"it feels mighty strong, mighty pumped and totally together"
Motor Magazine
| ECU Edit Study |
| With the arrival of tuning software that allows editing of the factory Ford computer, a great deal of emphasis has been placed on the features and peak power output . More often than not however, the quality of the engine's power delivery is overlooked.
The XR6T performance enthusiast must never lose sight of the fact that the fundamental role of an engine tuning device is to optimise the engine tune - resulting in higher engine performance. One would expect that higher engine power results in quicker acceleration - and this is often the case, however a higher power figure does not necessarily give an indication of the smoothness of power delivery or indeed the rate of acceleration of the vehicle. For example, let's consider the dyno chart below. |
| This dyno chart graphs power at the wheels (albeit, this brand of dyno displays very low outright power figures) versus speed. Regardless of the power figures themselves, it is the shape of the each curve that is important.
The above XR6T vehicle was fitted with an ECU edit program available over the counter and delivered 3 modes of operation. Standard map, 8 psi map and 10 psi map. This is also the first of the new breed of "one size fits all" preprogrammed tuning options for the XR6T distributed to all and sundry who wishes to purchase it. The vehicle was first tested with the standard setting and the resultant power graph corresponded well with the standard vehicle. In other words, the shape of the power curve and the values obtained were essentially the same as that for the standard vehicle. Next the 8 psi map was loaded into the engine's computer as per the manufacturer's recommendations and run again. Immediately the outright power figure at the wheels increased by 18 kW - a level of improvement that can certainly be felt on the road. However, this power improvement was not really indicative of the performance improvement. Consider the 8 psi graph shown above and in particular the shape of the curve compared to that of the standard setting. The 8 psi power curve resembles that of a roller coaster and oscillates between higher than standard power values and standard values. In fact, at some points high in the engine's RPM range, the 8 psi setting delivers less power than the standard setting. The end result was an XR6T that felt quicker than standard, albeit with inconsistent power delivery but with a rate of acceleration lower than the 18 kW improvement would suggest. After analysing the 8psi results, it was deemed that there was little point in loading the 10 psi map for further evaluation. The 10 psi map has already built a reputation as being problematic - and qualitatively, inferior to the 8 psi map. In addition, there was little reason to persist and potentially cause damage to the XR6T engine given the erratic results obtained with the 8 psi map. The product was removed and the engine's computer returned to standard. |