NASCAR knew Sunday morning at Daytona International Speedway, that the 206-plus mph speeds seen in Saturday night's Budweiser Shootout were unacceptable for the rest of Speedweeks.

"What we know is, we can have good races at 100 miles and hour and 200 miles and hour and everything in between," Sprint Cup director John Darby said on Sunday evening. "I think we can agree, for both the competitors and NASCAR, that 206 was probably a little bit to the extreme side, so we'll do what we can do to probably cushion that, some."

NASCAR issued a bulletin Sunday that attempts to equate the four manufacturers' ability to control their engines' water temperatures. At the same time, it continues trying to limit their ability to engage in speed-building two-car drafts.

The bulletin resulted in a steady stream of crew chiefs, engine tuners and engine builders taking advantage of NASCAR's "open-door policy" to come to its mobile office trailer in the Sprint Cup garage to visit with NASCAR vice president for competition Robin Pemberton and Sprint Cup Series director John Darby for clarifications.

Earnhardt-Childress Racing Engines president Richie Gilmore said the bulletin was a little different than what he expected to see and that many teams "didn't have their cars plumbed [the way the bulletin dictated]."

"What they're looking to do is put an external pressure-relief valve [near] the top of the water [overflow] tank," Gilmore said, explaining that the bulletin mandated set-diameter hoses to and from the tank and a pressure-relief valve supplied by NASCAR and set to 33 PSI.

In addition, the bulletin mandated a change to rule book section 20-7.3, whereby, no matter the shape of the grille, per manufacturer identity, it would have an aluminum plate behind with a rectangular opening with a 50-square-inch maximum opening for cooling.

Darby said NASCAR would have the ability to check the dimensions and the valves' pressure ratings post-race and that variations would be subject to penalties, per the rule book. Darby said the concern among the competitors was "pretty low."

Gilmore said the goal was relatively simple.

"What that's gonna do is drive the cars to where they're probably not going to be able to push as long," Gilmore said. "In two or three laps they'll have to get out [of line] and get some air, or they'll start pushing water [out the pressure-relief valve].

"They're trying to get it to where we can only run about 230 degrees of water temperature. Guys the other night were pushing for 10, 12 laps or more -- and they were probably seeing 260 degrees of water temperature. But it was staying there because guys were running a higher-pressure [radiator] system."

And Darby said that, while a restrictor plate change is still on the table, NASCAR opted to go this route, first.

"If you look at what creates speed, the plate would be fine as it is," Darby said. "If drivers never pushed each other, we'd be putting bigger plates on the cars; so that's part of what we want to watch -- how the cooling system changes and what the reaction to it is, and we may not have to change the plate. That's what we've got to watch on Wednesday."

There is no track activity at Daytona until Wednesday, and most competitors were planning on returning to their shops in North Carolina anyway.

"We all get to go home," Daytona 500 pole-winning crew chief Steve Letarte said. "I get to go to the shop Monday and Tuesday. We get to run stuff on the [engine dynamometer]. I think the first thing we'll do is we'll take all that information and feed it into our dynos. We have engines at home. We'll test our water systems and find out exactly what kind of criteria that will affect the car. We'll come down and decide.

"We're going to tiptoe into it. I think we have a lot of practice left. I think the opportunity to run, you can learn a lot with just a teammate -- especially when it comes to cooling -- the two car push. We'll apply [the rules] the best we can and come up with a very diligent plan for Wednesday, definitely not go into it blindfolded. We'll go into it with a specific plan."

NASCAR spokesman Kerry Tharp said that on Saturday, NASCAR requested teams remove an auxiliary engine-cooling hose in an attempt to minimize their ability to engage in two-car drafts in which the cars are literally constantly in contact, with the first car breaking the air-resistance and the second car taking advantage of that to push both cars more quickly around the track.

"Some teams didn't have it but some did, and we asked them to take it off to cut down on some of the cool air the engine gets," Tharp said. "It wasn't intended to reduce horsepower; it was something we tried to see if it would curtail the length of those two-car hook-ups."

However, as Shootout runner-up Jamie McMurray pointed-out, his team doesn't even run the hose in question -- as a number of other teams don't -- and he was able to push Shootout winner Kurt Busch constantly for more than 12 laps Saturday night, when ambient temperatures were near 40 degrees Fahrenheit. Conditions were ripe for the speeds that were recorded, and that was enough for Darby.

Even though race-time temperatures on both Thursday, for the Gatorade Duel 150 qualifying races and Sunday for the Daytona 500 are expected to be warmer, thereby slicking up the race track and lowering speeds, NASCAR was compelled to try something.

"It was so cool [Saturday] night, when the car would get 275 degrees [of water temperature] you could peek the nose out and my car would go back down to 230 in a straightaway," McMurray said. "And if it's 40 degrees hotter on Thursday it's not going to do that. Yeah, I think it'll be a lot different racing when you have to swap [[positions in the two-car drafts], where [Saturday] we didn't have to."

But three-time Daytona 500 winner Jeff Gordon said the art wouldn't completely go away.

"We used to run like, maybe two laps at Talladega, lap and a half at Talladega, was about as long as you could run [without overheating]," Gordon said. "These teams went to work over the off season. Look now, we're running 30, 40 laps in a row. We figured out how to do it without even having to swap [positions] over.

"So I think cutting that restriction down would certainly stop us from being able to push as long, but it's not going to stop us from pushing. It doesn't matter if you can push a guy for a half a lap -- if it makes you go faster, it makes you go faster, you're going to do it.

"That just means you're going to have to figure out how to get some air to cool the car down, poke our nose out, back off a little bit. So as long as those bumpers line up and the airflow over the cars is the way it is, I don't think you're going to stop it."

Once NASCAR made the cooling system decision, the teams were in position to do the rest.

"The way Speedweeks is broken up, the most important day of the week, make sure everyone knows this, is the Daytona 500. The 150s have to be a way to verify some of the changes, that's what we'll do. We want to make sure next Sunday we put on a great show for a lot of fans that have traveled a long way to come see us."

"The game has changed, that's all I can say," Gordon said. "You can't take knowledge and throw it away. Once you have it, you have it. You maintain it, you apply it. No matter what changes from now to Sunday, we're still going to have that knowledge. We'll try to use it to our advantage.

You talk about the cooling; you talk about the rev limiters -- all those things. Now I got to figure out who has 9500 [RPMs]. Shoot, we can't run 9500. We got some work to do [smiling]. But, you know, the thing is there are going to be some guys that are going to try to do it for 500 miles.

"I think there's going to be some guys that fail from an engine standpoint. We've known since January coming down here that we can't do that for 500 miles. That's if we run high temperatures. What we're doing in testing is we push till we got to like 260, 270 on the water temp, then we would swap and let it cool down, then we'd swap. We did that. We didn't think we could do it for 500 miles based on what we saw on the engine.

"There are going to be guys that take the risk and try it. We're here to do whatever it takes to win the race. So we'll see kind of what happens over the next few days. We are going to take it day to day and make our plan from there."