NASCAR wrestles with mix

Cars have exceeded 206 mph during the past week at the Daytona International Speedway, marking the highest speeds since Bill Elliott reached 210.364 mph in qualifying for the 1987 Daytona 500.

"Our biggest concern, obviously, is speed," NASCAR president Mike Helton told Reuters. "The speed has to be reasonable enough to keep the car where we want to keep it.

"I think that's what we're chasing."

In May 1987, Bobby Allison's car launched into the fencing at Talladega, Alabama, resulting in a carburetor restrictor rule that limited airflow to the engine.

Speeds were mostly kept under control for the last 20 years as NASCAR worked to alter rules to make sure cars could not top 200 mph.

But the Daytona International Speedway has been repaved for the first time since 1978 and drivers are now using a two-car tandem drafting technique - turning two fast race cars into one speeding bullet.

"I've always said the most important thing is we keep the race cars on the racetrack," Ryan Newman, winner of the 2008 Daytona 500, said.

"So whatever we've worked on with our liftoff speed, if the car is going backwards, sideways, whatever else to keep the cars down, that's what NASCAR needs to focus on for making the race safe."

Last weekend NASCAR issued a number of rules changes to slow the cars.

One was a tighter carburetor restricter and the other reduced the size of the front grills. Changing the size of the grills makes the engines run hotter, forcing drivers to break up the two-car draft sooner - resulting in slower speeds.

"Hats off to NASCAR because they had to do something," Jeff Buon, winner of one of Thursday's Twin 150 mile qualifying races said.

"We can't run 205, 204 miles an hour. I told Mike Helton this morning I wouldn't want to be in his shoes making his decisions."