A date with the dyno.
In our last installment ("The Blown Ranger," Dec. 2005), we walked you through the installation of our awesome Explorer Express Supercharger kit. Normally we would have hit the dyno right away to give you the results, but we had a few extras we wanted to add to the truck before heading out to get the numbers.
Advance Engine Management (AEM), of Hawthorne, California, heard about our project and offered up one of its trick new Dry Flow synthetic air filters that we also told you about, along with its wideband UEGO AFR system. The good folks at AEM also graciously offered to install our Auto Meter boost gauge and Auto Meter pillar pod at the same time as the UEGO gauge.
In addition, Doug Studdard, owner of www.BamaChips.com, who provides all of the base tunes for Explorer Express customers, offered to meet us at JBA Racing's Performance Center in San Diego, to custom tune RangeRunner on the dyno. Doug is highly regarded on most Ford Internet forums and in Ford circles as the expert when it comes to Ford 4.0L V-6 (Explorer/Explorer Sport Trac/Mustang/Ranger) computer tuning, especially on forced-induction applications. So, it was much to our advantage that shortly after completing several weeks of working overtime to help to fix the damage caused by Hurricane Katrina, that Doug found the time to fly out from his Alabama home to meet us in San Diego for our dyno run.
It is important to know that dyno results are more reliable when before-and-after runs are done on the same machine, and rather than focusing on the ultimate numbers, it is more important to look at gains in terms of percentages. That being said, JBA Racing's Dyno Dynamics dyno is the same unit we originally used to baseline our Ranger with only an aftermarket intake on it. This type of dyno reads approximately 15 percent more conservatively than the more commonly quoted Dynojet. This is an important distinction to consider when quoting numbers, as overall outputs can be inconsistent from dyno to dyno. Keep in mind: Dynos are not the final word, but rather one instrument in the toolbox of engine tuning. The final results on RangeRunner include the aforementioned Dryflow filter, Explorer Express blower, and previously installed JBA Cat4ward headers and Evol exhaust.
AEM provided one of its trick new Dryflow synthetic air filter elements to the project. This filter material has superior filtration efficiency, important when your blown engine is sucking in dusty air. The major benefit to the reusable Dryflow is that it is a non-oiled filter, so you don't have to worry about fouling your Mass Airflow Sensor by over-oiling the element during cleanings.
Originally rated at 207 hp and 238 lb-ft of torque at the crank, our final dyno run saw our output - running 91 octane, on this very conservative dyno--jump to 225 hp at 5,779 rpm and 257 lb-ft of torque at 3,339 rpm. If you consider a 20-percent drivetrain loss, this equates to approximately 270 hp and 308 lb-ft of torque at the engine (about a 61 percent gain over our previous run with headers and exhaust). Also consider the fact that 91-octane is generally the highest rating that's widely available in Southern California, so Doug gave us a higher horsepower program to run if we can (a) find 93-octane and (b) afford it.
How It Feels
Shortly after leaving the dyno with the now livelier RangeRunner, we've been driving all over town, toying with unsuspecting drivers. The truck feels perfectly normal and docile under light throttle, but step into it, and a fierce shriek emanating from under the hood lets all within earshot know this isn't a stock engine under the hood of our Ranger. Another benefit of the blower is that downshifting on long grades is no longer needed. What once required Fourth, or even Third gear, can now all be done in Fifth, all while getting better fuel economy when we are not pressuring the skinny pedal. With all of the things we have planned for RangeRunner in the coming months, this should be one wicked ride in the dirt.