Video: XR6T Turbo Upgrade

The concept of a bolt-on turbocharger upgrade has always been a popular proposition for modifiers chasing moderate performance gains while retaining a factory appearance in the engine bay. As well as flying below the radar, bolt-on turbos can mean less custom work is required to make them fit up to things like intake piping, exhaust manifolds and the like.

Turbo versions of the BA, BF & FG Falcon are one of the most popular vehicles to modify in this way. With the various bolt-on turbochargers available today, owners are seeing numbers that not so long ago were the realm of big, high-mount turbochargers, built engines and custom manifolds.

In fairly stock form (injector upgrade, intercooler, exhaust, air filter, tune) our test car reeled off 307rwKw. Turbo Falcons have a water-cooled Garrett hybrid fitted from the factory and while it does the job on a standard, unmodified car, it falls over when you start to lean on the tune-up a little. This is particularly noticeable when the tuner asks for higher boost levels at higher revs. The graph below shows how, despite being asked to produce 20psi manifold pressure, the standard turbo just isn't up to the task and cannot maintain boost as revs rise.

The turbo we're replacing it with is a Precision GEN2 6466 CEA. This unit uses an internal wastegate like the standard turbo however the exhaust housing is dramatically different with wastegate priority in mind. This means that as the exhaust gasses enter the rear housing of the turbocharger it's the wastegate they see first. A larger wastegate valve and port and a stronger actuator mean no unintended boost drop-off and accurate boost control.

The removal of the factory turbo is very straightforward. With a few basic garage tools the air intake, dump pipe, turbo and exhaust manifold are easily removed.

Side by side you can easily see that the Precision unit is larger, both in wheel size and in length (not quite one inch longer overall). The factory turbo has a 53mm compressor wheel (inducer) and 62mm turbine wheel (exducer) compared with its replacement at 64mm and 66mm respectively. It features a stock styled actuator and will bolt up to a stock exhaust.

The dump pipe on the test car was larger than standard (XForce 4in) and needed a slight tweak for clearance on the bell-housing.

The Precision CEA bolted up to the factory exhaust manifold without any problems and once all of the accessories and factory style shields were refitted you’d be forgiven for thinking the car was unmodified.

Hitting the dyno rollers with Dale from Castle Hill Exhaust & Performance, we saw that not only was there a significant increase in outright power (420kW up from 300kW) but that, surprisingly, the larger turbo was making power sooner than the factory unit. When you consider that this was an internally standard engine on 98 octane pump fuel we can see why so many people are going this way for their turbo upgrade. Additionally, we already know how much the turbocharged Barra loves ethanol fuel and have seen examples making in excess of 500kW at the wheels with this turbocharger.

^{The finished product looks almost entirely stock but is capable of mega horsepower. Nice!}

Costs break down as follows:

Precision Gen2 6466 CEA bolt-on turbo - $2899

Labour - $700 (approx)

Tuning - $500 (add $800 if SCT X4 tuning box required)

Misc parts - $200

TOTAL: $4299 ($5099 if SCT X4 tuning box required)

***BONUS***

Book your car in for this upgrade in May of 2015 and receive the parts listed above for $4000 supplied, fitted and tuned. (SCT X4 box additional $800 if required).

Thanks to Castle Hill Exhaust & Performance Centre and RotorMaster for their assistance in creating this post.