When people reflect on the heritage of the WRX, they credit the Liberty RS turbo a proud parent, but they often forget the little-known Grandfather, the Subaru RX Turbo sedan. The RX sedan was the first all-wheel-drive 1.8-litre boxer 4-cylinder turbo sedan to hit Subaru's showroom floor, arriving in the late 80's.
Sydney's Marcellus Loh saw a pristine RX Turbo in a dealership - complete with logbooks - in March 1999. $4250 later he was the third owner of this 1987 RX Turbo. The RX weighing in at only 1070 kilos came with a whole stack of goodies in stock form, an EA82T MPFI (multipoint fuel injection) twin cam 1800cc with 88kW, rear LSD, IRS, four wheel disc brakes, heavy-duty suspension and some really huge RX Turbo stickers splashed up the sides and on the rear bootlid. For reasons unknown, the Subaru designers went crazy with the chequered flag theme. Inside, all the seats have chequered flag trim and even the seat belts are in black and white chequered print to continue the theme!
Marcellus was looking to build a sleeper, sort of a Dr Jekyll and Mr Hyde with the biggest possible motor and the smallest possible car with maximum traction. The Granny-pack RX turbo fitted the mould perfectly. From the outside, nothing but 80's styling and with huge(?) 185/65/13 factory rubber on the front and rear. But nowadays once the 'go fast pedal' hits the floor, there's nothing but adrenalin pumping, brown undies acceleration!
The first things to go were the huge RX Turbo stickers ("which gave it at least an extra 5KW, ha ha") The next course of action was a trip down to a few local workshops to get prices for a front-mount intercooler, air filter and a larger exhaust, but Marcellus was told, "fitting a large intercooler can't be done!" Marcellus soon realised it was going to cost big bucks and then how much more power was the 1.8-litre going to reliably make, as no one had ever built or worked on these motors?
The next day Marcellus went around to a friend, Wayne to show him the car and explain his performance predicament. Wayne listened patiently and he said, "I've got one word to say to you to solve your problems - and that's EJ20T." With that, Marcellus was off to the engine importers with a trusty measuring tape in hand to see if the EJ20T would fit. Sure enough the EJ20T just slotted in. After shopping around all he could find were half cuts with an auto box. So $1800 later he was the owner of a Liberty RS turbo half cut, with the importer's assurance that the gearbox would bolt straight on. Once the half cut was at home, it was time to blow the EA82T anchor, so the actuator hose was disconnected from the turbo and some fun was had for a few days until the engine finally blew. During this time numerous enquires were made to many workshops and they said the same thing to Marcellus - "it couldn't be done" and "I was stupid". These words were like throwing petrol on a fire, so the conversion started in the family garage, just one week after buying the car.
A Liberty turbo gearbox was sourced from Queensland via Brookvale spares. Marcellus is tight-lipped about the fine details of the conversion, as no workshops were willing to offer any advice. So he isn't quite ready to explain to these people the complete conversion, but the following information will head you in the right direction. As with many engine transplants, the gearbox and engine mounts had to be remanufactured. In short all the mounts are WRX mounts. The engine mounts required a small amount of welding and machining. The gearbox mount was completed on the third attempt and didn't require any welding, "just a little cut and tuck". The EJ20T gearbox linkages required a new bracket and the transmission tunnel was persuaded a little wider courtesy of Marcellus' hammer. As the gearbox sat further back, a new gear stick hole was made in the floor and a new shortened tail shaft was needed. A slightly heavier duty clutch was also installed. Twin thermo fans were added in front of the radiator to blow air through the single core radiator - this standard radiator was to become a problem down the track. The standard IHI RHB5 VF14 turbocharger was retained, with the plan to replace this when there's a bit more brass in the piggy bank. And to finish it off, the spare wheel (normally mounted under the bonnet) was given the flick to create space for the turbo plumbing.
Marcellus never thought he was going to get this thing on the road and nearly gave up several times, but somehow he completed the mechanicals. After three months on weekends of blood, sweat and beers and sometimes punch-ups with his brother Alex, the EJ20T was installed and ready for the auto electrician.
Next the RX was off to the auto electrician to fit the standard computer and uncut loom. It sat at the auto electrician for a month and all that happened was the loom was taken out of the half cut. The auto electrician was unable to do the job so everything was thrown into a car trailer and towed home using Marcellus' trusty 1973 TA22 Celica ("it nearly killed it!"). After a quick inventory check at home, it was discovered that the auto electrician had cut the wiring loom in half! So Marcellus repaired the loom and sent it to another auto electrician where it sat there for nine months with nothing being done at all.
By this time Marcellus was ready to give up and sell the car, but he wanted a return for all the effort he'd put into the RX. So he decided against fitting the standard computer, as installing an aftermarket ECU would make it easier to fit, tune and reprogram as the modifications changed. Croydon Autosports was put in charge of wiring the MicroTech MT8, a task that took 6 weeks.
The exhaust system was up next for an overhaul, with a three-inch dump pipe starting at the back of the standard Liberty RS turbo to a hi-flow cat, into a three-inch system to the tip. With the MicroTech fitted, it was time for tuning. On the dyno, with boost at 13 psi running through the standard RS water to air intercooler. A mild (for a constant four-wheel drive!) 112kW was recorded at all four wheels. On the road, lack of traction made the car a bit of a handful. Stall it up, dump the clutch and the tyres would spin all the way through first and half the way through second gears! So the rear tyres were changed for 205/60/13 and the front tyres stay the same with 185/65/13. Why 13-inch rims? "It's got to be a sleeper!"
Happy that the car was finally on the road, the search for more horses was found with more boost and filter. The standard air filter was tossed for a conical K & N and some stainless steel 3-inch pipe work fitted. The boost was wound up to 16psi, but the standard water to air intercooler was at its limit with air temps getting to 65 degrees plus. Marcellus paid a visit to his local radiator dealer, who fitted the front mount intercooler and RBR blow off valve. Marcellus also fitted some water sprayers for the intercooler. Then it was off back see Jim at Croydon Autosports who dyno'd it on 16psi, with the result 130kW at all four wheels.
As mentioned earlier, the standard single core radiator now became a problem, as the air travelling through the radiator was getting the second hand air that had just travelled through the intercooler. At this point the fans were reversed so they were now sucking air through the radiator, but it made no difference, as it was still second hand air! Water temperatures were getting very hot. So it was back to the local radiator dealer, where a custom-made aluminium twin core 2-inch thick radiator was fitted.
With the water temperature now behaving itself, it was time to hit the track. Down at the local Eastern Creek street meet Marcellus was able to record a time of 13.45 seconds. Not bad considering the car was driven in street trim and the standard turbo was boosted to only 16 psi!
We look forward to future developments, from Marcellus' RX 'Grandpa' car....
Thanks to: Marcellus's parents and brothers Alex & Benjamin for the use of the garage and not giving too much grief about the state it was in and still is now! Also mates Wayne & Damian
No thanks to everyone who said it couldn't be done!
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