BASIC DETAILS

The engine currently being used in the PREDATOR RACING FUNNYBIKE was originally A 1984 suzuki GSX1135 EF.

An In-line 4 cylinder air-cooled motor with 4 valves per cylinder.

It was a sports/tourer bike that came available with or without a fairing.

It developed approximately 120 BHP and could approach 140mph. It has always been a favourite amongst Drag racers due to its very efficient cylinder head and extremely strong bottom end

TOP END

Standard suzuki EF cylinder head featuring TSCC (Twin Swirl Combustion Chambers) with 28mm inlet valves and 23mm exhaust valves, standard twin overhead camshafts indexed to our own settings.

The original barrels have been replaced by an MRE big block assembly, which houses 84mm pistons (4mm oversize) giving an engine capacity of 1428cc,

The pistons are held on the connecting rods using 18mm wrist/gudgeon pins and these are held captive by Teflon buttons at either end.

BOTTOM END

Standard suzuki EF crank shaft – indexed, and fitted with a straight cut primary gear by Dave Branch Engineering The small end of the connecting rod is bushed down from 20mm to 18mm, to allow the bushes to be replaced if required.

TRANSMISSION

This bike uses a semi automatic 3-speed gearbox. It provides a near seamless transition from one gear to the next by engaging the following gear whilst still driving through the existing gear until such a time as the next gear accelerates the output shaft up to a speed when the preceding gear disengages centrifugally.

The down side to this is that the rider cannot close the throttle in first or second gears as this will cause the two gears to be forced toward each other thus bending the selector shafts – requiring their replacement.

This takes approximately 90mins and is a job that our team is well practiced at J

The gears have to be changed by an input by the rider (i.e. no fully automatic transmissions are allowed) ours is shifted using a pneumatic ram activated by a button on the handlebar. This system uses dry nitrogen, which is stored in the chassis at up to 125 psi

INDUCTION AND FUEL SYSTEM

We favour the “forced induction” route, We use a Garret T3 / T4 hybrid turbocharger (assembled and tested by TURBONETICS of California) that sucks air through a single 55mm S&S carburettor – drawing up fuel as it passes over the 2mm main jet. This high pressure (28psi) fuel/air mix is forced into a plenum chamber where it waits (briefly) for the intake valve to open.

The carburettor is kept topped up with fuel fed through a 10mm diameter pipe by air pressure (the fuel tank is pressurised)

We also employ nitrous oxide injection for added power, although we are actually using very little because of the efficiency of our Turbocharger.

IGNITION SYSTEM

The ignition is provided by a Dyna 4000 electronic ignition unit and set at a fixed 28 degree advance.

It is fired by a magnetic trigger on the right hand side of the crankshaft (the other end is used to drive an alternator thru a toothed belt).

The main ignition box also provides connections for an RPM reading device such as a shift light and allows us to use two pre-set rev limits (one for the launch and one for maximum engine revs).

For 2003 we hope to have a ten channel on board computer fitted to record data from every pass down the track.

Our estimated horsepower at present is approximately 400 bhp (including 60bhp provided by nitrous oxide)

Predator Racing 2006
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