At Beek Auto Racing, after finalising the full 4.3 'S' spec with the 123tune fully mappable ignition distributor by 123ignition.
Full engine spec:
4.3 litre, standard sized valve (39.8/34.6 mm) engine with big journal crank, fully balanced and tuftrided
Lightened and balanced rotating assembly incl. flywheel
Ported heads, new valves and valve train components, bespoke Piper cam
ARP rod bolts and head studs
45 mm ported intake manifold
ACT 45 mm carbon superflare trumpets; thermal trumpet base gasket
ACT carbon twin throttle plenum and intake hoses
Huge Bosch airflow meter (BMW 4.4-4.8l V8); Siemens 'Vectra' injectors
ACT stainless performance exhaust manifolds + decat pipes
123tune USB programmable ignition
Magnecore ignition leads
Result - 300 hp @ 6000 rpm or 50-60 hp over a standard 4.3 engine - with excellent driveability at all rpm and load levels, superb response and a very wide power band (2000-6000 rpm). Also, the lightened internals and carbon plenum have reduced the weight by about 15 kg...
The red line is the result of the run with the mapped 123tune ignition (5000-6000 rpm) - +26 hp maximum, + 40 hp at 6000 rpm!