The troopy was already fitted with a DTS aftermarket turbo system when we bought it. To begin with we were not sure if we wanted the added complication of an aftermarket turbocharger. However after driving the troopy even with the turbo fitted I can’t see how you’d get around with out it. Slow would be an understatement. The 1HZ motor was never meant to be a powerhouse but with the auto gearbox and constant all wheel drive combined with all the weight we were going to be carrying it would seem to be seriously underpowered.
Maybe that’s just me and I’m used to my old petrol patrol, sure there’s plenty of people who’ve done big road trips with the standard setup. There’s probably plenty of people out there with the standard 1HZ who swear buy it. Also heard people saying the slower your vehicle the more of the world you see. Well bugger all that I refuse to own a vehicle that gets overtaken by B doubles let alone drive it around the world. So power rules supreme.
In saying that reliability is probably the more sensible option so why not have a balance.
The turbo stays but I have done everything to make the setup as reliable as possible.
Starting with the fundamentals, when we rebuilt the motor I opted for the strengthened AE pistons. There are no pistons made for the 1HZ that are suitable for turbo applications so we went with the strongest on the market.
We had the injectors reconditioned and the cracking pressure increased to suit the higher compression pressures. The diesel pump has been rebuilt and calibrated for the optimum fuel mixture when on boost. The previous owner had the fuel mixtures set way to rich meaning excess fuel caused the combustion temperatures to sky rocket ultimately cracking the cylinder head.
To keep the inlet air temperature down we decided to fit a top mount intercooler. Cooler air is also denser meaning more oxygen and more efficient combustion. The HPD intercooler came fitted with a 9″‘thermo fan this helps to draw cool air though the intercooler.
With the aid of a bonnet scoop to direct air to the cooler. This took some mucking around because the previous owner had already fitted a bonnet scoop above the turbo to help ventilate the engine bay better. Problem being that it is offset to the left. Thankfully HPD provided a much wider bonnet scoop, which meant we had to cut a larger hole in the bonnet. The previous scoop was also much longer so when we removed it there were mounting holes that were going to be exposed as well as two 20mm holes that had been cut into the bonnet for some reason. Also removing this section of the bonnet meant the main reinforcing also had to go to make clearance for the cooler. The bonnet then lost a lot of its structural rigidity. Because of this we decided to weld in some brackets to reinforce the structure of the bonnet. Once this was all done next came the bogging, gap filling primer, paint, clear coat then buffing. What a lot of work just for a scoop but it all turned out better than expected even the home job painting.
A few other devices we added to help manage the turbo system was a boost gauge, exhaust pyrometer, turbo timer and boost controller..
The exhaust pyrometer monitors the temperature of the exhaust gasses exiting the turbo this helps to get an idea of how efficiently everything is running. The particular brand I chose also had the optional output relay and alarm. Meaning that at a set temperature we could use the gauge to trigger a device. This was perfect for the thermo fan on the intercooler. So for example when the exhaust temp reaches 200 degrees the pyrometer triggers a relay to turn the fan on. Once the exhaust gas has cooled to 150 degrees it then cuts out.
The Pyrometer also had an alarm function so that when exhaust temp becomes excessive we will have an audible alarm to let us know. 500 degrees is about the max temp you want to allow.
All the literature referring to the intercooler claims that you get power increase to 153kW and torque increase to 430Nm. Clearly this is not achieved just by fitting the intercooler. According to HPD you can wind up the boost to 12psi. It runs about 9psi normally. I am a bit reluctant to run 12psi constantly putting extra stress on not only the engine and turbo but also various driveline components.
However a little more power won’t go astray when overtaking or claiming big hills. For this reason I fitted a dual stage boost controller which allows me to flick between 12psi and 9psi on the fly. We also fitted a Speco boost gauge to monitor that the boost levels are on target.
Last but not least a turbo timer was already fitted to the vehicle. This allows the turbo to cool down gradually after a long run and when they ignition key has been removed. You can remove the key and lock the doors but the engine will remain running for a set time before shutting down on its own.