Let’s look at when to use positive or negative camber in kart racing. Now the first thing is what is camber? That's changing the angle of the tire. As you are looking at it from a top-down point of view, if you've got the tires pointing towards the inside of the kart, that's going to be negative camber. If they're pointing towards the outside of the kart, it's going to be positive camber. What we see with racing cars is, they've got suspension, so you're going to notice their tires are pointing towards the inside, towards the chassis or the frame of the car. That's going to be negative camber.
Now, the instances where you might want to use negative camber is if you've got a lot of front steer negative camber tends to generally take away a little bit of steering, but it tends to put a bit more grip on the back of the kart. We typically see this used more in our high performance categories where we need to have that balance between the front and the rear. Also, with the speeds that we're traveling at, it's about having a decent amount of steer, but also having rear traction for a good balance.
The second instance where you might want to use some negative camber is looking at the tire compound that you're using. Now some tires, if we're looking at say an MG tire, they might be a little bit squarer in the front tire. Then you've got some tires like the LeCont or the Levanto tire. They're a little bit rounder in shape. If you've got a rounder tire, you can use more negative camber because you're trying to tip the tires inwards to use a part of the tire that's not really being used when it's dead straight.
When we're looking to adjust, I would say that if you're fine-tuning your front-end settings, a one mil adjustment is good. It's very hard as a driver with limited experience to necessarily feel one mil of a change. I would say when you're starting out, or especially on a practice day, it's good to go to probably two mil per time to make the adjustment. At least that way the driver can say, "I could feel a difference," whether that's good or it's bad, but at least then you can fine tune from there. Like I said, at one mill increment, it's very hard to know whether there was much of an adjustment or not.
When we're looking to our positive camber, that's going to be better suited for our squarer ties. Like I said, MG tires, if they have a squarer front tire, then basically you're trying to stand that tire up so you're using the full face of the tire. I tend to use a bit more positive camber with our low performance classes. You probably only need maybe one mil of negative camber in a low performance class. But you get into shifter racing or X30 racing, and that might be four or five mil a side of negative camber per side.
Now with our positive camber, you might only need to run one or two positive camber per side, but don't forget that when you are sitting in the go-kart, the tires tend to go towards the inside as well. If you're running at two mil of positive, by the time the driver sits in the kart with that body weight, it'll probably be at square, just at zero camber.
I always set the front end on the trolley, so I don't set it while I'm sitting in the kart. We just tend to set them up, whether it's two mil positive, zero, two mil negative, we don't sit myself in the kart with that body weight.
I hope that helps when you should be looking to use negative camber compared to positive camber. If you've got a lot of under-steer in the front end, put in more positive camber because as you start to take away, or as you add more negative, you're starting to use less of the tire.
That's going to probably exaggerate the under-steer. On the flip side, if you've got a lot of initial point, it's just so twitchy in the front end that you want to just take some of that front steer away, then just in two mil increments start to go into the negative camber.
That's a little bit of information on when you should use a negative and positive camber. If you guys need to know more information on your kart setup. We have our kart set up program that tells you when you should be looking to make certain adjustments.