October 1, 2008

Equipment: Reducing Driver Drag

To guard against losing of clubhead speed while wielding 460cc drivers, some players opt for less beefy heads. It's an aerodynamics thing

Baird's small-headed (300cc) driver is aerodynamically efficient.

Baird's small-headed (300cc) driver is aerodynamically efficient.

As the golf season winds down and NASCAR's Chase for the Cup nears its conclusion, it is hard to imagine there is anything that connects golf and cars, but there is—and it is not their fans.

It's aerodynamic drag. And if the term triggers flashbacks to a long-ago physics class, don't turn the page just yet: Because of drag, your 460cc driver may be costing you a couple of yards.

Ah, got your attention.

Large-headed drivers built with extreme front-to-back dimensions to increase moment of inertia also can increase drag and decrease clubhead speed. Player testing has shown the clubhead speed for a 300cc driver (measuring 3.7 inches from front to back) clocking in at 105 mph, while the clubhead speed for a 460cc driver that measures 4.8 inches from front to back decreases to 101 mph. The reason for the drop? Drag force with the 300cc driver measured slightly more than one pound, while the large-headed driver created close to 3 pounds of drag.

Most golf RD experts agree that is not much of a problem for those with slower swing speeds (85 miles per hour or less). The drop comes primarily at faster speeds. Here's where the car analogy comes in. Like a golf club, some of a car's energy goes to pushing air out of the way. On the EPA highway cycle, 54 percent of the energy required to move a car going 48 mph goes to aerodynamic drag. But drag increases dramatically as a car moves faster, so more than twice as much energy would be required to overcome drag at 70 mph. Now some cars are better at combating drag than others. In fact, an easy way to think of how a car combats drag is that it is a measure of the overall slipperiness of a car's shape. In other words, it is how much air can be pushed around the car rather than attaching to it.

While companies continue to work on reducing drag, some tour pros are opting to play smaller-than-maximum drivers. In fact, at last week's Tour Championship, 30 percent of the field used drivers measuring less than 460cc.

"Smaller can be 1 to 1.5 mph faster aerodynamically," explained Jeff Colton, Callaway's senior VP of research and development. "That equates to 2 to 3 mph more ball speed. That equates to 4 to 6 yards. You can have a 460cc driver, but you need to design it so it has the aerodynamics of a 400cc driver, and that's what we try to do."

Or, if you are Briny Baird, you simply use a 300cc driver, specifically, TaylorMade's 300 Series. "I pulled it out, and I looked down at it and I was like, you know, it looks good," said Baird. "I wasn't hitting my other driver great, so I gave it a try, and I'm hitting it as well as any driver I've played so why not?"

Why not indeed.

Spotted

Buddy Marucci had used the same T.P. Mills putter since 1969, but at last week's USGA Senior Amateur, Marucci won the title with a Scotty Cameron by Titleist Newport he bought off the rack in the pro shop at Seminole in Florida and started using in March. "I was having some problems with my eyes, and it just seemed like I could see the ball a little better with that putter," said Marucci.