|Adjustable Progress Group bars here. The forward holes make the bar softer, the rearward holes make the bar stiffer|
Typically you want to run a set of bars that is about 20-50% stiffer in the front than the rear. Adjustments typically make a 10-30% difference in overall roll stiffness so you can really change the feel of the car through bar adjustments. Typically with reasonably sized bars about 30-60% of the total overall roll resistance comes from the bars as well. This is one reason why drifting a car with swaybars is so much easier because the car responds faster and is more predictable due to the bars contributing to a large percentage of the car's overall roll stiffness.
|The Scion TC driven by Tanner Foust used Speedway Engineering bars.|
Adding or subtracting rear roll stiffness makes the largest difference in drift car chassis set up. A banked course like Irwindale, Monroe or the Wall needs more rear roll stiffness than a flat course like Long Beach or Vegas. Adjusting the bars is a lot faster than changing springs.
|Matt Powers S14 uses Progress Group bars.|
When running bars you can control body roll while running softer springs. Softer springs give you more overall traction and forward bite, important once you start hitting more advanced levels of drifting. Properly adjusted bars also make the car less twitchy and less likely to suddenly straighten up while in drift.
|The Scion TC driven by Fredric Aasbo uses Speedway Bars.|
When setting up your bars, be sure that they do not bind or contact the chassis as the suspension strokes through its travel. This sort of stuff can make the handling very unpredictable. Sometimes you might have to adjust end links or make spacers to put under the bar mounts to make sure this doesn’t happen. Taking care to do this makes all the difference in the world.
|If no one makes an adjustable bar for your car, you can cut the ends off and have a fabricator make up some plates with holes in them and weld them to the ends of your bars to make them adjustable. We know this is a FWD car but that's what we did here to make these bars adjustable, it's just an example.|
Sometimes people remove the front anti sway bar because it interferes with steering angle, the front tires hit it when turned full lock. In this case it is better to extend the lower control arm so they won’t hit anymore. It is not good to stack a bunch of front wheel spacers to do this because it hurts the scrub radius which opens up another whole set of problems. Making the lower control arm longer gives more negative camber and you will have to refiddle things to get proper camber. We will discuss this a little later.