TURBO TAXI
OUR BIG YELLOW TAXI IS ALMOST READY TO HIT THE TRACK WITH SOME BOOST
Our dirty old taxi is dripping with new, boosty hotness
EPISODE two of our new video show,
Carnage, hit the web in late April, continuing the story of our Turbo Taxi build. Judging by the response, it seems like everyone is keen to see if we can make an old taxi go 10s on LPG.
Last month we’d just finished doing an engine swap; we found a low-kilometre naturally aspirated donk on Facebook for $200. The price was right, but taking four days to slot in the uncooperative engine certainly took a shine off things. Everything that could go wrong did go wrong, and you can see our struggle first-hand by checking out the video on streetmachine.com.au.
Since then we’ve been plenty busy. We drove the taxi around for a week or so before the radiator decided to drop its guts on the side of the road. The guys from Glenlyon Motors helped us get the Falcon back in action while I was away on a mountain retreat. We reckon it was a combination of age and a dodgy temp sensor that caused the blow-out.
A lot of people have asked why we didn’t do the turbo conversion when we changed the engine over, and the answer is simple – we didn’t have any of the parts. But we had an engine and a video schedule, so we elected to get things moving along. By the time I had returned the turbo parts were ready, and so we jumped straight into the heavy-duty stuff.
With time pressing, we got the guys from MPW to help us with the Plazmaman intercooler installation – they do this kind of stuff day in, day out, so it made a lot of sense to get them involved. For our set-up we chose the Plazmaman Stage 3 1000hp intercooler kit and grabbed a four-inch intake and battery relocation kit to go with it. The ’cooler kit comes with all the necessary silicon hoses, clamps and pipework, and all the parts are premiumquality – no Chinese hose clamps here. The kit is designed to go in with the minimal amount of cutting, but that’s when it’s being fitted to an XR6 Turbo or FPV F6. With our car being
a base-model XT taxi, the front bar needed more work than a Kim Kardashian photoshoot before it would clear the pipework from the intercooler. As for the four-inch turbo intake pipe and the battery relocation kit, they were almost a direct bolt-in, with just a couple of holes needing to be drilled for the new battery tray and earth lead.
After that was all in, the guys moved on to other jobs around the workshop and left me to fit the new exhaust manifold and turbo and generally get the car ready for the next stage.
We managed to snag a good second-hand FG turbo exhaust manifold from Zane at Maxx Performance in Dandenong. Zane also sorted us out with a much stronger tailshaft. In their experience – and they specialise in BA/BF/FG turbo Falcons – the standard tailshafts let go at around 380-400rwkw, and with our plans for more power we decided to be proactive and drop a stronger unit in now. While the two shafts look identical when laid on the floor side-byside, the new unit was significantly heavier due to increased wall thickness. The guys get them custom-made and they reckon the beefy shafts are good for up to 600rwkw.
Back on the hoist at MPW, we closed off the LPG tank tap and disconnected the gas converter before removing it completely. The factory E-gas converter sits on the exhaust side of the engine bay, basically where the turbo would sit, so it had to go.
Our turbo is a custom unit built by GCG Turbos in Sydney. After talking with the guys about our requirements they put together this custom Garrett GT35/84R, which is a fair bit larger than the factory FG turbo. It uses the same 1.06 A/R rear housing as the factory turbo, but with an enlarged wastegate port and flapper along with an aftermarket Gcg/turbosmart wastegate actuator. As delivered, the turbo is set for 14psi, but they’ve included an extra 5psi spring to bring things up to 19psi when we go for maximum boost; hopefully that will be enough.
On the compressor side of the turbo we’ve
got a surge-slotted 0.7 A/R front housing with a 68mm inducer and an 84mm exducer on the billet compressor wheel. Its maximum power rating is somewhere between 900 and 1000hp, which is plenty for our needs. We had a few comments on our second
Carnage video about the fact that I set the turbo up with the oil feed pointing straight up, which is the way that factory BA and BF Falcons are set up. It seems that in the FG range the housing is canted at around 20° to help with water flow through the turbo, something that Garrett calls ‘Thermal Siphoning’. This can reduce the temperature in the centre housing by as much as 50°C, but to do this the water intake side of the turbo must be positioned lower than the outlet on the other side. If it’s the other way around it can cause temperatures to spike and shorten the life of the turbo. But straight up and down is fine too, and because our turbo water feed pipes seem to be Ba/bf-style, we’ll stick with that.
On the intake side of the engine we found a near-new FG Falcon turbo intake manifold on ebay, complete with injectors and throttlebody. At almost $600, it was probably a bit more than we wanted to pay, but after dealing with the old ‘dual-band’-style intake, and the possibility of doing another engine swap, we wanted something that was going to be easier to get on and off the car. Rather than bolt it straight to the car we dropped the intake off to Jason at Tunnel Vision so he could drill it for a second set of LPG injectors. Jason has been piecing together everything we need for a vapour injection system to support the power requirements. None of the factory gear was up to the task, so he’s run twin 10mm high-pressure lines up to the new lock-off valves and twin gas converters. From there the converters will feed the LPG injectors, which look a lot like old-style Bosch fuel injectors apart from a couple of differences. Once it’s all together the engine will look like an EFI petrol set-up to most people. To control it all we’ll be using the Haltech Elite 2500; it’s got the capabilities to control two sets of injectors and work with the
factory drive-by-wire throttlebody. What we’re planning to do is see how quick the taxi will go on low-ish boost and one set of injectors first, and then crank it up and add the second set.
While Jason was sorting that out, we shipped the car down to Andrew at Extracted Performance Exhausts. You may remember Andrew as the guy who did the great exhaust on Project Swinger, and being located within five minutes of MPW and Tunnel Vision made him an easy choice for our system. For our turbo Barra set-up, Andrew pressed the dump pipe out of malleable 409 stainless using his own custom dies, and then made the rest of the system out of four-inch-diameter 304 stainless. It’s a race-specific system and a pretty chunky looking piece of pipe; honestly, we can’t wait to hear it fire up for the first time. That four-inch pipe will probably push us down the quarter using thrust alone.
And that’s where we are at right now. At the time of writing the taxi isn’t quite running again, but it should be within the next couple of days. By the time you read this, the next video instalment of the Turbo Taxi build will be on streetmachine.com.au; we’re as keen as you guys to see this beast run.