consider the 250cc F/E's or the "big
twins" as the holy grail of karts!
This, the "Big Kahuna" category of karts,
derives its "Twins" nickname from the use of two cylinder 250cc Grand
Prix motorcycle engines such as Honda, Yamaha and Aprillia or purpose made
Rotax, SGM, Hemmingway, FP, BRC and Vee-Dot superkart engines. All modifications
are allowed to the engines allowing them to produce around 90 bhp.
a combined kart/driver package weight of 220 kg adds up to a machine capable
of speeds well in excess of 240 kph on faster tracks and lap times that
cheerfully embarrass teams in other categories of motorsport with racing
budgets exceeding many hundreds of thousands or even millions of dollars per
250cc Inters lap Phillip Island GP circuit (Victoria) significantly faster
than 600 + bhp V8 Supercars costing hundreds of thousands of dollars to
purchase and still more to maintain!!!
All this in
a package that can fit into a box trailer!
250cc F/E karts can be no more technically complicated than 250cc IC/E or even a 125cc machine, however, they do require careful tuning,
really thorough preparation and regular
detailed maintenance to perform reliably at anywhere near their peak.
The list of
go-fast goodies available for these machines is almost endless, such as real-time data acquisition, carbon
fibre and kevlar components such as wings, fairings, seats and bodywork
as well as magnesium and titanium bits and pieces. Rack & pinion steering
boxes, air operated gearshifters, fully floating brake discs, multi-piston brake callipers with on
board bias control and on to trick programmable engine ignition systems,
purpose made expansion chambers (exhaust pipes) to suit different tracks
and perhaps a big wooden box full of different gearbox ratios and drive sprockets
plus a couple of spare factory modified cylinders and maybe a spare crankshaft
assembly thrown in to impress your friends with!
needs to be said that most of these exotic goodies are only really necessary at the
very highest level of the sport. This type of technology comes at a premium
price and it is totally up to the individual to decide if the performance edge
(if any) gained is worth the investment.
motor cycle engines, although rather highly developed, are surprisingly
reliable when fitted to a superkart and will put in many kilometers of
racing before significant component replacement or worse, component failure
becomes an issue. Don't be fooled by GP motor cycle engines' apparent simple design and
outward appearance. Those aluminium castings disguise
thousands of hours and many millions of dollars in design and development. These
engines can produce over 350 bhp/litre at
their best but can be quite pedantic by nature and require careful tuning to
perform well. The difference between a successful days racing and a costly
engine failure can be no more than a couple of jet sizes, wrong sparkplug choice
or a careless ignition timing
are definitely not a beginners kart and best suit those of you with a good
degree of technical knowledge and higher degree of driving ability.
Reasonable entry level
250cc F/E's can be had for as little as $6000 and over $30000 if you want
to look real flashy, go real fast and guarantee a crowd of tyre kickers
surrounding your expensive toy in the pits!
These karts can be identified by Black racing numbers on a