DAYTONA BEACH, Feb 19 — Nascar continues its quest to strike the right balance between speed and safety after cars preparing for tomorrow's Daytona 500 reached speeds not seen in 24 years.

Cars have exceeded 206 mph (331 kph) 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 yesterday. "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 carburettor 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, told reporters.

"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 carburettor restrictor 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 Burton, winner of one of Thursday's Twin 150 mile qualifying races told reporters.

"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." — Reuters

SAO PAULO, Feb 19 — Pele says Brazil risks embarrassment if preparations to host the 2014 World Cup do not get up to speed soon.

Brazil's greatest footballer said he was most concerned about delays in building or improving stadiums and modernising the country's "frightening" airport system.

"You know of the fight we had to get the (2016) Olympics and the World Cup, travelling around the world seeking votes and now a moment has come that is worrying everyone," Pele told a news conference on Friday.

"Brazil is running a great risk of embarrassing us in how it runs the World Cup, principally in communications. The airports are frightening and not just for Brazilians."

Pele said he spoke with directors of world soccer's governing body Fifa and also a group linked to European body Uefa's president Michel Platini, who also expressed concern over the pace of preparations in Brazil.

Most of the works for the World Cup are behind schedule and some of the stadiums have not even begun to be built as in the case of first division club Corinthians, chosen by Sao Paulo city as its match venue.

"Brazil has the obligation to stage a good World Cup, a good administration, and sadly it's already behind and has this controversy of Sao Paulo," the 70-year-old Pele said.

"The Paulista championship is the core of Brazilian football, it's what should already be settled and it still isn't settled."

Sao Paulo will stage the tournament's opening match, according to the organising committee, but it is unclear how Corinthians will enlarge their stadium to the 60,000-capacity required by Fifa. Work is supposed to start next month.

Apart from the stadiums, infrastructure improvements are also required, especially to the inadequate airports.

In Brazil, air terminals are close to saturation point and Sports Minister Orlando Silva has said that is a major obstacle ahead of the World Cup. — Reuters