How to make your engine faster. Part 1

Neil Fri Sep 26, 2008 10:34 pm

I would like to start contributing to the “Tech Talk” section. Before I get going, I would like to throw out a disclaimer. I, in no way think that I know everything nor do I think that my word is the last say on any subject. With that said, I welcome you to make comments, corrections or disagreements. I want you to participate with me, and in that way I hope that I can make your Kart racing a success. So, here we go!

The goal of every Karter is to win. In order to win you have to go faster than everyone in your class. We all too often blame a poor finish on a slow engine. Fastest lap times don’t come from just having the fastest engine. Chassis setup is where most of our success comes from. So, let’s talk about the front-end toe setting first. You are probably saying how can the front end make the kart go faster? For starters, if the toe in or toe out of the front tires are too great. In other words if the tires are pointing away from each other (toe out). Or the opposite, (toe in) if the tires are pointing in towards each other. Both conditions will cause the tires to scrub to a certain degree, and that will rob the engine of power thus slowing the kart. To correct this condition, you need to know what the kart manufacturer recommends for the toe out setting. I say toe out, because that is usually the static setting used without a driver in the kart. As the driver gets into the kart and loads the chassis. The tires will usually toe in slightly. It is therefore important to know how much the toe setting changes, when the driver gets in the kart. At that point the tires should be pointing straight ahead, and no scrubbing down the straight-aways.

How do we accomplish this? There are two ways, the easy way and the not as easy way. The easy way is to look at the manufacturer’s recommended toe out setting. The not as easy way, is to sit the driver in the kart and adjust the toe to 0. Then with the driver out of the kart, check the toe again. The toe out reading you get is the static setting. Now, you can check the toe out at anytime, without the driver being present. Special lasers and straight-edge beams are all designed to make setting the toe an easy, quick and accurate task. But, I still do it with a tape measure. Here is how I do it. I purchased a pair of metal discs that bolt to the front hubs in place of the front wheels. The discs give you an accurate edge to read the tape measurements. The least expensive (cheapest) way, is to rotate the front tires while holding a pen or sharpie to the center of the tire. Then measure from line to line at the front of the tire and at the back of the tire. Subtract the difference and you have your toe out measurement.

All of this measuring is for not, if the front wheel bearings are not adjusted properly or worn. Also by forcing the front tires together by hand, you can feel if the tie rod ends are loose or worn. Shake the top and bottom of the tires to check the spindle bearings for looseness or wear. Everyone that reads this thread should check their tie rod ends. If you started racing that kart at the beginning of this year, and have not maintained the front end until now. You probably will be able to detect some amount of play in the rod ends and wheel bearings. Any amount of play is enough to alter the toe measurements.

I have left a lot of openings for you to jump in with your comments, questions or disagreements. The goal here is to make your kart a hundredth or a ten of a second, a lap faster. Multiply that by 8 to 15 laps and by the end of the heat or main you can be a second and a half out in front. In the coming months I will talk about other ways to free up another tenth of a second a lap. So stay tuned, and keep that old engine. It might be faster that you thought.