NASCAR has announced changes to the technical specification of cars for the restrictor-plate race at Talladega Superspeedway in October, which may lesson the domination of two-car drafting seen on the track.

The restrictor plate that teams have to use to lessen engine horsepower and reduce topline speeds on safety grounds to under 200mph are being enlarged by 1/64th of an inch to 57/64ths of an inch in diameter, which will slightly increase the engine's power by around 10 horsepower (resulting in an extra 2-3mph speed) but leave it slightly more prone to heating issues.

In addition, the pressure relief valve on the cars' cooling systems will be changed so that they come into play at a slightly lower water temperature steam pressure. That means the cars will now need to take more frequent breaks when running in two-car drafts.

Races at Talladega and Daytona earlier this season showed that cars with the old settings could run in a two-car tandem for a relatively extended period. The new settings should mean that the car doing the pushing will start to overheat quicker than before and will need to break the draft or switch to the front position more often.

"The new rule on the pressure release valves at superspeedways is just going to limit the time that you can push nose-to-tail," said Martin Truex Jr.'s crew chief Chad Johnston. "It's going to make you switch more often, which could be a good thing or it could be a bad thing. The chances of something going wrong on a swap are going to go up obviously, but hopefully it will eliminate or lessen the two-by-two racing."

"After the last few superspeedway races, we've heard many drivers express their desire to open up the size of the restrictor plate some and we thought the time was right to do that," said Robin Pemberton, NASCAR's vice president for competition.

Not everyone agrees that the changes will have the desired effect, and if speeds climb higher than anticipated than NASCAR may change the specifications at short notice during the race weekend on safety grounds as happened ahead of this year's Daytona 500, when speeds of over 200mph rang serious alarm bells for series organisers.

Few expect the changes to result in a return to the old style of two- and three-wide long-line drafts that has historically been the restrictor-plate style of racing until this year, and hooking up with a 'dance partner' for the race is still likely to be all-important.

Dale Earnhardt Jr. for one was critical of the new two-car drafting that arose in this year's restrictor-plate races. "I don't like this kind of racing," he said unequivocally after the second outing at Daytona in July. "What kind of move can you make in racing like this? There ain't no move you can make. You just hold it on the mat and try not to wreck into each other."

However, the changes certainly suited Hendrick Motorsports, which dominated Talladega and saw Jimmie Johnson claim his sole victory of the season so far.