The Testing
All work was done on Kenne Bell's Dynojet. This is a favorite of ours, as Jim's dyno has more instrumentation on it than any other we know. In the cockpit, Kenne Bell technician Brent Morris had a Horiba air/fuel meter, a Fluke digital thermometer, a Toshiba laptop for datalogging, a STAR II tester, the dyno on/off control, a printer for the STAR tester (which was perched in the back seat), a power strip, enough wires and cables to start a phone company, and a clipboard with good, old paper and ink so the dyno and datalogging sheets could be notated and kept together in order. The data sheets were collected into a notebook as they were printed. In the end, more than 250 pages of data were obtained.
Kenne Bell customers will...
Kenne Bell customers will receive their Cobra blowers like this, assembled with the two-hole intake casting, adapter plate, and some small parts such as the pulley. The prototype was polished--the standard finish is a handsome semigloss black.
With the datalogging, horseback analysis, cooldown, and other requirements, each test took about 20 minutes to perform, although some had hours of downtime as a new chip was written or equipment fitted. In all, four long days of dyno time were expended. Though there were some false starts and deadends, there were never any failures. Yes, the test ran long, but given the complexity of instrumenting the test car--there's plenty of drilling and tapping involved in this--once the car was on the dyno, the impetus was to see the test through.
The engine was rigged with numerous probes, many of them for temperature. The stock Eaton blower and intake were removed and replaced so the intercooler/manifold could be drilled and tapped to accept the probes, which were hooked up either to the dyno or the laptop datalogger. This allowed us to see the ambient or blower inlet temperature, the blower outlet temperature, and the intercooler outlet temperature, along with boost and intercooler water temperature. When the Kenne Bell blower went on, it received the same treatment.
Brent had his own electronic...
Brent had his own electronic Toys-R-Us in the cockpit. The STAR tester is in his left hand, the Toshiba is on the passenger seat, the dyno controller is hanging from the rearview mirror. The Horiba air/fuel meter and computer printer are not visible here.
Datalogging was done with a Toshiba 325CDS computer running proprietary Kenne Bell software. This is non-user-friendly, DOS-based software designed by Ken Christley at Kenne Bell. He used to have his own company, and the software dates from those days.
Nearly all testing was done using 100-octane unleaded, bought by the barrel from a local fuel supplier. At the end, as the power levels soared, 2 gallons of 116-octane, leaded race fuel were added.
Finally, all testing was done with the same eight Denso IT22 spark plugs. Kenne Bell is Denso's biggest cheerleader, as Jim's seen the Iridium-tipped plugs run cleanly long after any other plug has given up. Since we knew these plugs would be used in this test eventually, they were installed from the get-go.