Alloytec Awakening

Not happy with the performance of your Holden’s 3.6-litre Alloytec V6? Reckon it’s lifeless and lacks the on-demand torque of a typical Australian family car? Well, here a solution that’s impossible to ignore – a performance ECU reflash from PowerChip.

We doubt anything could touch this on a bang-for-buck basis.

PowerChip Alloytec V6 Tuning

According to Wayne Besanko, head of PowerChip, his company is the only one in Australia with direct ECU access for the Alloytec V6. Your only other engine management option is an interceptor (which we are yet to see tested on this particular engine).

The secret to Powerchip’s Alloytec tuning success is possession of the Powertrain Definition Program that is made available by Bosch to car manufacturers. The program used by PowerChip is designed for Saab but the Bosch ME 9.6 engine management system is the same as found in the Holden Alloytech. The Bosch program is presented in hexadecimal code so PowerChip use a commercially available hex editor to decipher tuning information. The editor also allows information to be graphed.

So that’s the approach - what tuning parameters can be altered?

Bill Ingram, PowerChip’s Technical Manger, say’s there’s the functionality to change everything in the factory computer. There are only a couple of areas, such as transmission control and closed-loop switch point, that are yet to be explored.

Fuel and ignition timing are adjustable at 192 points over the load and rev range. These points can be rescaled where necessary but extra mapping points cannot be added. Ignition control is divided into two maps – high and low octane maps. The ECU operates between these timing maps depending on the amount of knock that’s detected – if there is a lot of knock, the ECU will read from the more conservative low octane map.

“We advance timing at high rpm and make changes to both the high and low octane maps. We also increase the amount of maximum allowable advance so it can reach our target figures,” Mr Ingram says,

The PowerChip reflash is optimised to suit 98 RON fuel and ignition timing is advanced to just below the knock threshold. In situations where ultra high octane fuel is not available, 95 RON and normal unleaded tunes can be alternatively specified.

Interestingly, PowerChip is also able to alter knock sensor sensitivity and knock retard - although this is normally left untouched. According to Mr Ingram, the company tunes the ECU to deliver extra performance without relying on knock sensor feedback.

“In terms of fuelling, the standard tune is pretty rich – it runs about 10.7 or 10.8:1 [air-fuel ratio] . We adjust it to around 12.5:1. That’s where the engine likes to be – going leaner doesn’t give any more power,” Mr Ingram says.

PowerChip also utilises their ability to change calibration of the electronic throttle control - in other words, how much the throttle opens for a given accelerator pedal input. The throttle control map has 256 points of adjustment and, in a typical tune, PowerChip dials in a more aggressive throttle opening in the mid-throttle range.

“The throttle control maps give a lot of resolution near idle. With a standard engine there’s no need to touch any of that but it might be useful in a heavily modified engine,” Mr Ingram says.

The software also allows cam timing to be changed, though Mr Ingram says this there’s no need to because the factory cam timing is spot-on. The dual variable cam timing of the high-performance Alloytec V6 – the 190kW engine – is currently being explored.

Rev limit can be lifted if requested but, at present, this can cause fault codes in vehicles with an automatic transmission. Mr Besanko say’s they’re unlikely to pursue this problem as there’s no point revving a near-stock engine any harder – torque falls away well before the rev limiter.

The software also provides the ability to switch off various fault codes that may arise from other performance modifications. For example, it is possible to disable cat converter fault codes when the cats are removed for racing purposes.

So what is the reflashing process, you ask?

It’s a simple eight minute process. A laptop containing the new files is plugged into the car’s OBDII port using a dedicated flash interface. A few keystrokes later and the upgrade is downloaded.

Back-to-Back Drive Comparison

We compared a bog-stock Holden VZ Executive with its factory tune versus the PowerChip reflashed version (optimised for 98 RON fuel).

In standard form, the engine feels doughy, lacks the effortless feel of its Ford rival and top-end performance is ho-hum. Oh, and the engine sounds terrible at high revs.

Once reflashed, the Alloytec comes alive. Response is vastly improved in the everyday range of throttle application, there’s noticeably more torque (as evident by the transmission shifting up earlier) and top-end is much improved. The threshy Alloytec sound remains - but at least there’s now some performance to go with it!

Unfortunately, this particular vehicle had not been properly filled with 98 RON fuel prior to our back-to-back test. The tank had a 50:50 mix of normal unleaded and 98 RON fuel so, in an attempt to improve fuel octane, PowerChip added a bottle of Nulon booster. No detonation was heard at any time during our drive.

As seen in this graph, the PowerChip 98 RON tune achieves a considerable power gain in an otherwise bog-stock Holden VZ Alloytec. The standard curve (shown in green) maxes at around 109kW at the wheels while the tuned car (its power curve shown in blue) touches 121kW. That’s a gain of 11 percent. Look closer at the graph and you’ll also see a substantial torque increase through the mid-high rpm range. Note that these dyno runs were performed on a Dyno Dynamics chassis dyno.

Interestingly, Mr Besanko says the tune that’s suited to normal unleaded is only around 2kW down on the 98 RON version. The biggest difference is the extra ignition advance felt in other parts of the rev range.

Price and Verdict

The 95 and 98 RON reflashes are available for AUD$890 fitted or, if you’re interested in the normal unleaded tune, you’ll spend AUD$100 less. That’s a pretty attractive price – especially given you’re unlikely to achieve better all-round performance with conventional exhaust/intake changes.

The PowerChip is normally supplied with preset dyno-tuned mapping. However, if you want specific upgrades – such as a customised electronic throttle control strategy – PowerChip can accommodate.

Mr Besanko says their reflash doesn’t interrupt the Holden dealership servicing tool but it’s quite possible that changes could be detected if somebody went looking. In some instances, Holden may also flash a revised program into the ECU as part of a service update. If this occurs, the high performance PowerChip maps can be again flashed for a small fee.

Improved throttle response, more effortless commuting, greater torque and performance. What else could you want for well under AUD$1000?

Contact: PowerChip +61 3 9681 6888 www.powerchip.com.au