ESPN's Tim Brewer answers your questions

We know NASCAR fans have a lot of questions from watching Sprint Cup races, so we went to one of our experts for some answers.

ESPN analyst and former championship crew chief Tim Brewer has many years of experience from working on NASCAR teams and has offered to share his knowledge and connections.

ESPN.com's NASCAR Icons gathered some of your questions earlier this week and Brewer obliged with the following answers:

In light of all the events at JGR this past week, I was wondering why NASCAR couldn't just give the race teams a maximum number for horsepower and then let them build the engines any way they want too. It seems like it would cut out all this mess with one team being advantaged or disadvantaged.
Bryan Madden

Brewer: NASCAR does everything they can to give the teams the bore/stroke configuration to come up with a maximum amount of cubic inches. After that they have restrictions as far as carburetor flow, and the tapered plate was implemented to make them more equal.

Now, naturally the teams work really hard with camshafts, rocker arms, valve timing and the header configuration to try to gain more horsepower. And after awhile they achieved that and that's when you have one manufacturer that's more superior and NASCAR has to go back and look at them. That's the reason they dyno the cars periodically to make sure that nobody has a really distinct advantage over another competitor.

During a race, one camera looks through the windshield and it shows the back of the hood vibrating. As this is where the carb air inlet is, doesn't that affect airflow into the carb?
Grand Prairie, Texas

Brewer: In the first place, he's very observant. And he's correct, yes it disrupts the flow of air that comes across the car. You want that transition from the hood into the cowl area as smooth as possible because all the air and the pressure you can actually put in that area you're actually feeding the carburetor a higher volume of air. And yes, it's going to make more horsepower. But it does affect the thing when it's bent and crew chiefs work in strengthening the back of the hood to make sure there's no turbulence there whatsoever.

Why do we see more glowing of the brakes with the new car, and does that hurt the performance of the car?
John Reising,
Elyria, Ohio

Brewer: Yes, they are glowing more and it hurts the performance of it. The reason they use more brakes is the car doesn't have adequate downforce, so they have to simply slow the car down to make it turn through the center of the corner.

But it hurts the performance of the car because when you see those rotors glowing red it's very, very instrumental in building up the air pressure in the front of the car, in the tires and changing the handling characteristics of the car.

What kind of adjustment were they making to Dale Earnhardt Jr.'s car during happy hour at Bristol? They had the hood up and were rocking the car back and forth and did this several times. Thanks!
Dan Kimmel,
Mount Carmel, Tenn.

Brewer: There again, it shows that the fans are paying attention because if the car remained on the ground, they'll see the guys put some aluminum plates under the front of the wheels. They're coated plates and they're back to back, there's two pieces of aluminum under each front wheel and it kind of relieves it. And when you see the guys holding the string from the front to the rear. When that scenario is happening, they're checking the toe on the car, aligning the toe in the front wheels.

Now the other perspective that he sees when they're rolling the car forward and back, that's when they have the car up on the scales. They have one pad that's designated for weighing the car and then they can [without jacking the car up] roll the car back to a neutral area and check frame heights and whatever and roll the car back forward after they've made the adjustment to re-weigh the car. They're checking for frame height and weight when they're doing that on the scales.

On the ground they're checking the toe and up in the air the scales set about 3½, 4 inches off the ground and the guys have got it worked out to a science to the less movement they can make during that transition the better off. So I've used that method for several years.

I have always wondered: How do the gas men know when the gas can is empty during a pit stop, so they can grab the second can in time to not hold up there team in the pits to get the most gas and fastest stop?
Keith Medeiros Jr.,
Mooresville, N.C.

Brewer: Between the fuel probe that he puts in the fuel receiver and the gas can itself, we use clear hose. There's about 4 inches of clear hose in there and we use about a 1-inch gap to use as a window so to speak. As soon as that gas man sees that bubble or air pocket go through there he disconnects. He has the weight of the can also, but he's looking in that window to see that air come through there and then he knows that can is pretty much empty, and that's when he'll release it and reach for the other can. But that's a good question.

If you'll notice, the gas man and the catch man are sitting there looking at that probe. [And it's a piece of clear hose that's 2¼ inches in diameter but it's like four inches long. You put two hose clamps on the can and you put two on the probe.] But they're sitting there -- I mean, anxiously awaiting -- to see that air bubble right there, and then they know that can is empty and they make that transition to the second can.