Who doesn’t love a huge wheel stand? It’s a sure way to get your picture plastered on the front page of web sites and magazines alike. Though wheelies are cool, it’s definitely not the way to get down the track fast. Wheel stands are for fun and excitement, but not for getting the lowest e.t. and ending up in the winner’s circle.
As tire technology improves, and as engines make even more power, with today’s short-wheel base muscle cars, you’ve got a wicked formula for creating nasty huge wheel stands. Not only a safety device, wheelie bars become an important tool for controlling wheel speed on ever-changing track conditions. We hooked up with Chassis Engineering to install a set of wheelie bars on our Project Grandma Malibu, but we also talked to some top racers and chassis fabricators for their take on optimum wheelie bar setup.
It’s pretty simple to install wheelie bars: any good metal man or fabricator can throw together some bars for you that will keep you from flipping over. However, their design, construction, and setup is considered one of the black arts of drag racing: wheel base, power, tire size, and transmission choice are the main factors when determining the wheelie bar length, type (sprung or unsprung), material, and height.
Understanding Wheelie Bars
The first and most obvious reason for wheelie bars is to prevent a vehicle from flipping over during wheel stands. That’s the basic function. However, as you get faster, wheelie bars also become critical tuning aids, and can help steer the car as efficiently and effectively as your 4-link or ladder bars.
“The wheelie bars act like a rudder,” explained Clay Murphy from Chassis Engineering. “If you are on the bars and the car is going to the left or to the right, yet when the car is off the bars it runs straight, then you know your wheelie bars are steering the car. This is why you run a split, which can increase control with a car without a rear sway bar. In the first initial hit, you want to steer the car in the opposite direction of the lowest wheel. If the right side is low, it will steer to the right.”
Wheelie bars come in two main versions – sprung and unsprung. The upper tubes in a sprung wheelie bar setup act as a dampener as the car comes up on the bars. You won’t find sprung bars on a Pro Stock car because sprung bars are mainly used by small tire cars that produce a lot of power.
“With the small tires that are on the edge of traction, you want to soften the hit,” John Urist, four time NMRA Super Street Outlaw racer told us. “Because they are so close to spinning or even experiencing a slight slippage, a hard hit will upset the car.” The reason you generally don’t find a sprung bar on a large tire car is because the added rubber plus a taller sidewall will absorb the energy when the wheelie bars hit the ground.
Since we were selecting a good wheelie bar kit for our G-Body Malibu – Project Grandma – let’s take a look at Chassis Engineering’s most popular options:
Chassis Engineering Wheelie Bar Options:
50” Bar – The shortest kit from Chassis Engineering is designed for a Sportsman type car or a slower bracket car in the 9.00 to 11.00 ET range. Tubing features 1 x .065 wall that is pre-assembled and all tig welded. The K-member is on top instead of on bottom to help with getting a jack under the car.
84” Pro Stock Kits – This kit is designed for cars running under the 9-second range. It features 1-1/8-inch .083 chrome moly tubing and is a weld together kit. Recommended length is 64-70” long from center line of axle housing to the center line of the wheel.
84” Pro Mod – The Pro Mod bars are very similar to the Pro Stock kit, though they come with larger 1-1/4-inch .095 wall chrome moly tubing. There is also a couple extra stiffeners and cross braces in the center part of the lower set of bars. These are designed for 6.50 and faster cars.
Grandma Gets a Rocker – Chassis Engineering Pro Stock Kit on our Malibu
Grandma made test hits in the mid 10s on motor, but that will drop to low 9s or high 8s should we use the nitrous, so we decided she could use a wheelie bar hook-up before pressing the giggle gas button or upgrading the engine.
For a wheelie bar installation, you first want to determine the width of the wheelie bars for your application. Gently clean the rear end housing in the area where the brackets will have to be welded and make sure there isn’t any rust or grime. Find the center of the rear end housing on the bottom and mark it.
“The biggest thing is to make sure the brackets are welded on correctly and to also make sure the top and bottom bars have a big enough spread to not be an issue,” Murphy says. “Typically, we look for 10-12” of separation. You need to make sure you pay attention to how you mount that top bar to make sure it doesn’t hit the chassis when the car leaves the starting line, which will instantly unload the car.”
Next, measure half the distance of the total width of the wheelie bars from the center mark outward on each side. This will be where the housing brackets/tabs will be welded. Bolt the rod ends between the brackets for the correct width using the non-locking nuts and tack weld in place.
Chassis Engineering recommends using the cross bar on the bottom of the four link brackets because it will make the best mounting spot for the brackets when using a four link. If using a ladder bar, you must mount the tabs on the back side of the brackets or add a crossbar between the brackets for mounting.
With the car at ride height, you will need to measure from the lower mounting brackets to where you want the center of the wheelie bar wheel to be. Take this measurement and subtract 2-3/4” for the caster bracket and 2-3/4” for the rod end and tube adapter. Use this dimension to cut two of the 1-1/8” x .083” pieces of tubing to size. Cut at 90 degrees on both ends. These are now your main lower wheelie bar tubes.
Back at the work bench, match up the caster brackets to one end of each of the main lower tubes. When they are square and level, tack weld in place. With the bars still on the work bench, measure each bar from the center of the wheel up each lower tube 14” – 20” and mark both bars. This will be the mounting point for the cross bar.
Clamp the main lower bars down to the table with your desired width which you’ve carried over from the tabs on the rear end housing. Make sure they are straight and square. Cut and notch the 1” X .058” tubing to fit between the bars evenly with the marks made. Once you have the bar square and level tack weld it in place.
Cut and notch one of the 3/4” x 72” tubes to go from one of the intersections of the cross member and main lower tube to just behind the tube adapter at the upper end of the opposite main lower tube. Cut and notch the other 3/4” x 72” so that it forms an X from the other end of the cross member. Next, cut the 3/4” x 36” piece of tubing in half. Cut and notch each one to fit from the center of the cross member to the bottom of the main lower tubes just behind the caster brackets. Repeat for the remaining piece of tubing to form a V. Tack weld all bars in place when fit and placed correctly.
The hole in the top tabs that mount the top of the wheelie bars must be at least 10” or more higher than the hole in the lower mounts. The higher the brackets are from the bottom mounts the stronger the bars will be. Sand the housing clean and install the mounting tabs so both mounts are level to the ground and are the same front to back from the housing center line. Tack weld in place. It’s important to note that the top brackets can be narrower then the bottom.
With the car at ride height, install the rod ends half way and bolt the bottom bar to the rear end brackets. Install the wheelie bar wheels using the rue pins and rings. Place a prop under the wheels so you have about 6” from the ground to the center of the pin on each wheel. Also, make sure the bars are straight and in the center of the car. If they are not, the rod ends can be adjusted or the tabs can be moved.
Tack weld two of the remaining 1/2” tube adapters into one end of each 76” piece of 1 1/8” tubing. Then screw a 1/2” rod end into the end of each tube half way. Install the rod ends and tubes into the brackets on the rear end housing by just sliding the bolts into the holes in the brackets where you will let the bars hang for the time being. Screw the 1/2” x 3/8” rod ends into the other two tube adapters half way and pin them to the caster bracket tabs with the 3/8” quick pins using the lower holes in the tabs.
Hold the caster bracket tabs on the top of the caster bracket along with the top bar of the wheelie bars up next to the tube adapter and mark the length the bar needs to be cut at. Repeat this step on the other side. Slide the tube adapter with Rod Ends into the end of the tube. With the tabs still quick pinned to the rod end, line the tabs evenly with the edges of the tubing and tack weld in place. The tabs will be on a small angle to the center of the car if the top bars have been moved to the center of the rear end housing.
- “Mostly people ask how long they should make the wheelie bars, and we usually tell them to get the 84” bars and cut them down as they see fit,”
- “The longer you make the bar, the higher you need to make the bar when you start off. What ends up happening is that the shorter the bar, the longer the period of time it takes for the bar to hit the ground.”
- “In the 64-70” range, you can start with a 6-6.5 inch high and about a 1/4 stagger.”
- “While in the pits, chalk your bars to see how they are hitting the track on launch.”
- “When you get to the line, measure the bars on the starting from the ground to the center of the pin on the wheel, while pulling the bars up to take the slack out.
- “When you start going really fast, you use the bars to control wheel speed. As you raise the wheelie bar up, you take wheel speed away. Lowering it adds wheel speed. It doesn’t allow the wheel to compress as far, which allows the tire to spin. A good race track will make the car faster by lowering the wheelie bars, but as the track goes away, raise the bar.”
Setting Up Wheelie Bars – Racers & Tuners
Wheelie bar height is personalized; there isn’t any exact way it should be done. “There’s no formula, it’s just years of experience,” Bickel says. While this is true, there are a few fundamentals when it comes to basic setup.
Metz: “I’ve got some cars that have long bars that just hit the bars and flex some. I have some cars with springs in them. Then I’ve got cars with good weight splits where I can run what I want.
The biggest reason people change length is so it doesn’t upset the tire when it hits the bar, especially on a small tire car. A lot of guys get by on a shorter bar if they go with a really good upper sprung bar. Having the sprung bar on the small tires keeps it from hitting so hard, since they are already running on the ragged edge (and also a smaller side wall) of traction for that tire. Also, you want to set the bars a little higher to let it transfer a little more weight.
If it’s a big tire car, you should run solid bars as long as it has half way decent weight splits. With a ten inch tire car, you’re going to run a solid bar a little bit longer to flex a little bit and transition easier. It doesn’t let the car get the tire up over center and lift the tire; the longer the bar, the more it wants to drive the tire into the track. Don’t put them so high that it’s rattling the tires. On a big tire car you will set the bars lower, because you have that additional tire width. You also want to look at the tire’s roll out.”
On a race weekend with Troy’s Pro Street Car, how important is the wheelie bar tune up in the big picture?
Metz: “The wheelie bars are everything. If you miss on the wheelie bars and the car goes left or right hard, there goes your run. Also, buy quality wheelie bars. Regardless of where you end up running your bars, quality bars is important. Good bars are going to give you more consistancy.
Knowing that you mainly work with high horsepower combinations, do you even use sprung wheelie bars anymore?
Musi: It’s probably been thirty years since I have run sprung wheelie bars. In my opinion, sprung bars are only good for keeping the car from flipping over. The wheelie bars have a purpose.
In a clutch car, we use it to get the tire to spin sometimes or keep the tires planted. We want to strike the bars for 8-9”, get off them, and get the car to get up on the tire, and then it will get back on the bars about 8-9” later. When we release the clutch, we want the tire speed.”
What’s your take on wheelie bar stagger?
Musi: You have to be very careful on stagger. A lot of guys I see don’t stagger. We run as much as 3/4” stagger, with the left bar up higher. You want the right bar to hit first because that’s how the car naturally wants to hit. If you get that left bar too low, it will want to go left on you every time.
Working mainly with Pro Street and Pro Mod cars, what length wheelie bars to you like and how do you set your height?
Musi: On a Pro Mod car, you want a longer bar for a little bit of cushion. You can get too long where you shake the tires and you break them worse than anything you can imagine. A lot of them use bars in the 80” range, where a Pro Stock car will be in the 60s. The Pro Stock cars depend a lot on the wheelie bars for determining wheel speed according to the track. A short wheelie bar we will run about 5” on right and 5.5” on left. On a Pro Mod it might be 6” on right and 6.5” on left. I would start a little higher. If you’re too low it can hit really hard. Watch how the car gets up on the tire and then bring it down accordingly.”
On a race weekend, how important is the wheelie bar tune up in the big picture?
Musi: 25% of it is the tuning ability. With an automatic car it can be very critical because you’re limited on your tuning ability on the starting line. With a clutch car, you can work with slipping the clutch and launch RPMs.
Some people tune their bars to lightly touch the track as they make their way down, and some people only use the bars within the launch pad. What’s your take on that?
Bickel: “If the wheelie bars touch the ground, the car is losing tractive force. If you see people dragging the wheelie bars, the weight is over the bars, and not on the rear wheels. The wheelie bars need to touch the ground for 12-18” and never touch the ground again. In cars with more horsepower that leave harder, the longer wheelie bars seems to have more leverage on the chassis and are more gentle when leaving. But then you get into having problems of heavy wheelie bars with unsprung weight that you want to stay away from.”
Why do you see blower cars with only one wheelie bar?
Bickel: “Blower cars have more power and torque, but they bring it on slower and slip the clutches more. They aren’t as dependent on wheelie bars for keeping the car straight. A nitrous car wants to hit the tire hard and uses the wheelie bars to help steer the chassis in the first 10-15 feet by dropping the right wheelie bar down lower.
How do Wheelie Bars work Jerry?
Bickel: “If you ever take a drill and hold the trigger down, it doesn’t offer any resistance when it’s running. But then when you release the button and push it down again, it jerks your hand. That’s what wheelie bars do, they take out the jerk of your hand that your engine and transmission combination produces when you lift your foot off the clutch or pull your finger off the trans-brake. The car, for a moment, will put out more power to the rear wheels than it’s capable of producing because you have all that inertia built up. That’s what the wheelie bars do, they have to overcome that.”
John, you’re trying to put a lot of power through a small tire and we see that you run a sprung bar. How does that help you?
Urist: When you go with the sprung, you take the spring into consideration when setting up the bar height which I feel is a lot better in our small tire situation. With the sprung bars, we will set the height at about 7 inches and then they go will up to about 10 inches with the spring. With being a Procharged car, we use timing and launch RPM mainly to control the power delivery off the line, depending on the track conditions. We haven’t been on the bars much this year. So far we have just really been using it as safety.
Steady Your Course With a Good Wheelie Bar Combination
While the idea behind wheelie bar design is rather simple, proper adjustment is crucial the faster you go. Chassis Engineering supplied us with a rigid, easy to install kit that will make adjusting our bars easy. They also offer multiple kits for various vehicle applications. So the next time you’re at the track, think of the important job those little wheels do for keeping race cars safe and straight.