Traction Through Timing

By Todd Ryden
Photos courtesy of Michael Ray, MSD, Dedenbear, and NOS


MSD's latest Programmable Ignition, the PN7531, has been banned by the NHRA. In January DRO's Agent 1320 mentioned the NHRA's ruling, with their reasons of cost and the close competitiveness of the classes. DRO got a couple of reader letters asking about this specific product and decided to address the larger subject of affecting traction through timing as well.

The 7531 has a programmable slew rev limit. This is a feature that lets a racer program an rpm ramp over time. For example, if you launch at 4,000 rpm and shift at 8600, you can ramp the rpm over time from 4,000 to 8,600 rpm. This function simply allows you to program how rapidly your engine can gain rpm on the launch and after a gear shift.

The important thing to note here is that none of this occurs automatically. It has to be programmed by the user, which comes down to knowing how your car reacts and being able to read track conditions, just like a good tuner knows how to set the clutch or 4-link. Stay tuned to DRO for more info on what other decisions are made regarding this new ignition.

Now, here are some other products and timing information for your consideration. -Editor

2002 NMCA EZ Street Champ, Bob Curran, uses MSD's Programmable Ignition Control so he can use a separate ignition curve to get his '96 Corvette out of the hole.
Once the car is rolling and Bob shifts gears, the ignition automatically switches to a "run" timing curve. (Photo by Michael Ray)


There is a time and place to enjoy ripping off a big smoky burnout and pretending you're John Force. Off the line during eliminations is not the place.

The last thing you want to do after lighting the ambers is dump the clutch and watch the tach rocket into the red as the shift light screams and you feel the rear of the car waft around turning rubber into smoke. Adding insult to injury, you get to watch the win light click on in the other lane.

There is, of course, a good side to this - your engine is making killer power! Now to harness that power to the tarmac.


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