RACE CAR TIPS/ADVICE
Stole it from another forum, but certainly a good read and some good advice.
The failure of engine peripherals is the most common cause of DNF's in Club Car racing. Here is a few ways of improving reliability.
Alternators. A standard alternator is geared so that it will charge as you dawdle around town at 2000 rpm engine speed. When you put a road car alternator in a race car being revved to 6000 rpm +, the alternator is being spun at revs much higher that it was designed for, and consequently doesn't live long. Gear the alternator down, by installing a larger pulley (typically 4" minimum) on the alternator, or on a rotary, a smaller crank pulley. Loc-Tite or safety wire the mounting bolts, they have a tendency to work loose. Install a volt gauge which you check at the end of each session. It should read between 14 and 16 volts at anything over 4000 RPM. Any reading outside this range indicates a problem. Watch for regular alternator failures due to vibration - it could indicate a problem with the crank damper, particularly on a four cylinder. A broken crankshaft can be a dead give-away.
Battery: Put your battery on trickle charge the night before a race meeting. A battery will discharge sitting around for a month at a time, particularly if it is not in perfect condition. Battery isolation switches are now mandatory, and are a good idea anyway. They make working on the electrical system much safer, and are more convenient than manually disconnecting the battery. They are also a good safety feature in the event of an accident. Install the switch so that the driver can reach it when strapped in.
Distributor leads : Check regularly for resistance. Suppression leads should be between 1500 & 3000 ohms for suppression leads, less for race leads. If you run electronic injection, use suppression leads, and don't route the wires for the crank angle sensor around the distributor or near the leads. The voltage can interfere with the signal. If leads tend to work loose on the distributor cap, cable-tie them around the terminals. Don't cable tie leads together, they will cross fire - keep them separated.
Ignition: Run a separate switch to the ignition coil, not through your 25 year old ignition switch.
Throttle cable - This would be the all time most common failure on a Club Car. It is also the most preventable. Solder or crimp cable ends, and check regularly for fraying. Don't use clamp on type fittings. If you need to replace an inner, boat shops carry a suitable cable with a 200kg + breaking strain.
Fuel system : Under high cornering loads, fuel pickups can suck air, at best causing engine hesitation, at worst leaning out and detonating the engine. The cure is to fit a surge tank, either gravity or auxiliary pump fed. Carrying around a full tank of fuel is the unsatisfactory and arguably dangerous alternative. If the surge tank is gravity fed, make sure the top of the surge tank is below the bottom of the main tank, and fed with at least a 1/2 inch line, and preferably two. No, the surge tank does not have to be tall and skinny. If you have a return line, run it into the surge tank, with an overflow back to the main tank.. About one litre is big enough. The pickups should be at the rear and bottom of both tanks, so when you are running dry, the pickups will get fed under acceleration as you exit a corner. If you race a Datsun 1600 with an original fuel tank, buy yourself a new fuel cap. Your 25 year old one will spew fuel around left handers, and is a sitter for a black flag, as well as being uneconomical, and dangerous. Route the fuel lines where they won't absorb heat & get vapour lock. A sight gauge is a good idea, because relying on an old fuel gauge is a good way to run out of fuel in a race. Use a fuel injection filter in an injected car, and a carby filter in a carby car, not vice versa. Carby filters in injected cars explode and injection filters designed for high fuel pressure restrict the fuel flow unnecessarily in carby cars. In a carby car, use a good solid metal or glass filter. The cheap plastic ones have been known to crack, and some of them don't like avgas.
Oil system : Safety wire oil filter on using a large hose clamp around the oil filter, particularly if you have a Gemini twin cam. Fit a baffled sump, almost all standard road car sumps will surge on a race track, and the pickup will suck air, which can be potentially disastrous. Don't overfill the sump, the crank will cavitate the oil, resulting in low oil pressure and lost horsepower. Fit a big red oil pressure warning light somewhere easy to see, with a sender which comes on at 35 PSI. Standard road car senders come on at 5psi, just in time to tell you your engine is history. Standard or mild engines piston engines probably won't need an oil cooler, rotaries will. Any race spec engine will. Mount the oil cooler in airflow, buy the biggest one possible, don't mount it hard up against a solid surface, and don't mount it outside the coachwork (illegal). You cannot cut holes in the bodywork to duct air, and you cannot remove headlights. In front of the radiator works well on later model cars, behind headlights or behind front spoilers on early model cars with less room in the engine bay. You can cut holes, for example in the radiator support panel, to route oil lines. If your sump protrudes below the crossmember, fit a sump guard, it will give you some confidence when kerb hopping.
Cooling system : There are a number of things which can be done to improve your cooling system, without changing the radiator. Removing the thermostat is not one of them. A correctly working thermostat will slow the water speed through the radiator, giving it time to cool, as well as holding the cool water against the block longer for better heat transfer. Gear down the water pump, and put in a restrictor, if you feel you must remove the thermostat. Seal between the radiator and the support panel. Air will always follow the path of least resistance, and if there is a gap around the radiator, it will flow through the gap instead of the radiator. A front spoiler will create a low pressure area behind itself and the radiator, often improving airflow and therefore cooling. Watch the water pump speed, particularly on a 6 cylinder Holden. Some pumps can over rev and cavitate. Adjust the pulley size if necessary. Change your radiator hoses and fan belts every two years. If you have a mega horsepower engine, be aware that if the cold air intake draws from in front of the radiator, it can partially starve the radiator. A higher pressure radiator cap will raise the boiling point of the coolant, as will the addition of antifreeze/boil. These products also act as a corrosion inhibitor, which is not a bad idea, remembering that heat accelerates corrosion. The radiator cap should be the highest point of the cooling system, to prevent air locks. The overflow pipe should go into a catch bottle, so when the engine cools, the overflow is drawn back into the radiator. This saves you topping the thing up after every race, as well as keeping vital bits of your electrical system (eg distributor) dry.
Starter motors: How many times do you see cars being push started on the dummy grid? Solenoids on race car starter motors are prone to heat soaking and jamming, so insulate yours. Nissan FJ20 reduction gear starters are nice, and can be used on Datsun L series motors as well. Loc-Tite or safety wire the mounting bolts. Don't run your starter through the ignition switch, particularly on an old car, as you usually get a voltage drop. Use a marine starter button with suitable amperage cable direct off the battery, and on the engine side of the battery isolation switch..
Exhaust: Chains are the preferred method of attaching a race car exhaust. Don't mount the muffler too low or you will rip it off on a kerb or getting it off the trailer. Attach the entire system so that if one chain fails, the other(s) can support it. A dragging exhaust equals a guaranteed black flag. Unless your engine is solid mounted, allow the exhaust system some movement or you are asking for a set of busted extractors.
Clutch: A solid centre button clutch is preferable, even on a standard or "wrecker" motor. It represents cheap drive train reliability. Don't even think about using a sprung centre fabric clutch on a race spec motor. Drill a small hole in the bell housing so you can monitor clutch wear. Use drill bits to estimate the thickness of the remaining friction material, and stick to the manufacturers recommended minimum thickness. If you have a cable operated clutch, check the cable regularly for fraying. If you have a hydraulic clutch, monitor the fluid level. If it drops at all, check behind the dust boots on the back of the master and slave cylinders to see where it is leaking, and rectify. Properly maintained hydraulic cylinders rarely "blow" without warning, they will usually start with a small leak, and if not fixed, they will then blow, usually when you are on your way to the dummy grid for the first race.
Exterior engine checks: A regular leak down test or compression test is a good way of monitoring ring wear and valve condition, and if done regularly, will give you an idea of how often the motor needs to be rebuilt. It can also help prevent nasty surprises the next time you go to load the car on the trailer. Keep an eye on your engine mount condition, and if cracks appear, replace them. If left unattended, the mounts will one day break clean through, most likely at the start of a race. Check around the welsh plugs for any sign of leaks, and replace them whenever the motor is apart.
Strategies for improving your lap times.
Practice makes perfect. A very experienced former professional racer once said to me, "the problem with you blokes (referring collectively to amateur racers), is that you are ready to go racing at about four o'clock Sunday afternoon." He was referring to the general lack of testing and practice undertaken by Club Car racers. Unfortunately, we don't all have mega dollar budgets, so we have to be careful about how we spend what budget we have. Racing and practice miles is about the most economical way to improve your lap times when you are starting out. New racers often find that they get quicker as the day progresses, setting a better lap time in their final race than in qualifying. This is because of the experience and the increased confidence on the circuit. Practice the day before will help you to set a quicker time in qualifying. A quicker qualifying time will improve your position in the race. It doesn't take much - I've seen days where four tenths of a second could move you six spots up the grid.