P... Lotusbits has also developed a fuel injection kit, providing obvious
benefits in terms o� tuneabilit�, driveability, fuel economy and refinement, compared with carbs. Initially proven on the Excel, it has also been used to good effect on the Lotusbits Micra rally car and both current Lotus Sunbeam rally cars, as well as many other customers’ road and race cars since. The kit comprises a DTA S40 engine management system and harness, Jenvey throttle bodies, injectors and fuel rail, pressure regulator, �uel pump and filter, cranksha�t sensor( including mounting bracket), crankshaft trigger disc, coolant and air temperature sensor and wheel sensor etc.... P
LEFT: The Lotusbits fuel-injection conversion has been successfully tried and tested on the team’ s own rally cars.
ENGINE UPGRADES
Initially use the Lotus parts bin to upgrade to the Lotus 912 HC spec( 180 hp). After this:
STEP 1: Upgrade standard HC engine to 2.2 litre HC spec plus CNC ported head and inlet manifold, + 1mm inlet valves, L14 cams, oil restrictor to head, balanced bottom end.
Gives 200 to 220 hp, depending on induction and exhaust system, with peak power between 6700 and 7300 rpm and a rev limit at 7700 rpm.
This is aimed at fast road use, or clubman competition cars with �urther modifications to the sump and oil s�stem.
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STEP 2: 2.2 litre, as per Step 1 plus ultra-light 13:1 compression pistons, lightweight steel rods, uprated valve springs, high-li�t cams, steel �ollowers, ba�fled sump.
Gives 220 to 240 hp, depending on induction and exhaust system, with peak power around 8000 rpm and a rev limit at 8500 rpm. This is aimed at competition cars.
STEP 2A: As per Step 2, but using Lotusbits billet steel crankshaft and billet steel ultra high-lift cams
Gives 240 to 260 hp, rev limited at 9000 rpm. For competition use.
STEP 2B: As per Step 2A, but using Lotusbits machined from solid cylinder head.
Gives 260 to 280 hp, rev limited at 9000 rpm. For serious competition use.
STEP 3: Road / trackday engine 2.5 litre, with custom long-stroke steel crank and rods, with custom pistons to match. Gives 250 to 270 hp, with peak power between 7000 and 7500 rpm. This is a detuned version of the current Lotus Sunbeam competition for road / trackday use.
STEP 3A: High-torque road engine 2.5 litre, with custom long-stroke steel crank and rods, with custom pistons to match.
Gives 240 to 250 hp and 215 to 220 lb. ft. torque, with a flat cur�e, high tor�ue �rom idle, ideal �or road use.
STEP 4: 2.5 litre, with custom long-stroke steel crank and rods, with custom pistons to match, utilising Lotusbits developed billet camshafts. Gives 280 to 290 hp, with peak power between 7500 and 8000 rpm and rev limited at 8200 rpm. For competition, as used in both Lotusbits Lotus Sunbeam rally cars.
STEP 4A: The ultimate competition engine 2.6 litre, as step 4, with larger custom pistons and liners to increase the capacity, mated to Lotusbits new machined from solid cylinder head, Gives 310 to 340 hp, with peak power between 7500 and 8000 rpm and rev limited at 8400 rpm. For competition, as used in Mike’ s Lotus Sunbeam rally car for this 2019 / 2020 season.