The offseason is a perfect...
The offseason is a perfect time to take a good look at all the systems on our race cars. Much needed maintenance and repairs can be performed without having the pressure to get it done quickly.
After a hard year of racing, race cars are ready for a good looking over, a deep cleaning, and some much needed repair work that might not have been evident during the season. This is the time to tear down the car, remove all the mechanical systems, and do a thorough cleaning and inspection.
Let's face it, most racers love the "working on the car" part of racing as much as the actual racing. It represents most of the time spent racing anyhow. So, once the season has ended, it can be a lot of fun to go over the car and make sure it is put in perfect condition to start the new season. If done right, you can end up with a good-as-new car.
You should go through the car in a systematic way, overlooking nothing mechanical that may need some attention, from the replacement of worn parts to the repair of damage from hard racing. Start with the front and work toward the rear.
With the engine out and the...
With the engine out and the front fenders removed, many of the car's systems can be accessed. Take this opportunity to check every part of the car and perform maintenance.
Preparing the Car For Inspection The first step in this process is to remove the engine, transmission, radiator, exhaust system, fuel tank, and any body parts that will be scrapped. You can proceed to clean the car once those components are out of the way.
We recommend using a portable power washer to remove all the dirt and oils on the frame and body parts. Choose a site outside the garage, where you won't make too much of a mess. Spray around all the tubing on the chassis and under the car, where you have run over someone else's oil. Try to get to the rubber tire pieces that have accumulated during the season.
This thorough cleaning is done not only for appearance purposes, but also to inspect the welds and other joints on the frame and rollcage for any fatigue or cracks. Broken welds, cracked frame members, and broken shock mounts account for lots of on-track failures, and this is a great opportunity to find those flaws.
The lower control arm supports...
The lower control arm supports the weight of the front of the car. Make sure the shock mounts are not fatigued and that the bolt and spacers are in good shape. Now is the time to replace worn bolts and nuts.
Front Suspension You should remove all the control arms, steering assembly, spindles, and so on if that wasn't done before the cleaning. Then, lay the parts on the garage floor and carefully inspect each one for any signs of cracking, bending, or breaks at the welded seams.
Remove the Heim joints, ball joints, and idler arm assemblies (on a drag link system) to test for excess looseness and wear. Replace the joints that are worn. Check the steering box or rack for excess play and worn seals. This may be a good time to overhaul the steering or send it back to the manufacturer for a rebuild.
Inspect the engine mounts, front hoop tubing, upper control arm mounts, and any areas where fatigue might have caused cracking or breaking of the metal. Once the inspection is complete and all repairs have been made, it may be a good idea to paint the front clip. If you plan on doing a complete repaint of the car's frame, do the rest of the inspection first.
Check all the steering components....
Check all the steering components. These are hard to get to with the engine and radiator installed, so take this opportunity to do a thorough inspection and maybe a rebuild.
Shock Mounts While the front of the car is apart, do a close inspection of the shock mounts on the upper mounts as well as the lower control arm. This is one area of high stress that needs attention. If you see signs of cracking or breaking, rethink how the shock is mounted and do some re-engineering to better support the shock to reduce fatigue.
Some typical problems stem from the upper mount flexing on the tubing to which it is attached. Every stock car that uses coilover shocks should have a crossbrace that attaches to the upper shock mount, or as close as possible to it. This brace reduces the flexing and rotational twisting of the tubing where the shock is mounted.
Even with stock spring designs, the shock is still working hard. It is attached to the upper hoop bars. When mounting shocks on stock clip cars, the procedure used for coilover shocks should be employed.
The shock mounts carry a lot...
The shock mounts carry a lot of load, so inspect them and replace the bolt that has been cycled many times over the course of the season during numerous spring changes. Note the bracket for the crossbrace is located near the shock mount, where it should be.
Lower Control Arms The ball joint sockets and the inner mount portions of the lower control arms (or struts) are the most stressed areas of this part, aside from the shock mount. Pay attention to the overall condition of the arm and look for fatigue and cracking around the mounting areas.
Check the arm for straightness as well as fatigue areas. If the car has been in contact with other cars or the walls and the arms have not been replaced, there may be hidden damage. Now would be a great time to order new arms.
Engine Mounts This is another area where there may be hidden damage. Any sudden stops, which may otherwise not cause serious damage, might have bent or cracked the engine mounts. The motor is the heaviest piece bolted onto the car and the mounts are mostly engineered to reduce rotational movement, not fore and aft movement.
Front and rear end hits can cause damage to the motor mounts. A good inspection of these mounts is not possible with the motor in the car, so now is the time to look them over in detail. If you have had to space the motor up a significant distance to avoid having the oil pan scrape, now might be a good time to raise the actual mounts so there is less spacing needed. Doing this secures the engine and causes it to resist fore and aft movement by using fewer spacers.
If you need to raise the engine...
If you need to raise the engine using multiple spacers, now might be a good time to raise the engine mount to avoid having to space up so far. This makes the engine more secure.
Driveshaft If the driveshaft is not damaged, then just remove and replace the U-joints. These parts are subject to high stress and are way too cheap to take a chance on failure.
Inspect the yokes and transmission tailshaft. There are high-performance shafts and yokes available now that were not a few years ago. If you are looking for a little more performance, check out some of the new stuff.
Brake System Remove the brake and clutch master cylinders, flush the lines, and rebuild the cylinders. The last thing you need is brake failure, or clutch failure for that matter.
If your brake lines have been banged up or otherwise damaged, you might consider replacement while the car is apart. At least replace the flex lines, which may contain degradable synthetic hose inside the woven stainless steel.
Look over the clutch and brake pedal bushings and replace them if worn where there is excess play. Look over the brake adjuster and clean and lubricate the cable.
Seats, Belts, Window Net For safety purposes, we need to look over the seatbelts and seats. For all the reasons previously given, stress from hard racing might have damaged your seatbelt system.
Grease the U-joint cap bearings...
Grease the U-joint cap bearings while the driveshaft is off the car. Better yet, replace them. Look for dings in the driveshaft that may affect the strength and/or balance. If it looks damaged, have it repaired or replace it.
There should be no fraying or tearing of the material. The mounts must be stress free and not bent from the original location. Check the manufacturer's date on the belts. Each track and/or sanctioning body has rules governing how dated your belts can be.
Inspect your head-and-neck restraint system (you are using an H&N system, aren't you?) and your helmet. We know of one case where a hard hit damaged a helmet because the driver's head moved forward so hard that it dented and cracked the material inside the helmet. Luckily, the driver's HANS Device stopped his head from moving forward to prevent any serious injury, but the helmet was useless afterward.
Don't forget to recheck the fire suppression system to see if it will work properly when needed. The fire bottle is rarely needed, but when it is, things get urgent in a hurry.
Wiring and Switches To ensure your car doesn't stop running at the wrong moment, all wiring and switches must be fresh and free of corrosion. The vibrations that occur during a race can break or loosen the wire connections. Wiring is fairly simple, and it would make good sense to have someone rewire the entire car during the offseason.
Recheck the grommets where the wires pass through the firewall or other panels. Cycle the switches and notice if they feel tight or corroded. Replace the ones that are suspect. Many races have been lost due to a cheap switch or connector.
The foot box and pedal assemblies...
The foot box and pedal assemblies need a lot of attention in this car. A whole year's worth of dirt and grime are collected here. To prevent interfering with the brake balance and general operation of the pedals, you should remove the assemblies and clean and paint this area.
Install heavy-duty U-joints...
Install heavy-duty U-joints if you haven't already. These units take lots of abuse and hold up where stock ones will not.
Remove and inspect the seatbelts,...
Remove and inspect the seatbelts, especially the portions where they enter the seat openings. Check the date on the belts, too. Most tracks and sanctioning bodies have rules governing how old your belts can be.
Check all your wiring to detect...
Check all your wiring to detect worn or frayed wires. Where the wires pass through the firewall or other partitions are areas of concern. Replace the rubber grommets and wiring if necessary to feel comfortable that a short will not ruin a good night of racing.
Crush Panels and Overall Cockpit Sealing The driver's compartment should be isolated from the engine heat, the exhaust fumes, and fire (should the engine or fuel cell catch fire). The panels that mate to the fenders, floor, and rear deck are supposed to be sealed.
Recheck these seams and reseal if necessary. Replace bent or otherwise damaged panels. Now would be the time to add heat barrier material to the panels near the driver to reduce transient heat from the exhaust passing through to the driver.
Rear End The rear end should be removed, and all mounts cleaned and inspected. Replace all grease seals, axle bearings, and pinion bearings where necessary. Check the axle tubes for damage and to see if they are straight. Shock brackets and trailing arm brackets need to be inspected for damage or wear. All Heims should be examined and replaced if worn excessively. Don't forget to look at the third link, or lift arm, too.
Look over the Panhard bar mounting brackets to see if they are bent or cracked. These mounts take a beating, especially when small hits are experienced during a race. Not much attention is given after the race, but we can all remember incidental contact that might have caused some damage.
When replacing the fenders,...
When replacing the fenders, reseal the panels that isolate the driver from heat, carbon monoxide, and fire.
Fuel Cell After removing the fuel cell, inspect the container for rust or damage that may compromise the cell itself. The fill tube assembly and foam should be removed from the cell. Clean the inside of the cell and get rid of dirt or other foreign material.
The foam should be replaced, and the fuel pickup should be inspected and cleaned. If you have a fuel pump that pushes fuel to the engine, as some cars do, inspect the wiring and general condition of the pump.
Fuel cells have a certain life span. Some newer fuels have been known to eat at the seams under certain conditions. Inspect your cell to make sure this is not a problem. (More information on fuel cell maintenance can be found in the article entitled "Alcohol Maintenance," Feb. '07 Circle Track.)
Rollcage If the body has been removed, the rollcage can be easily inspected. Look closely at all the welds. If the car is older, inspect the inside of the tubing for corrosion, which would weaken them.
If the car is unfamiliar to you, checking the wall thickness of the tubing would be a wise idea. Some racers get carried away with weight issues and might circumvent rules that require a minimum wall thickness for rollbar material. If you find weak or thin tubing, replace it. To not do so may be considered criminal in some courtrooms.
Fender braces and other connectors...
Fender braces and other connectors should be replaced. These cheap units are usually bent and abused during the season.
Body Mounts and "Glass" The overall condition of the car's body can be evaluated during this process. Any panels, fenders, rivets, or body mounts that might have been damaged throughout the year can now be replaced. Those who race hard will have some damage to the body parts. Parts made of fiberglass will be weaker as a result. New parts offer more resistance to being "leaned on" in the coming season. Also, loose body parts can ruin your aerodynamic advantage.
If you decide to replace the whole body or parts thereof, take advantage of newer designs of nose pieces, fenders, or hoods. When replacing any of these parts, check to see if a more aerodynamic piece has been developed. Don't settle for last year's design.
The key points to remember are as follows: find any structural or mechanical problems with the chassis or components that are bolted onto the chassis; correct any safety-related problems that involve wear or age of the seatbelts, restraints, fire-suppression system, helmet or seat; and make sure the driver's compartment is sealed properly against heat, carbon dioxide, and fire intrusion.
After each season, go over your race car during the winter months so that when you hit the track again in the spring, it will be just like a new car. You can avoid failures that may have dire consequences if you do this job the right way. And anyway, getting there is more than half the fun.
This panel in the rear of...
This panel in the rear of the car was cut to fit around a piece of tubing. The cut was too large to fit closely and was never filled in. If the fuel cell were to burst, this is where fuel could possibly enter the driver's compartment. It doesn't take much to cause a lot of problems.
Go through the rearend and...
Go through the rearend and replace bearings, seals, locker spring, and so on. Some differentials are more high-maintenance than others. This kind of maintenance should be done more than once a year.
Inspect all the rollbar joints...
Inspect all the rollbar joints for broken welds or other types of fatigue. Pay close attention to where the rollbars attach to the framerails and where trailing arms and rear shocks are connected.