Broken Throttle Parts – Loss of throttle is a common cause of a race car losing power abruptly. The throttle shaft can shear off, the connecting bolt can break or loosen or the linkage can just fatigue and break somewhere between the gas pedal and the carburetor. This is another area where we seldom do proper inspection and don’t discover there is a problem until we have a failure.
Properly attached and adjusted pedal stops can help prevent stress on the throttle linkage and carburetor shaft. It is not a good idea to use the carb. throttle stop as a pedal stop. Take time to adjust the linkage so that you will be applying full throttle (butterflies wide open with maximum pedal throw), but not stretching and stressing the linkage.
Shocks Bottoming Out or Over Extended – A radically errant setup can often be traced to a mechanical binding problem. Often, we find that a shock is either bottoming out from excess travel or hanging in rebound from too short a useable travel due to improper mounting.
Once you have finished building your car and have established the ride heights, measure how far each shocks shaft extends into the shock body. If you know the range of travel of the shock, you can subtract and know how much rebound, or compression, travel you will have available.
Suspension Binding – Another source of mechanical binding lies in the use of sliders in some cars. The various designs of coil-over eliminators and big spring sliders need constant maintenance. Follow the manufactures recommendations and inspect these units often. They will bind up and stick if not properly maintained, especially on dirt cars.
Most race teams that ignore this important task will experience a car that slowly fails to respond to chassis setup changes. This is a clue that maybe you need to look at beginning a maintenance schedule.
Broken Shock Mounts – The mounts that hold your shocks on the car take a lot of abuse in all forms of circle track racing, especially with the coil over types of suspension designs. One of the worst failures you will encounter is a broken shock mount. This cannot be fixed during a race.
Regular inspection of the metal around the mounts can often show the start of a crack or stressed area so that we can re-weld or replace the mount. This exercise can greatly reduce the chance that you will loose a shock mount during a race.
Loose Bolts – The suspension parts endure a lot of force from braking to acceleration. The control arms at the front and the ends of the rear links can become loose as the bolts are pushed and stretched lap after lap. If these loosen during a race, the car will become un-drivable.
If your car is doing strange things, one of the first and easiest things to check is for a loose bolt in the suspension system. Even if the joint is fairly tight, but not real tight, it can slip and result in a rear end that is out of alignment, a serious problem none-the-less.
Bent Axle Tubes – A bent rear axle tube can cause toe and camber problems. The bend could be in any direction to affect toe, camber or both. A set of rear wheels that are toed either in or out excessively can cause the rear end to lose grip all of the way around the track. Sometimes the cause can go un-noticed.
Common causes are a brush with the wall or contract with another car. When either of these happens, make sure to check the toe and camber at the rear wheels. We often concentrate on front wheel toe and camber settings and forget that rear wheel geometry is just as important.
Plumbing Problems – How you plumb your car for cooling the water or oil can be a problem. There are some common misconceptions about these two that can cause overheating and/or engine failure. Here are a couple of common mistakes teams make.
When plumbing your water lines, remember to install a proper sized pulley on the water pump so that the speed will not be too slow or fast. It is a general rule of thumb to match the pump pulley size to the crank pulley size.
In plumbing a dry sump system, always place the filter where it will be the last thing the oil passes through before entering the motor. If not, lots of unpleasant things can happen. New radiators with internal oil coolers often have slag and other pieces left inside that come loose and flow into the motor if not filtered out. Placing the filter before the radiator could be a problem.
Flow the oil through the radiator oil cooler into the bottom and out the top. This pushes any air that may be trapped in the unit out to prevent cavitation. Use hose ends that are the free flow design where the bend is made with tubing and not an abrupt ninety degree turn drilled into a solid aluminum block.
Conclusion – If any of these examples spur you and your team to action and helps you to avoid a costly jinx, then we have done our job. We can always learn from the experiences of others and that is exactly where these stories and examples come from. All of these mistakes have happened in the past and will happen again. Jinxes don’t come out of thin air, but rather from our lack of knowledge and attention to detail. That makes them avoidable.
Sources:
AFCO Racing
www.afcoracing.com
800-632-2320
Allstar Performance
www.allstarperformance.com
269-463-8000
Coleman Racing
www.colemanracng.com
800-221-1851
Day Motorsports
www.daymotorsports.com
800-543-6238
Design Engineering Inc DEI
www.designengineering.com
800-264-9472
DMI / Bulldog Rear Ends
www.diversifiedracing.com
717-397-5347
Frankland Racing
www.franklandracing.com
888-873-2736
Intercomp Racing
www.intercompracing.com
800-328-3336
Harbor Freight
www.harborfreight.com
800-423-2567
Integra Shocks and Springs
www.integrashocksandsprings.com
800-472-3464
Jones Racing Products
www.jonesracingproducts.com
610-847-2028
Landrum Performance Springs
www.landrumspring.com
(574) 353-1674
Optima Batteries
www.optimabatteries.com
QA1
www.qa1.net
800-721-7761
Quick Performance
www.quickperformance.com
515-232-0126
PitStopUSA
www.pitstopusa.com
866-722-3432
RE Suspension
704-664-2277
www.resuspension.com
Rod End Supply
www.rodendsupply.com
800-284-2902
Smileys Racing Products
www.smileysracing.com
866-959-7223
Speedway Motors
www.speedwaymotors.com/CT715
855-313-9175
VDL Carburetors
www.vdlfuelsystems.com
251-443-5990
Wilwood Motorsports
www.wilwood.com
805-388-1188
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