Just prior to heading away to The Big Red Bash, I dropped the HQ GU Patrol into our mate, Steve Etcell, from Automotive Etcellence (yep, that spelling is correct) in Riverstone in North Western Sydney for a tune and a service before heading to the Big Red Bash.

The HQGU is getting some km’s up now – at last look 180,000 on the old girl. We’ve also been finding that under continual load up long and winding hills that the Exhaust Gas Temperature was pushing a touch high, and we’d been meaning to get her tuned for a while, but not found the time.

With our trip to the Big Red Bash meaning we’d be towing a Track Trailer Tvan weighing 1500 Kg, we felt it was the perfect time to bite the bullet and get the tune done. Steve is a relaxed guy, and was very generous to fit us in for both a tune and a service with just 24 hours notice.

I turned up there and decided to spend the day working from Steve’s office so I could hassle him and understand more about the tuning process, and truth be told I learned a lot. And just to clarify, I’m talking about a flash tune here, where the vehicles ECU programming is overwritten to improve vehicle performance.

What’s involved in a Flash Tune?

Conceptually, I had this notion that tuning was about connecting a computer to the vehicle’s ECU, putting it on the dyno and then fiddling to optimise the output. In the end, I was kind of right, but I missed a lot of detail.

The first thing Steve and his team did on the HQ GU was put it on the Dyno to get a baseline and some diagnostics. The HQ GU put out an initial 85Kw and 381Nm (at the rear wheels) to start.

As soon as this was done, they had to locate and physically remove the ECU. It turns out it is located up under the dash of the GU Patrol, and unlike most other vehicles it needs to physically be removed from the vehicle to be tuned. Most modern vehicles have an OBD port which allows you to connect a computer and direct tune a vehicle without physically touching the ECU, but not our old girl!

Next, a computer was connected which uploaded the current setup and diagnostics to RD Technik (a specialist vehicle tuner), who start with a mapping which is specifically designed for your vehicle make and model, then analyse the diagnostics they receive to customise the tune to your vehicle. Steve tells me that even two identical vehicles will never end up with exactly the same tune!

This program is then written back onto your ECU (and in our case the ECU was loaded back into the vehicle), and another Dyno run is completed. If further adjustments or fine tuning is required, the data from the latest Dyno run is uploaded back to RD Technik, and then the process continues. In some cases, this can be 2-3 runs on the Dyno, but others it can be a lot more.

How long does it take?

If you are wanting a tune, be prepared that it could take a full day to get right, depending on the vehicle

What are the benefits?

There are many benefits of tuning your engine, but the most obvious is a performance increase. The simple truth is that a stock vehicle’s engine was tuned to meet an emissions standard rather than maximise performance. When you tune the engine, you’ll not only get power and torque improvements, but the engine will breathe better as well. It feels like it produces more power by working less. And you’ll notice it in improved fuel economy too.

Will it reduce engine life though? This is a question I asked of Steve. With his knowledge of engines and performance, Steve reckons that it will actually prolong engine life because the engine works at its optimal level.

In the case of the HQ GU, the first tune increased the Power at the rear wheels from 85kw to 99.8kw, and from 381.7Nm to 489.3Nm. Impressive, given we had asked Steve to do a conservative tune given the km’s the GU has travelled and our desire to play it safe.

The other benefit of an RD Technik flash tune over purchasing a piggyback module is that the flash tune retains all of the engine safety parameters set by the manufacturer. This means that if the original tolerances are exceeded, then the engine will drop into limp mode if required, or show the engine trouble or other light. This is piece of mind because it means that the new tune still operates within the safety tolerances specified by the manufacturer. The same is not certain of a piggyback chip.

Does it need re-doing?

The great thing about a tune is that it doesn’t need to be re-done again. Unless you make modifications to the engine like fitting a bigger turbo, adding an intercooler, or upgrading the exhaust, it is a one off thing that you do.

What was our experience?

We found that the tune did wonders for the GU Patrol. With the tune, we’ve really noticed the torque increase and the resulting reduced Exhaust Gas Temperature because the engine is no longer over-fuelling. We were able to tow at highway speeds which the GU Patrol would struggle with previously (even without towing), and have also noticed improved fuel economy. I’m only a quarter of a tank through running the Patrol without any extra weight behind it, but so far I’m tracking a 15% improvement in fuel economy based on the distance I’ve travelled vs what I’d usually get from that part of the gauge.

The best part about the tune for us is that there is a noticeable improvement in torque down low, and the engine feels like it isn’t working as hard. We’ve noticed the improvement, especially when towing the new Tvan.

The other thing that was interesting to note was that the ECU tune improved performance over and above the aftermarket module that was already on the vehicle, while maintaining significantly lower EGT temperatures under load.

Who are Automotive Etcellence?

Automotive Etcellence is a 4WD specialist based in Riverstone, Sydney. They cater for everything from everyday servicing to custom modifications – they’ve always got some really special vehicles in the workshop! They are also a TJM retail store meaning you can buy parts directly from them and have them fitted. You can find them on Facebook or their website.

RD Technik is a specialist in performance tuning. They analyse the Dyno runs, then check the stats against a database of previous tunes and diagnostics from the same make and model to write a custom program which is sent back to the tuner to upload and then re-run the vehicle on the Dyno. The benefit is a tune that is specifically optimised to your vehicle.

If you’ve tuned your vehicle, what kind of tune did you get done, and what was your experience with it?

Aiden