Does this sound familiar? You just received your brand new drag race clutch system, and you can hardly wait to get it put in and fire up the engine! You have a baseline starting point for the clutch static pressure and counterweight settings. Everything should be fine to just head to the starting line of the next big event and let ‘er rip, right?
While we typically recommend starting points higher than we think you will ultimately need, that does not mean that your unique combination of gearing, engine, tire size and driving will be right on the money every time.
But, like most anything else with your race car, taking your time and having patience will pay off in more consistent performances and success with your new system.
What do we recommend?
Testing runs will be most beneficial to make sure you have the clutch adjustments correct before heading to your next event. Keep in mind that the base or static pressure will control what the car does on the launch, and the counterweight adjustments will regulate the lockup of the clutch through the gears.
Start by working with the launch and dialing in the base pressure setting. Just leave the starting line a few times and note how the clutch is feeling and what your crew members are seeing (if you have a data recorder, this is where it will be helpful!) Getting a lower RPM will give you a better indication of whether you have the static pressure right or not. ‘Soft’ or ‘lazy,’ or no wheel speed at all on launch will usually indicate the need to increase the static pressure. Continue to adjust and make hits off the line only until you are satisfied with the performance.
Once you have the launch down, it’s time to see what is happening with the gear changes. Go ahead and leave and pull a gear or two only. What is the car doing on the shift? Is it soft, or is the clutch not locking up? What does the data recorder show is happening? You may need to increase the counterweight on the fingers. Add a gram or two and retry. If it hits too hard or spins wildly on the shift, you will need to take some counterweight off the fingers. A gram or two on each finger can make a huge difference during shifting, depending on your RPM.
What are the ‘ultimate’ settings?
When you can get the car to launch with controlled wheel speed and have just enough counterweight for the clutch to hold in high gear on the big end of the track, you are there!
Keep in mind if your clutch setup is brand new or freshly serviced, it will be a little soft on the first hit or two, so tuck that info away as you make your fine-tuning adjustments. Then, with a bit of patience and an afternoon of testing, you will be on the way to optimizing your clutch combination and turning on those win lights!