Towing Power Upgrades

Knowledge is power. As there’s no substitute for power when towing, this knowledge is invaluable to boost your performance.

By Anthony Kilner

It’s not often I have to put a vehicle into low-range to take off at a set of lights while facing uphill. The other day, with a fairly light 20ft caravan in tow, I had to do just that to avoid stalling the Cruiser yet again. This was a somewhat scary moment and I realised it was not a safe way to tow.

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My 2002 factory turbo Cruiser has struggled since day one just to haul our Ultimate camper up the driveway; mind you, day one was only 12 months ago for us. In issue 003, I mentioned a DP Plug ‘N’ Go pedal chip that was fitted to my Cruiser at Piranha Off Road as the start of an exploration of chips, pedal chips and tuning as a way to get more power out of the engine. Well I am pretty rapt with the result so far and there’s a good story to be told.

We decided that before we did any dyno or fuel testing to set a base for our experiments we should service the Cruiser. After steering the ant-mobile up into the mountains of Belgrave, I arrived at ATOC Automotive where we started servicing the fourby from one end to the other. The timing was perfect as the rear brakes were about to go metal on metal, and we found several other issues that needed to be addressed.

Putting any vehicle on a dyno means it will be working hard. In my case we flushed the cooling system, fitted a new thermostat and fan on the coupling along with doing all the tappet clearances, oils and filters – all in the hope the Cruiser would perform at her best on the dyno and on road.

With the servicing done it was off to Piranha Off Road to get the DP Chip and Plug ‘N’ Go fitted. We found a no-name brand chip already fitted in the Cruiser but made sure we could disconnect it and run the motor and dyno it standard. With the DP and the no-name chip run separately, we also tested the set up for the Plug ‘N’ Go with a block under the accelerator to measure the differences between the major settings on the unit. Just these runs alone were amazing to see on the chart.

My anticipation was growing as I rocked up to the Horsepower Factory in Dandenong to start the dyno runs. Matt Jackson was on hand to explain the procedure and Marty Rogerson was taking control of the actual testing. The end result was a 20 percent gain in power over standard with the DP Chip and some amazing graphs showing just the basic settings on the pedal chip.

 Seat of the Pants Testing

Dyno work is great at showing the facts in a no-nonsense way, however, it’s behind the wheel where these add-ons can make all the difference in the world. I have a very steep hill climb on my road and under all conditions with the no-name chip I could only drive up in first gear. Despite the fact that on the dyno this chip showed more power down low and towards mid-range, this set up just simply couldn’t take on an uphill slope with any gusto. With the DP Chip fitted I can drive up this hill in second gear without a struggle.

Towing and on longer runs, I found the Plug ‘N’ Go and DP Chip combo to work smoothly. I have found my throttle sensor to be a bit worn which means I can’t use the most aggressive take off setting without sending the Cruiser into limp home mode. This is not too much of an issue because there are over 14 other settings on the pedal chip to compensate for my throttle controller issue. I also checked with DP Chip that this was okay to do and they reckon that’s perfectly good and saves me some bucks buying a new controller.

In the bush the green setting delivers good take-off power with the Ultimate on the back, and while on-road I have found the red setting to be fun without the aggressiveness. Towing-wise Jane and I went for a quick run through on the blacktop to Mansfield before a High Country cruise with the Ultimate and found the Cruiser towed far more effortlessly. I was able to maintain 100km/h up hill and down dale, leaving me very happy with the end results overall.

Over the coming weeks I’ll be doing some serious towing as well as fitting up a Redback exhaust system to see if that can make the Cruiser even sweeter and safer for towing on and off road.

What’s in a Chip

DP Chip has been around for about 15 years and Andrew Leimroth from Berrima Diesel explained that the chips are designed to extract solid power from the motor without overstressing it. Gains of between 15 and 20 percent are what they aim for. The chip essentially alters the way the ECU delivers fuel and therefore power.

The Plug ‘N’ Go, on the other hand, has three main settings, Green, Orange and Red with three higher and three lower settings in each. This means 21 settings in total. This unit adjusts the responsiveness of the throttle according to the throttle position.
For such an easy unit to fit and play with, the results are simply amazing.

The DP Chip retails for $1495 plus fitting while the Plug ‘N’ Go retails for $399, plus fitting.

Fuel Figures

As with all things, when there is more power available, then the tendency is to use it. At least I certainly tend to drive that way! As a part of this experiment I have done some fuel economy runs and will do a couple more for the next story. As I live in the hills, which are quite steep in places, and so use more fuel than someone living in flatter suburbs would do while just driving around.

Best possible fuel economy run
No-name chip in place
8.73km per litre
– 11.45 litres per 100km

Around Town Fuel figures – no towing
No-name chip in place
6.30km per litre
15.87 litres per 100km

Melbourne to Yarrawonga
Minimum Green on pedal chip & DP Chip fitted.
110km/h on Hume – cruise control on.
6.71km per litre
14.90 litres per 100km

Yarrawonga to Melbourne
Maximum Red on pedal chip & DP chip fitted.
Speeds up to 110km/h where allowable.
7.08km per litre
14.12 litres per 100km

Towing around Melbourne
No-name chip
5.63km per litre
17.76 litre per 100km

Towing the Ultimate from Eltham to Mansfield through the High Country and Eltham via Marysville.
Trying various settings on the pedal chip & DP chip fitted.
5.33km per litre
18.76 litres per 100km