Class 1 Standard 1000cc Mini's. As with all
Autograss cars they have the trim, dashboard and seats removed.
The engine is standard with very little modification allowed.
The only engine capacity allowed is 998cc, in either the A
series or A+ types. A roll cage is installed and fire
extinguisher fitted, within easy reach of the driver. Juniors,
ages 12 - 16, are allowed to drive class 1 cars in separate
races. This class was previously restricted to Minis, but the
Fiat Cinquecento and Citroën AX have been added to the list of
eligible cars recently.
Class 2 is open to front or rear wheel drive cars up to 1300cc.
The engine can be either front or rear, and both are popular.
Cars seen most regularly in this class are Mk2 Escorts and Skoda
Estelles. Since the introduction of front wheel drive cars into
this class the Vauxhall Nova has become one of the favourites.
Only 2 valve/cylinder cars are allowed and there is a minimum
length requirement, preventing use of 1275cc Minis. The inlet
tract is fitted with a restrictor, to even out performance
amongst the vast collection of vehicles used.
Class 3 is the first of the unlimited
capacity classes. Unlimited modifications and unlimited capacity
are allowed; the only restrictions are a maximum of 2 valves per
cylinder and front engine, rear wheel drive. This leads to very
powerful cars with little weight over the driving wheels, and
very sideways action.
Class 4 is a modified class, with engine
capacities allowed up to 1130cc. Any engine modification is
allowed, except turbo and super charging. This is a class not
for the shallow of pocket; engines are extensively modified to
bring them to a competitive level, as a specific of the rules is
that the original engine and position are retained.
Class 5 is a very popular starting point
for people wanting to drive modified saloons. Engine capacities
from 1131 to 1420cc are allowed, the engine does not have to be
the original or in the original position. A lot of cars run rear
engines to help improve grip.
Class 6 is for cars with unlimited
engine capacity and modifications in a front engine/front wheel
drive combination. Costs to compete at the top level can be
high.
Class 7 is restricted to rear wheel
drive cars. The engines are unlimited, but must be above 1421cc,
or 1000cc if a bike engine. Even two engines may be run, as is
the case with the bike engined cars. Quite often large amounts
of money are spent on the engines for these cars, including
Cosworth turbo motors, large block American V8s, and V6s of
different types, all highly tuned. The sound of this class
thundering down the straight is enough to make some fans go weak
at the knees.
Class 8 is the most competitive of the
special classes and is also the one with the lowest engine
capacity limit, a maximum of 1420cc. In the vast majority of
cars bike engines are used, even though they infrequently reach
the engine capacity limit of 1350cc. Engines may be tuned, but
as usual with capacity-limited classes may not be turbo or super
charged. All cars are mid-engined; this is not part of the
regulations, but is the best way to get the most weight over the
wheels. With the large grids this class attracts it is one of
the best to watch.
Class 9 is the class most likely to win
an open-class race. This class combines the high power output of
the modern 2.0 litre engine with the lightness to allow better
handling than the heavier class 10 vehicles. The capacity limits
are between 1421cc and 2070cc and any modifications are allowed,
with the usual exception of turbo and supercharging. All cars
are mid-engined with most utilising a transverse gearbox layout
and rear wheel drive.
Class 10 is one of the most powerful
classes around. Another of the purpose built classes, this one
has a minimum capacity of 2071cc but no upper capacity limit or
limit on the modifications made to the engine. Twin bike engines
are popular with the capacity limits being between 1550cc and
4000cc, as is V8 power. Once again all cars in this class are
mid-engined, again for no other reason than that it seems to be
the best solution. Phenomenal amounts of money can be spent to
gain competitiveness in this class, with fully-built cars
costing more than some small houses.