Heat vs. Heat: Comparing Oil Temperatures
ProCharger's P-1SC is a self-contained supercharger, as opposed to an oil-fed unit where engine oil is plumbed into the blower to lubricate it. Since one of the common knocks against self-contained superchargers is the myth that the lubricant inside the blower's case becomes excessively hot as blower speed increases, we decided to perform a temperature-comparison test to find out if there were any differences between the engine-oil temperature and the temperature of the oil inside the blower.
ProCharger technical ace Dorian Comeau set us up with a test version of the P-1SC, which included a temperature sensor-to measure fluid temps for the blower-plumbed into the case. Dorian also tapped into an outlet on the oil-filter housing and ran a braided line that routed engine oil to another temperature probe. A dual-channel pyrometer was used to monitor each temperature simultaneously when we went for a road test to see if there were differences.
Were there differences, you ask? You bet there were. During our road test, we put our blown 'Stang through roughly an hour of start/stop driving on city streets and steady-speed cruising on the freeway with the occasional "vanishing-point" blast. We shot away from 70-mph traffic at more than 110 mph in an instant-without downshifting-in Fifth gear, through the canyons, and in full-on, four-gear drag runs at the northern end of Canoga Ave, which is an industrial area along a main boulevard in the West San Fernando Valley.
The main thing we noticed in each driving condition was that engine oil, not blower oil, consistently registered a higher temperature on the pyrometer. The temperature difference ranged between 20 and 40 degrees throughout most of the test trip, and the only time we saw signs of temperatures being closer was immediately after our more-aggressive runs.
One of the interesting characteristics of the engine oil was the rate at which it got hot under aggressive driving conditions. With both the engine and supercharger under hard acceleration during our pseudo quarter-mile passes, the engine oil heated up much quicker. We saw an increase from 210 to 230 degrees literally in seconds, while oil in the supercharger slowly maxed out at 198 degrees from an initial temperature of 194 at the launch.
Our findings just about put to bed the speculation that self-contained blowers are basically hot boxes for the oil inside them. But it's important to note we conducted this test to find out the real deal with regard to oil only. Our findings did not have any influence on the actual air-charge temperature-as a rule of thumb, according to ProCharger, for every 10 degrees of oil-temperature reduction, the air-charge temp is only affected by 1-2 degrees-so the oil temps do not have any significant effect on the actual amount of power that can be made with a supercharger.
We didn't know what to expect when we started this evaluation, but we were pleasantly surprised by the results
For our final tests and tuning, we replaced the satin-finish, test supercharger with a high-beam, polished version of the P-1SC. The throttle body/plenum combination adds to the bling quite nicely.
DiabloSport's MAFia unit (PN F7373; $179.00) was employed to help us dial in a great tune for our blown '02. This device basically allows us to control the mass airflow meter by recalibrating its voltage as rpm increases. Dorian locks the MAFia on setting No. 2, which rescales the mass air meter and allows it to let 32 percent more air pass through the meter before pegging it at 5 volts. For example, prior to installing the MAFia, we saw the MAF get pegged (4.9 volts) at 5,300 rpm. But during one of our final dyno pulls after installing the MAFia and calibrating to the No. 2 setting), we recorded 4.7 volts at 6,000 rpm (redline).
Saul "The Surgeon" Gutierrez is Extreme Automotive's resident dyno tuner. Saul specializes in writing and editing custom tunes using DiabloSport's Chipmaster Revolution software, and he was confident we would see impressive power and torque figures at the end of the day.