake on such a slow car anyways. One other thing you can do is wire your transbrake to the Burnout Rev Limiter (light blue wire) and use that as your two step. That does not set any timers or safety rev limits.
BIG RICK'S TURBO FIRBIRD!
