• Trial and error testing of a drag race car is great for weekend warriors, but nothing beats good engineering and solid tuning for quick lap times. The fact that most professional car builders employ at least one engineer schooled in mechanical dynamics should be testimony to the amount of research needed to run with the big dogs.
  
  

Percentage of Rise

• The relationship of your car's center of gravity to the suspension and contact patch is critical for good 60-foot times. Find this relationship by calculating the "percentage of rise (PR)."
  
  To calculate your car's percentage of rise, you must know the exact height and location of its center of gravity (CG). Next, you must draw a line from the tire's Contact Patch (CP) through the suspension's instant center (IC). This will be the chassis mount point on a ladder bar suspension, or the control arm angle intersection on a 4-link.
  
  The CP-through-IC line should intersect a vertical line drawn from the CG at some point below the CG itself. The closer that intersection is to the CG, the harder your suspension will "hit" on the launch.
  
  

Shock Mounting

• Seriously consider running your shock absorbers upside down, so that the shock-body end attaches to the chassis. Hanging the shocks in this way will reduce unsprung weight. This reduces the chance of wheel-hop without having to resort to stiffer shock settings that can reduce traction as much as enhance it. It may not seem like much, but those shock bodies weigh about 5 lbs apiece; that is a 10 to 20 percent reduction in unsprung weight.
  
  

Sequential Boost Controllers

• These are fantastically helpful devices in classes where allowed. A sequential boost controller allows you to run lower boost at launch to prevent wheel spin. It can automatically increase boost with speed or by gear change. These automatically variable controllers are pricey, but they're the only way to go for those running huge turbo boost in bracket and tire-limited racing classes.
  
  

Aerodynamic Tuning

• Downforce and aerodynamic tuning are not just for road racers. Drag cars see much higher speeds than most road racers ever will, which makes aero a serious priority for top-echelon drivers. Racers must engineer in downforce from the start to allow for things like side skirts, full belly-pans and diffusers.
  
  Although it might be tempting simply to install a huge wing or spoiler, avoid this at all costs whenever ground-effect downforce is an option (and it always is). Aside from producing top-speed-sucking drag, wings can move the dynamic center of force on your car backward at high speed. This weight shift would not be a problem if application of the brakes didn't shift weight to the front, leading to a snap-oversteer condition and loss of control at the traps.