2026 Q1 Review - Hatchback

We originally planned to sell the closed deck EJ20 2.1 stroker engine that we assembled in late 2025 and run in using the hatchback. However, with no buyers for the 2.1, it was decided to keep and develop the engine as a showcase for Pleiades Performance at car shows and time trial events. It was then time to purchase some upgrades during the winter sales! First on the list was a high quality exhaust manifold. We have been very pleased with the build quality, fitment, and performance afforded by the Killer B equal length stainless steel exhaust manifold on the hillclimb car, another one was purchased for the hatchback (although we are sad that the characterful Subaru rumble will no longer be present). Next, a high quality modern turbocharger was on the list. As ever, our go to turbos are those sold by AET Turbos in Normanton, specifically the Xona Rotor models. Due to the impressive boost response and power band provided by the Xona Rotor 6564s fitted to the hillclimb car, we decided to purchase another of these units to trial with the 2.1. Due to the hatchback's smaller displacement engine (compared to the hillclimb car) we opted for a smaller Area/Radius ratio turbine housing of 0.60 instead of the hillclimb car's 0.80 ratio turbine housing.

It was also decided to use a Bosch combined temperature and pressure sensor and a relocation kit to move our existing coolant pressure sensor to the engine coolant crossover pipe instead of using an adapter fitted to the top radiator hose. This eliminates using jubilee clips on the silicone pipes, and makes the engine bay wiring a tiny bit neater! A Deatchwerks 620R fuel pump and fitting kit was ordered to provide plenty of fuel once the boost was increased, along with a Fluidampr crank pulley to dampen any increases in crankshaft vibration. To top it off, a set of Samco silicone radiator hoses, RCM alloy exhaust pulleys, RCM gen 3 cambelt tensioner, a set of Cosworth plastic TGV deletes, and a black Process West reverse intake manifold completed the modifications order. Buying the parts, however, was the easy bit! It was then time for the fitting to commence. The first job was to check the valve clearances in the 2.1 whilst the engine was on the stand. Having made some minor adjustments to the existing clearances, the RCM alloy exhaust pulleys and the RCM cambelt tensioner were installed - the increased tension in the timing belt was noticeable compared to the standard tensioner setup!

Next, a Killer B water pump housing was installed (which we also have on the hillclimb car), and then it was time for the Killer B super G sump. This took a little while longer to fit than expected as a baffle was fouling against a casting on the engine block (no fault of Killer Bs as the sump is not listed as fitting the older EJ20 engines), which was alleviated with some careful filing.

During the running in period, the way in which the turbo oil pressure regulator was mounted caused a small oil leak (see the picture).

To rectify this, we contacted the experts at Racinglines in Nuneaton for their advice. They quickly added in a short length of braided stainless steel line from the engine feed banjo bolt to the T-piece connector, such that engine vibration would not be transmitted to the T-piece, which caused it to slowly loosen whilst driving.

It was then time to test fit the Killer B exhaust headers and to fabricate the "DIY" turbo up-pipe provided by Killer B to locate the Xona Rotor 6564s. Handily, it was possible to copy the hillclimb car's up pipe to get the hatchback's turbo in position. Having initially copied the up-pipe by eye, we needed someone to finish the up-pipe and weld the v-band clamps in the exact positions.

ProFab exhausts in Swansea were again to our rescue and the expertly crafted up pipe was installed. Having installed the engine in the car, the engine ancillaries could then be fitted. These included the new coolant combined temperature and pressure sensor, and the Process West intake manifold.

At this point, a slight diversion was had in the form on refreshing the alternator by vapour blasting the aluminium casings by the brilliant DC Customs in Caerphilly, installing two new bearings, and a black aluminium pulley.

Due to the new intake manifold position, the air conditioning compressor could not be used (which we might regret during the summer months), and the alternator needed to be relocated. Handily, alternator relocation kits available from various companies, with some parts from the Fuji Racing alternator relocation kit installed on the hillclimb car. For the hatchback, the IAG V2 alternator kit was installed, which was generally easy to fit, but was tight on the DBW throttle body's connector, required bending the oil dipstick to clear the bracket, and using a different aux belt to that supplied in the kit. The next task was to fit the Turbosmart Gen V Powergate 60mm external wastegate supplied by AET Turbos to the exhaust manifold. This necessitated cutting and TIG welding a short joiner pipe to the gate, TIG welding the v-band clamp to the pipe, and fitting a short dump pipe to the wastegate exit port.

We can't wait to hear what this sounds like once the boost is turned up! We have plenty more work to get the hatchback back on the road, with fabricating a joiner pipe from the turbo to the downpipe, and connecting the ancillaries in the engine bay next on the list! Stay tuned for the hatchback's Q2 update for 2026.