Chad Knaus: The genius behind Jimmie Johnson

One of the unique aspects of NASCAR relative to other forms of motorsport is the relevance given to one of the key people in every team, the crew chief. Watch a Sprint Cup race on TV and you'll notice crew chiefs get as much airtime as a coach from a football team would get during a match. They are part of the story every race weekend, but their role goes well beyond what you see on the track.

Chad Knaus is by far the most recognised crew chief in NASCAR these days, following five consecutive Sprint Cup titles with Jimmie Johnson. He joined Hendrick Motorsports nearly 20 years ago, rising through the hierarchy of the organisation to become one of its leading figures. As you will read, he is constantly pushing the envelope while trying to make the most of a very restrictive set of rules, designed to prevent anyone from having the kind of domination he held with Johnson for the past half-decade.

AUTOSPORT caught with him to learn more about what takes place inside Hendrick Motorsports, his role within the squad and many of the technical intricacies of NASCAR's elite series.

Q: How would you describe your role?

Chad Knaus: The crew chief is just like a lead engineer on an IndyCar team or the pit boss in Formula 1. We're a crew chief-driven company. Crew chiefs push the development of just about everything, whether it be a cooling package or aero development, or a different upgrade package. Crew chiefs push things along with the team engineers. It's a collective group.

We work front to rear. There's always an opportunity to find a performance gain and even within the rules you can still find a little bit. Even if it's black and white, in between that black there's still white in between every letter and there's always a way to try to find some type of improvement. We work really hard to try to find whatever hole it is so we can try to manipulate the rule and get a gain.

The pair's latest success came at last weekend's All-Star race © LAT

Q: How much has the team changed since you joined?

CK: When I started at Hendrick Motorsports in 1993 I was the 75th employee at the company at that time. Now we're at 550, so an awful lot has changed. The sport has changed so much. Obviously there's the knowledge, and taking things in-house to make sure that you've got good, dependable, reliable parts from the manufacturing aspect.

We build a lot of the racecar in-house. We don't buy very much at all. We buy a lot of consumables but the hard parts, the technology and keeping it in-house has been a big deal to what it is that we do. I think it's really helped us as a company. It's helped us flourish, it's helped us keep the money in-house, so we do our own development and everything just kind of regenerates itself. We buy parts from our own company. It's pretty amazing how Hendrick Motorsports has changed over two decades but it's definitely been for the better.

Q: Hendrick has a unique layout, being two two-car teams. Why is that better than a single four-car layout, as other organisations have had?

CK: Is it the same? No. But is it better? I think it's difficult to answer. Mr Hendrick and the philosophy at Hendrick Motorsports has always been to allow the teams to work as individuals. Each crew chief, each driver, is able to go and implement whatever it is that they want. That being said, we've also learned over the course of the years that having somebody aligned with you and working in the same direction as you, usually bears a lot of fruit.

So for instance with the #24 and the #48 cars, when we first started this situation, we saw a big benefit of having the two teams under one roof. So the natural thing to have happened next would be to put the #5 and what was then the #25 under the same roof. We saw some benefits of bringing those two cars together, from a cost standpoint, a resource standpoint, and manufacturing to development - all that stuff.

The problem you get into when you start to combine those people is just like anything else. If you're in a relationship for a long time you start to think the same thoughts and you lose creativity. So having two buildings like that keeps that competitive drive towards each other and it keeps the engineering stimulated to where we continue to grow. If we were just under one roof I think it would really get pretty vanilla across the board for the four teams and we don't want that to happen.

Knaus led Johnson to his first title in 2006, and picked up some cool trophies © LAT

Q: How much of that layout transfers from your base to the track?

CK: When we're on the racetrack it's more four-by-four. It's a complete open-book form for all teams at all times, even at the shop. We have complete open policy from one car to the next, from one crew member to the next. There aren't any secrets. We try to help our team-mate and even once we're at the event and we start racing, our engineers are still communicating with one another about fuel strategy and pit strategy. We're talking about the adjustments that each team makes to their cars and how it affected the car and then how we can apply it to each other. It never stops.

Q: How much does each crew chief customise his cars? How different are, say, Jimmie's cars to Dale Earnhardt Jr's?

CK: If we figure out there is a better part, for instance, we'll run it in all four cars, then worry about making sure that we've got the right springs and the right shocks and the right aero-balance in our car. We'll worry about some of the things that have an impact on how we actually race as opposed to the mechanical aspect of it.

But that being said, if a crew chief says, 'no, I don't want to run that package, I want to run something else', that's his prerogative. We don't tell each crew chief: 'you have to run this'.

You're racing almost every weekend and testing is very restricted these days. How much simulation work do you do and how key is it?

CK: Right now we have our own simulation programme, Hendrick Motorsports Sim. We started it probably 15 years ago and it's grown. It's basically an Excel programme we've built here. It works really well. It comes out in a Pi data file, worked in Pi toolbox and can look at gradients, a balance sheet, dynamic wedge-type sheet, we can obviously look at the aero-balance of the car based on straightline testing and what we see for downforce and drag gains there. We rely heavily on simulation. With the lack of testing that we've got now, that's where we do most of our development.

Q: Without any suspension telemetry from race weekends, how do you correlate what you simulate with what you actually race?

CK: Post-analysis is really important to us. We go to great lengths to try to bring a racecar back to our facility after a race, put it on the seven-post machine and run it and get basic grip and travel numbers. We obviously know what we get for shock travel, just measuring with a tape-measure at the racetrack. We know how much or how hard the splitter is touching the racetrack or how much the rear skirts have travelled. We can go through all of that and put it into the sim and see how it correlates, so there's a lot of ways for us to verify it. But look, let's be honest, with the way the tyres and the speeds of the car change, to change 200/1000ths is pretty easy. So you have to leave a little bit of fudge factor in there until you get to the track.

Extensive windtunnel work keeps Hendrick cars (24, 48, 88) at the front © LAT

Q: How much aero simulation you do?

CK: We're in the windtunnel at least once a week. We've got the Windshear rolling-road windtunnel here, which is a really good tool to use. There's another one called AeroDyne and it's a good tunnel but it's not a rolling road - there are some effects we have to take into consideration rolling underneath the car because obviously the air is not moving at the same speed. It's a great tool for development. Then we also have our CFD work that we use. We hit every angle of aerodynamics possible.

Q: With strategy being so decisive at times, do you have simulations and software to rely on during races?

CK: It's really difficult - I'm not saying Formula 1 is easy but it's not the same. There are too many variables here. We have more cars that are competitive, probably 30 cars that can win the race. Nobody's following a format. Nobody's following a two-stop or three-stop race. They're doing whatever they can to win the race and to get themselves up front. So to try to say, 'your tyre fall-off is going to be there and then you're going to need to pit at this point to make sure that you've got the fastest times throughout the race' doesn't work.

The 'safety car' also comes out in our series way too much. It's a complete set of circumstance so you can't really use simulation to run your race strategy. We try to listen to what some of the other competitors are saying. A lot of it is just based on your gut.

Q: Almost 20 years after you joined Hendrick, what lies ahead for you?

CK: I don't know. The tape is still rolling. We just have to see. I hope there are opportunities for me to do things at Hendrick Motorsports if I like. It's a growing sport. There's no telling. I'd enjoy doing something like IndyCars, but to give up what I've got now, with the group of individuals that we've got, would be difficult to step away from.