By on September 18, 2015

Rear shot LSPR

Andrew Comrie-Picard, also known simply as ACP, is a rally champion and team owner, stunt driver, TV host, former Pikes Peak International Hillclimb record holder and BFGoodrich tire spokesman.

We asked him about his experience in rally, how he sets up cars and how it pertains to road cars.

ACP at GTAQuestion: You learned how to drive on back roads in Canada?

Answer: Yeah. I grew up outside Edmonton, Alberta, on a dirt road. We had acreage and a field. My dad had a trucking company. I learned how to drive on an old Ford pickup. I was sliding that around the fields and that’s how I started.

Q: Obviously, you know rally setups — you ran your own teams. How much of that world is applicable to the real world?

A: We often say “real cars, real roads, real fast.” Compared to other types of racing where you have more rarified equipment, rally racing takes production cars and drives them down manufactured roads — roads made by people to drive down. Sometimes those are logging roads, cottage access roads, mountain roads or twisty roads.

So you’re taking normal cars, finding the most difficult roads, and running flat out. So, in a way, it’s the most ultimate real-world test of real-world engineering. We have to operate within the confines of a production chassis: suspension arms, suspension travel. We fit upgraded shocks and some upgraded equipment for high-speed stuff. In terms of alignment, we set up for predictability. There’s a lot of crossover between what is good in a production car and what’s good in a rally car.

Q: How so?

For example, all cars are sensitive to toe. Whether it’s toe-in or toe-out or zero toe. (Imagine looking at your own feet, whether they’re pointed in at each other, out away from each other or straight ahead.) If your wheels are pointing straight forward, the car actually tends to wander on freeways; the cars move around. Most production cars have a fraction of toe-in. The problem with that is it makes your tires wear slightly faster, but it gives cars a more generous on-center feel and makes the steering wheel a little more predictable.

That’s one thing that we carefully adjust in each rally car — we look at the toe. It can really affect how quickly the car turns in and out, and how predictable it is. I like to run my rally cars with zero toe, front to rear — generally speaking. That gives me the best combination of turn-in and high-speed stability with little resistance.

However, in ice rallies, where traction is unpredictable and at a premium, we’ll toe out the front and the rear. Toeing out the rear makes the car super sketchy. You’d never want to do it in a production car.

Q: Define “sketchy.”

A: Take your feet and point them outward — or, if you’re a skier, point your skis away from each other. It’s an inherently unstable setup. If you toe out the rear, it’ll always want to overtake the front. How “tech” do you want to get?

Q: I think our readership can handle tech.

A: Let’s geek out then.

If you toe out the front of a car, it’ll dart in the direction that you point it next. It’ll be very touchy — very good on a racetrack, very good in a rally, but never good on a public road.

Toeing out the rear of a car is even more sketchy because the rear always wants to overtake the front, but on snow and ice, when you’re always trying to get the car to rotate, we’ll add a degree or two of toe out front and rear.

The problem is, running at 100 mph with toe out is a real attention-getting exercise. The car wants to go anywhere but straight ahead.

The real takeaway is that production cars — like rally cars — are super sensitive to suspension adjustments.

Let’s talk about camber and castor — is that too much?

Q: No way. Let’s geek out.

A: Race cars usually have a few degrees of camber. You do that to align the tire for high lateral grip. That outside wheel, that has two or three degrees of camber, stands straight up.

You want to get that beautiful moment where that big, wide contact patch is in perfect harmony with the ground. That’s the whole point.

The downside is that when you dial in that much camber, braking is effected. It’s always a compromise.

That’s a big deal for somewhere like Pikes Peak — it’s all tarmac. We can get a lot of grip, but we have super important braking zones. If you screw up a braking zone, you go into clear air 5,000 feet off the ground. But, at the same time, you have high-speed corners where you’re going 140-150 mph and you want to lean up on those outside wheels — it’s a serious trade off.

In gravel rally, it’s not as important because we have less traction there than on tarmac. We never actually roll the car over on that one side.

This is really nerdy: You’ll notice that rally tires have a real sharp, real defined edge. That’s meant to cut through the gravel in a slide and dig the tread into the ground. Rally tires have a built-in sweeper. If you camber that tire in too far, you skate up on top of those rocks rather than digging in.

They also need to be resilient. Last season when we won the rally championship (Rally America 2WD Class) with Ford on BFGoodrich tires, we had no flat tires. That’s almost unheard of.

Q: Say you go buy a car, and it’s a family car. What do you inherently want to do to it, immediately?

A: It’s interesting you’d ask that. I’m a real believer in “horses for courses.” You can optimize a car for all sorts of circumstances. If you want to take a production car, slam it down, put on wide tires, add in some camber, that’s great if you have billiard-flat roads. If you don’t have enough suspension travel to take in some features on the road, people don’t realize, you don’t sacrifice comfort for performance — sometimes you’re compromising performance.

If you look at rally cars over the last three or four years, our suspension is really soft. The cars move around a lot. The more a suspension can compress and move around, the easier it is to drive. You can get more progressivity out of the suspension, the more you can move that car around.

Imagine you’re a skier or snowboarder, imagine trying to sky with your knees and ankles locked together. It’s much easier to move when your knees are dynamic, and moving around.

Q: When does soft become too soft?

A: You’re talking about an engineering philosophy — and it’s an old philosophy now — that a car is engineered to be very unforgiving at the limit. All the driver has to do is his job, right?

Often those cars are set up on a very, very sharp edge.

We talk a lot about progressivity at the slip limit. If you think of a graph of slip angle vs. lateral load, a sharp tire will have a ton of grip until its limit and then drop off and it’s very hard to collect. A more predictable tire may not have such a high limit — or an ultimate level of traction — but it’s more predictable at its limit.

Same goes with a car. The fact of the matter: Most drivers are better with a car that’s more predictable. Even if you’re giving up a tenth or 4 percent or 5 percent of the car’s ultimate ability.

Take a Prius at one end of the spectrum, which has lots of understeer — very safe and predictable. Take a Formula One car at the other end of the spectrum — very fast, but very unpredictable. No one is drifting a Formula One car because it doesn’t work like that.

Rally cars are somewhere in the middle. We’re going down a dirt road at 100 mph with little traction. We set up our cars to be very predictable because we’re improvising a lot of the time.

In rally, we’re taking real-world circumstances, real fast. I prefer a car that’s set up for all circumstances and is very predictable.

Q: When you talk about high-performance, it sounds like you could be talking about safety too; predictability and compatibility for all kinds of roads. If you don’t give a damn about performance — or you don’t know that you do give a damn about performance — how do you make a car work the very best it can in your own backyard? Considering that they sell the same Prius in Arizona that they do in Washington.

A: I actually see a very close relationship between performance and safety. If you’re confident in your driving, you’re going to be a safer driver.

It’s one of the design philosophies of BFGoodrich. That’s why I race on BFGoodrich, because they’re very predictable. That’s ultimately what you want. You don’t ever want to be surprised.

In terms of setting up a car, any civilian who’s looking to get the most out of their car without racing should basically always go with manufacturer set ups. Have your alignment checked at regular intervals, or if you smoke a curb, check it then. The difference between a properly aligned car and a bad alignment is huge.

Keep in mind that the engineers who worked on that car know the alignment, the suspension travel, the arch of the wheel travel. If you start diving in on that, you open up a whole Pandora’s box.

Q: You’re assuming you know better than millions spent in R&D?

A: Right. Those guys in Stuttgart know their shit. I know you know your stuff, but for these guys, it’s a full-time thing.

Having said that, I own a 1982 Porsche 911 Turbo that I drive on the street in LA. In the summer, I drive it on full, R1 race slicks. It never rains or snows, so it’s not an unreasonable choice.

After a panic stop or two on the 405, I feel that 35-40 year old car is a little under-tired up front. So I went from a 225/55 to a 245/50. Essentially 20 millimeters of difference to get a bigger contact patch. We know from camber, suspension and everything else that’ll change the car. Twenty years of racing, I know that it needs a little more braking.

I also know that affects the brake balance in that car and oversteer/understeer in that car. So I needed a proportionally wider tire in the back too.

There’s the only adjustment that I’ve ever made to a street car.

Q: It’s fair to say you know what you’re doing, I suppose.

A: I’ve raced a car or two.

Q: What do you tell students — drawing from your rally history — who’ve never heard of rally, to be better drivers?

A: There are a handful of really simple things:

  • Always look as far ahead on the road as you can. It’s been my experience that drivers look directly in front of them. That’s letting the road happen to you.
  • Be “automotively empathetic.” I want everyone thinking about what everyone else is doing. That gives you more margin to understand what’s going on.
  • Look for wheels turning in a car that’s moving. You can’t tell who’s moving relative to the background, because you’re moving relative to the background.
  • If I could give everyone the ability to feel weight transfer, I would. Every good driver transfers weight smoothly, with gentle inputs, on tender hooks.
  • Advanced tip: If you’re going to a track day, understand your traction circle. You only get a finite amount of “units of traction.” If you’re braking, you’re using a certain number of units of traction. If you’re turning, you’re using a certain amount. Imagine a string attached at one end to the bottom of the steering wheel and at the other end to your brake pedal. When the steering wheel turns, the brake comes up. When the brake goes down, the steering wheel winds out.
  • Also, I’ve won every winter rally/ice drive in the country. You need winter tires.
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18 Comments on “Andrew Comrie-Picard Q&A: ‘If It’s Good for the Road, It’s Probably Good for Rally’...”


  • avatar

    I honestly have no idea what Rally car racing is and I pay 0% attention UNTIL there’s a spectacular accident.

  • avatar
    skitter

    There are no pictures in these comments, right? Okay, imagine a huge cheer rising from a tidal wave of gearheads in the stands of a racetrack or on the stage of a rally. Okay, a picture is worth a thousand words, and I’m at… forty six… I’ll just clap a lot.

  • avatar
    CoreyDL

    Sweet Fiesta rally pic!

  • avatar

    FYI, he’s also a TTAC alum from the old days.

    https://www.thetruthaboutcars.com/2006/11/mitsubishi-evo-ix-mr/

  • avatar
    Lou_BC

    Great interview. It is nice to see a linkage between racing and street driving.

  • avatar
    tedward

    I’ll disagree with him on one point (loved the article but that’s what comments are for). He puts waaaaay too much stock in manufacturer tuning of mass market cars. While Porsche likely specs specific suspension setups for various trim levels your average focus, civic, whatever has the exact same suspension regardless of tire width, rim diameter, tire compound, and aerodynamic add-ons fitted to the various trim levels. So, no, your likely car probably doesn’t have a finely tuned suspension built to fit the components exactly. Some euro market models (applies to some domestics too I think) will allow you to spec one of several spring rates, while making no changes to sway bars, tire geometry or damping. The OEM tuners of these cars also have a priority list that does not conform to what most drivers would want necessarily. They have component cost, worst case road condition scenario in your market (the US is a huge market geographically), assembly cost, and differing subjective measures of comfort to appeal to. In short, you can often do better unless your specific car is designed specifically for your exact driving condition, and you don’t know that unless you were on the proving grounds and in the lab with the OEM guys when they set it up in the first place.

    The best you can do is to keep in mind the setups available from the manufacturer on your particular chassis (treat the highest trim levels tire width as a rough guide to maximum recommended, same for ride height vs. control arm angle, tire geometry etc…) Also, keep in mind that not all suspension engineers put out equal quality product, and that there is certainly corporate, and not necessarily well informed car-knowledgeable corporate, influence on what they produce.

    • 0 avatar
      heavy handle

      That may be true for some manufacturers, but not for all. I know that my Saab has something like 8 different SKUs for front shocks, and rear shocks, and front/rear springs. You need to look-up a secondary code on the VIN plate under the hood when ordering replacements.

      I imagine that the types of cars that one would rally, like a Focus ST, GTI, STI, Abarth, etc, have specific springs, dampers, roll bars, brakes, and sometimes control arms (not to mention wheels and tires).

      • 0 avatar
        tedward

        Yeah I don’t doubt it isn’t universal. Saab in particular was famous for economies of scale destroying attention to detail. And those dedicated sporty models are running unique damping and sporting rates, but aren’t in the normal trim ladder. I’m referring to someone buying a base model vs a higher trim level, there’s going to be a huge jump in tire section width and rim diameter there. As much as three to four inches of rim typically.

  • avatar
    Petra

    Fantastic article. It’s articles like this that keep me coming back.

  • avatar
    CJinSD

    I was hoping he would discuss castor.

  • avatar
    MBella

    I really enjoyed this article, and hope to see more of them.

  • avatar
    S197GT

    loved this. great article. one of my big pet peeves is how you get an alignment but they don’t give you the before and after printout unless you ask for it.

    definitely safest to stay within manufacturer specs but there is usually some room to play with; though you may not be able to dial in much adjustment w/out aftermarket parts.

  • avatar
    VolandoBajo

    Good article, but with a couple of orthographic/editorial shortcomings.

    It is “caster” not “castor” when referring to suspension angles, and it is “tenterhooks” not “tender hooks”.

    Otherwise, an article that is both interesting and informative. But I also wish you had covered caster with him, as well as camber and toe.


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