IT’S been a busy few months here at Street Machine as we turn our 2010 FG Falcon taxi from high-mileage cruiser to quarter-mile bruiser. The build is all part of our new video series Carnage, and the Turbo Taxi is the first of what we hope will be many exciting projects.
For those checking out the Turbo Taxi for the first time, the plan is pretty simple: Take an original high-mileage taxi and make it run 10-second quarters while keeping it running on LPG.
Over the years there have been a few people who have repurposed old taxis in this fashion, but they’ve all been converted back to unleaded or E85, as most deem it too hard to get the performance out of LPG. So the very first person we called when we originally conceived this idea over a couple of lunchtime burgers was Jason from Tunnel Vision. Jason has a reputation for building tough sixes and extreme LPG installations, the most notable of which is John Colaidis’s Barra-powered Ford Mustang, which ran high eights on LPG before it was converted to E85 (it now runs low eights). However he doesn’t just deal with quick sixes; Jason also tunes ‘Bubba’ Medlyn’s Street Machine Drag Challenge-winning VH Commodore and Harry Haig’s turbo big-block HQ sedan.
So we put the question to Jason: How quick could we make a stock Barra-powered taxi go while keeping it running on LPG? Tens was the answer, but he also said the main problem would be getting enough fuel to the engine. However, he liked the technical challenge of the idea.
“I don’t do a lot of LPG cars anymore,” Jason admits. “The problem is that most people think LPG equals cheap, and it’s not. A set-up like I’ve done on the taxi is going to be over $12,000, including the ECU.”
There was also the question of how much horsepower the LPG injectors would support; no one knew, but it was clear we’d probably need two sets. So Jason gave us a shopping list and told us to give him a call when we were ready. The biggest thing on the list was the Haltech Elite 2500, which has the capability to work with drive-by-wire and has a multitude of injector drivers and ignition outputs. Haltech is actually working on a plug-in unit, but it’s still a couple of months away.
When it came to wiring in the Elite 2500, Jason got in a local specialist, who everyone simply calls Peg, to handle the massive amount of wires that the guys have piggy-backed onto the factory
ECU. Paired with the wideband controller, the ECU has the ability to adjust its tune on the fly.
But there was no such thing as a base map for our custom set-up, which meant that Jason had to create something from scratch.
From our side of things the tuning seemed simple, but we’re sure Jason will tell a different story. There were a couple of late nights while he worked out things like cam phasing and boost control, with the two ECUs seeming to battle each other for a while. Once he got it all sorted, the Falcon began to run and drive like a normal car. We did some road tuning before throwing the taxi on the dyno at MPW, and with just 9psi boost the car was feeling strong. On the rollers the Falcon reeled off 338.9rwhp (252.7rwkW) for its first run, and after a quick check of the data Jason felt it could handle a few more ECU P i d i h h id b d ll h degrees of timing, which bumped the power up to 363.3rwhp (270.9rwkW). We were pretty happy with that to start off, and with the next street meeting at Calder Park the very next day, we were keen to get it out to the track and test it.
At Calder there were plenty of fans eager to see the taxi run, and we were looking forward to testing out a little feature that Jason had set up for us – the car now has a two-step rev-limiter for launch control.
For the first run I decided to not use the twostep; I wanted to just get the car down the track and make sure nothing was going to fall off or break. With no boost on the line the taxi was very slow over the 60-foot mark, but then it came on boost to run a firstname.lastname@example.org. It was an okay run, but we knew we could do better; the mph figure was a good indicator that 12s were there d f i i hi h b d h for the taking. The next run was supposed to be our victory dance, but I screwed up the launch.
With my foot on the brake and the handbrake pulled up as well, I pushed the two-step button and mashed the throttle. At 2800rpm I heard the bop-bop-bop of the limiter and released everything – including the throttle. I cursed myself and mashed the throttle again but the boost was gone and the time board told the story: email@example.com.
I did basically the same thing on the next run to get a firstname.lastname@example.org; the launch procedure required simultaneous release of the handbrake with the left hand, the foot brake with the left foot and the two-step button with a finger on the right hand, all while keeping the right foot to the floor. It’s hard to remember all that while the tree is counting down. So I decided to simplify f h ki T
the procedure for the next pass. Using just the foot brake and the two-step I was able to hold the taxi on the line while the revs climbed to 2800rpm. On the launch the acceleration felt awesome, but you could feel there still wasn’t enough boost on the line to really get the taxi firing. At the other end of the track the timing board gave us email@example.com; good, but not good enough. The last run was no better, with a firstname.lastname@example.org. We just weren’t getting enough rpm, and therefore boost, on the startline. We tried raising the two-step limit but the converter was at its limit at 2800rpm; it would go no further.
Obviously we were a little disappointed not even running 12s first time out, but the night gave us some valuable data. Jason could see that while the fuel system was close to capacity, there was room for a little more boost, so the choice was a new converter or more boost.
Why not both, I thought. In my travels through the interwebs I see a lot of parts for sale, and I remembered seeing a converter for a four-speed auto being offered. A quick search found it was still for sale, so I offered the guy $350 and the deal was done. We’d just raced on a Friday night; I had the new converter Sunday afternoon and was at MPW putting it in on Monday.
On Tuesday we had Andrew from Extracted Performance Exhausts add a couple of straightthrough mufflers to knock the edge off the extreme exhaust note, and that afternoon I was asking Jason for more boost. Naturally he wanted to know why we needed more boost with no racing meetings scheduled for several weeks, so I told him straight.
“I’m driving this thing to Sydney to race on Wednesday night!”
He just looked at me and said: “You’re nuts, what are you going to do if you break it?”
“I’ll fix it,” I said, and Jason just shook his head.
Still, he dutifully maxed out the fuel system with a few more pounds of boost, and after a quick road tuning session I hit the road to Sydney.
I had my wife pre-book me a motel room in Albury that night and I rolled in at 10.30pm. The next morning I filled up with a fresh tank of LPG at 8am and pointed the big yellow taxi north. On the open road the Turbo Taxi cruises like a normal car, although it does have a habit of freaking out the cruise control when the extra load of a hill starts to bring the boost on at 2250rpm. The first time that happened certainly freaked me out too; this thing accelerates like a rocket.
OUR original plan was to use a Gas Research gas mixer and see if that would work, but Jason was concerned about the issue of backfires, which have been a constant problem in the past. On a stock bottom end like ours, backfires equal death. The only way to completely eliminate the possibility of backfires was to go for EFI; Jason gave us a price and a shopping list of bits to get from Haltech.
That’s how it all started.
Now there are some parts that Jason just wouldn’t tell us about. “I’ve got to have my secrets,” he says, but we can give you the basics.
The dual factory LPG tank system was the only part of the original gas system that was used in the new LPG EFI system, and even it came out for some mods. Twin 10mm lines run forward from the tanks to the dual lock-off valves. These valves are for safety; they’ll close off the LPG flow when the engine isn’t running, so if the engine stops in the event of an accident, for example, the LPG stops flowing.
From the lock-off valves there are twin gas converters, which convert the LPG from liquid to vapour; we’re running a vapour injection system rather than a much more expensive liquid injection system. Twin lines from the converters feed a custom distribution block with three lines from it to the fuel rail; each feed sits between each pair of injectors.
From the outset Jason knew that one set of injectors wasn’t going to get the job done, so he planned to run two sets of LPG injectors, but the pressure of video deadlines meant that we only had time to get one set plumbed in for the moment.
The holes have been drilled and tapped for the second set of injectors, but they’ll be plumbed in at a later date.
Two fuel stops later I was pulling up in the car park at Plazmaman in Wetherill Park. The taxi had averaged around 14.5 litres of LPG every 100km and felt just as good as ever. After a quick catch-up with the Plazmaman team and some impromptu two-step action in the car park, we ducked around to Haltech for a look before heading to Sydney Dragway.
Now we didn’t plan it this way, but with the State of Origin on there wasn’t a massive amount of cars at the track. SM features editor Andrew Broadley and freelance video master Matt Reekie were there to cover the action, with Joseph Lenthall and Liam Quirk from the advertising team also lending a hand, which was just as well because I was starting to feel the dreaded man-flu coming on.
During scrutineering we put the taxi over the scales and it was 1761kg without driver; with me on the scales as well the overall figure wasn’t pretty: 1896kg!
With 18psi in the 255 drag radials, I faced the line at Sydney Dragway for the first time in years. With no concern for reaction times I let the tree come down as I built boost on the line.
We’d reset the two-step for 3100 and as soon as the familiar bop-bop-bop sounded I released the button and stepped off the brake – and the accelerator. But I jammed back down on the go-pedal and launched, and boy did that taxi go!
All the way up the return road I was cursing myself for letting off the accelerator. Unlike Calder Park, at Sydney Dragway you’ve got no idea what time you’ve run until you get back to the timecards, but passing through the burnout pad I could see Matt there with a big grin and a thumbs-up.
“12.34 at 116,” he shouted, and I punched the air. With a shit start like that, it still ran 12.3? I was over the moon. The timecard confirmed it and I lined up for another pass; maybe an 11 this time. But at the line I didn’t give the brake pedal enough love and the car pushed through the start beams; it still ran a email@example.com but I was kicking myself for wasting a run.
Back around to the staging lanes, and word was starting to spread that I’d driven up from Melbourne to be there; people were beginning to realise that this was ‘that car they’d seen on FaceTube’. For the next run I made sure there was plenty of heat in the tyres, but I noticed the engine was running pretty rough after the burnout. The launch was textbook, and I was confident of a very low 12, maybe even an 11, but Matt gave me the bad news: firstname.lastname@example.org.
I mean, sure, it was the quickest run to date, but we were down a whole 2mph for no reason and I was starting to wonder if we’d hurt the engine.
Remember this is just that same $200 petrol motor that we installed during Episode Two of Carnage. I also considered that the burnout might be putting too much strain on the standard valve springs, so I decided to try no burnout. It was worth a shot.
On the launch the tyres spun and our 60-foot time was two-tenths off the pace, but at the other end we ran a 12.65@117mph. Obviously the wheel-spinning start wasn’t optimal, but high mph shows the potential of the Falcon, and it was clear the burnout was definitely having an effect on the valve springs. We chalked that one up to a learning experience and headed back around for one more pass.
With 9pm approaching the Sydney Dragway team were getting ready to switch over to burnouts, so this was definitely going to be the last run. Unfortunately it turned out to be a waste of time; on the two-step one of the back tyres went up in smoke, and it didn’t get any better when I released the button. I only managed a 15.3@110mph, but overall I was still pretty happy. I’d just driven 894km, ran the best times the car had ever done, and it was alive to drive home again.
Back in Melbourne, I drove the Falcon straight to MPW on Thursday afternoon and got the guys to throw it on the dyno, curious as to what it was making now. With 117mph trap speeds we knew it was making more power, but backto- back runs of 438.1rwhp (326.7rwkW) and 440.9rwhp (328.8rwkW) certainly put smiles on our faces. It wasn’t so long ago that 440rwhp was serious power, and here we were making that with a standard engine and LPG at just 13psi boost.
However successful the trip was, it did reveal a couple of problems. We’re definitely going to be changing the valve springs before we hit the track again, and it’s time to throw in that XR8 LSD rear end for more traction. As we go to press, we’re doing all we can to get ready for our next scheduled track appearance at the Australian Ford Forum drags at Heathcote Park Raceway. That will be run and done by the time you read this, so hopefully the Turbo Taxi will crack the 11s. Then we’re going to add that second set of injectors and see where that takes us on the standard engine.
Check back with us next issue. s