Preparing for Speed Events
By Don Woods
A speed event is held on a closed
circuit, sealed or unsealed, and can be a hillclimb, quarter mile drag,
regularity or circuit sprint. A full description of these types of events can be
found in the MG Car Club Handbook, commonly known as "The Blue
Book". Descriptions of the major events, including speed events, can
be found here.
In preparing for these events,
various components must be considered, some that are compulsory and some that
are optional (but generally intended to make you more competitive and confident
that your vehicle is in the best possible condition).
So let us consider these various
components.
Vehicle
A vehicle should be clean and
tidy without any loose objects in or around it. All unnecessary objects should
be removed and those that are required must be rigidly and solidly attached. All
lights, particularly the brake lights, must be in working order.
A fire extinguisher must be
fitted and rigidly attached (no wire, cord, rope or plastic holders) and must be
able to be reached by the driver while in his seat. It should not be within the
drivers’ side of the cockpit.
For vehicles with rear-hinged
bonnets, a second independent restraint system is required. This can be as
simple as a piece of cord that will hold the bonnet shut if the primary lock
fails.
Ensure that your seat is firmly
fixed and provides support. Seat belts of at least the lap-sash type are
required.
Wheels and Tyres
All spokes should be tested for
tightness and the wheels spun for out-of-round or buckling. On the standard wire
wheel width rims (41/2"), 185x60x14 tyres can be
fitted that will improve the performance and handling of the car dramatically.
The handling can be further
fine-tuned by adjusting the tyre pressures. It is usual to provide a
differential front to back of anything from 2 – 5 psi. The actual tyre
pressures depend on a number of factors such as wet or dry track, asphalt or
dirt surface and the type of event. A good starting point for a dry track is
45/40-psi front/rear.
The wheel knock-ons should be
tightened and checked again just before competing.
Suspension and Steering
All suspension components, arms,
bushes, pins, tie rods, steering rack, shock absorber mounts and links,
anti-roll bar mounts and links should all be checked and tightened as necessary.
Fitting a larger diameter anti-roll bar (approximately 5/8"
dia.) will assist in reducing rear wheel lifting under hard cornering.
The steering wheel should have
nearly zero free play and be tight on the steering column. Make sure that the
steering wheel nut is tight.
Brakes
The brake fluid should be bled or
replaced. It may be an advantage to fit harder brake pads. "Metal
King" type will still give enough bite around town and will resist fading
much better than standard pads under hard use. Ensure that the rear brakes are
not binding and do not have excessive free movement. The brake pedal should be
hard with minimal movement.
Engine
The engine should be thoroughly
checked to ensure that it is performing at its optimum level. All aspects that
control the performance should be checked, cleaned, adjusted and reset. So let’s
start.
The simple things like oil and
water levels must be correct and, if they haven’t been changed for a while,
drained and refilled.
Spark plugs should be removed,
cleaned (possibly replaced) and the correct gaps set (0.28-0.32 in.). The
contact points also should be cleaned or replaced and set to 0.16 in. or 560
–600 dwell. While the plugs are out, take the opportunity to check
and reset the tappet clearances, 0.15 in. cold. After the contact points have
been set to the correct gap, the distributor can then be timed to provide 100
– 140 advance. The actual advance that is best for any particular
engine depends on a number of factors that vary from engine to engine and from
specification to specification, but the above settings should be a good starting
point.
The carburetors need to be
balanced and synchronized. Balancing ensures that each carburetor is drawing the
same amount of air. To balance the carburetors, slacken off the linking throttle
rod, remove the air cleaners and, while the engine is idling at normal operating
temperature, listen through a piece of tube to the amount of hiss coming from
each one. The hiss should be the same and can be changed by adjusting the
throttle idle screws. When the hiss is the same, the throttle linkage can be
tightened, ensuring that both throttles start opening at the same time
(synchronized). There must be three return springs on the carburetors, one on
each carburetor throttle and one on the throttle cable. Refit the air cleaners,
top up, if necessary, the dashpots with the correct viscosity oil and ensure
that the fuel mixture does not create any hesitation upon acceleration. Ensure
that all the nuts, bolts and screws are tight and that the fuel hoses are in
good condition.
Driver
The driver is also an integral
part of the performance package. They must be fit and know what their car will
do under different circumstances and, also, what they can do with the car to
make it perform to its full potential. I don’t think any of us ever reach this
full potential because we usually do not spend enough time in the car exploring
limits and techniques. The driver must also think about what they are about to
do and how to go about it, plan the event and your part in it. We should
participate in as many and varied events as possible, we are all learning at
times.
MOST OF ALL ENJOY YOUR
PARTICIPATION