Jimmie Johnson and crew chief Chad Knaus swept both New Hampshire races in 2003. Credit: Autostock

Tech Q&A: Chad Knaus

Jimmie Johnson did last year what no one else has been able to do at New Hampshire International Speedway: sweep.

Johnson won both races at NHIS in 2003, the first time that's been accomplished at the 1.058-mile track since two races were run there back in 1997.

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Certainly, Johnson deserves much of the credit for piloting his No. 48 Chevrolet around the tight oval. But crew chief Chad Knaus deserves some accolades, too, for setting the car up for such a difficult track.

New Hampshire has long straightaways and flat turns, so getting a car to handle around there is a daunting task. But Johnson and Knaus were able to do that last year, as NASCAR.COM's Lee Montgomery talked with Knaus about attacking the Loudon, N.H. track.

Q: I want to talk about tires, tire pressure and how you guys handle them. For New Hampshire, are the left-side pressure significantly lower than the lefts for other places?

Chad Knaus: Yeah, it's definitely lower at Loudon than what it is a place like Chicagoland or Kansas or anything like that. It's not near as low as what we'll get at, say, Martinsville. Or maybe even Richmond we might get lower than what we do at Loudon.

Credit: Autostock

It's a lot lower, and there's a lot of different reasons for that. One of the reasons is the simple fact that less air pressure on the left-hand side lets the car turn in the center of the corner a little bit better a little bit longer.

But on the other aspect of it, it gives you the option to come in for a pit stop and take two tires. The left-side air pressure doesn't build up too much to where it overrides the right side.

Q: Let's say your car is a little loose, and you wanted to adjust that with tire pressure, how would you do that?

Knaus: It depends on what's going on, but typically, if you're loose on throttle off the corner, you'll go up on the left-rear air pressure a little bit. And that's just like putting a little left-rear spring in the car.

Q: And that's just on the left side? You wouldn't do that on the right side?

Knaus: If you wanted to try to tighten up the car with the rear air pressure, what you would do is take some out of the right-rear.

Q: Is that something that's kind of standard up and down the garage?

Knaus: No. There's no standard. Everything is car dependent, spring and shock dependent. People have different theories of what works and how. I'd say that's a basic rule-of-thumb.

Credit: Autostock

Q: Now, Loudon being a flat track is a different animal than most places we go to. You're hauling butt down the straightaway. Is the whole key getting the car to turn at the start of the corner?

Knaus: Typically what happens is the car gets loose on corner entry, and then it gets tight in the center, and then some people end up tight off the corner and some people end up loose off the corner. It just depends on the setup.

But usually, drivers will complain about being what they say "free" into the corner and then tight in the center, trying to get the car to turn in the middle. It's definitely a balancing act.

Q: Explain the concept of "rolling through the corner." Is that just simply off the throttle with the car turning?

Knaus: Off throttle, off brake, the car making its own way around the corner and carrying as much speed through there as you possibly can. The more you have to use the brake, obviously, the more you're going to slow down. The more you can let the car roll freely, the less abusive you are on the tires, the faster you're going to be for a longer period of time.

Q: Is that more important than corner entry? Or is that just something else you have to think about?

Knaus: You have to start on the entry. If you can't get in the corner, you're not going to get through the center, and you're not going to get off. We always focus on getting into the corner first, and then we move on.