Regular readers will recall our original installation and testing article on ProCharger‘s revolutionary i-1 programmable supercharger system. With the ProCharger installed on our 5th Gen Camaro SS, we saw an increase of 172.7 horsepower and 184.8 pound-feet of torque to the tires at only 7.5 pounds of boost, with very conservative ignition timing for safety using California’s so-called “Premium” gasoline.
What makes the i-1 revolutionary is the variable speed transmission incorporated into the supercharger that allows boost curves to be adjusted with precision – a single gear ratio transmission has to be a compromise to provide good boost at low RPM, without overspeeding the centrifugal compressor as the engine reaches its rev limit. With the i-1, the step-up ratio between the crank and the supercharger is computer-controlled and infinitely variable, providing consistent boost across the entire operating range and more power “under the curve” where you can feel it.
While we were very satisfied with the results we got from the standard i-1 system, when ProCharger suggested that we test their upgraded 9 PSI setup, we jumped at the chance. The upgrade was simple – all we needed to do was replace the i-1’s ‘brain’ that controls boost, and upgrade our fuel injectors to keep pace with the higher demand for fuel.
More Air, More Fuel
DeatschWerks Injector Specs
65lb (700cc) Fuel Injectors
Product SKU: 16U-00-0065-8
Fuel Pressure Range: 40-70 PSI
Minimum Pulse Width: 1.0 ms
Maximum Duty Cycle: 93%
Coil Impedance: 12.4 ohm
Injector Type: Bosch EV14 (compact)
Connector Type: us-car
Of course, since they have a higher flow capacity than stock (that’s the whole point), the ECU’s tune must be remapped to compensate, but DeatschWerks makes that as painless as possible, providing complete injector flow rate data for the matched set, as well as battery offset information. All of DeatschWerks injectors are compatible with E85, carry a 3-year comprehensive warranty, and arrive flow-matched and tested.
We enlisted Cunningham Motorsports owner and head mouse-clicker Ryne Cunningham once again to rework our tune for the new boost and injectors, and with the information provided from DeatschWerks and ProCharger, we were up and running on the dyno in no time.
Putting Rubber to the Roller
Strapped down on our Dynojet Research 224xLC chassis dyno, we began to make pulls while Cunningham tweaked the tables on our LS3’s tune. Still running pump gas, and with boost peaking at 9 PSI, we saw a new best of 599.5 horsepower and 619.8 pound-feet of torque to the tires, for an increase of 14.5 horsepower and 18.9 foot-pounds at their respective peaks. Our air/fuel ratio was staying right around our 12.0:1 target, proving the new injectors were doing their job.
What’s far more impressive than just the peak numbers, though, is the comparison of the area “under the curve.” A look at our 7.5 PSI graph compared to the best 9 PSI pull is revealing. Have a look at the dyno chart below, and notice how the red 9 PSI torque line absolutely soars above the blue 7.5 PSI line starting at 2,500 RPM and never looks back.
Back on Track
Dyno pulls are fun and all, but we were anxious to actually make use of the new horsepower. So we put on our drag radials and headed to Auto Club Dragway in Fontana, California for their test & tune. Straight off the street, our first pass showed promise – even with a glacial 2.257 60-foot time, by the eighth mile marker 7.991 seconds later, the Camaro was running 98.38 miles an hour. At the finish line, we clocked an 11.971 second pass with a trap speet of 123.02 MPH. A second pass with an equally dismal 60-foot rewarded us with a 12.077 at 122.01 MPH; clearly, there was a lot more to be found once we figured out the trick to getting our manual-trans car to launch at its full potential.
Finally, with one pass left in the day’s schedule, we got the right combination of launch RPM, clutch slip, and throttle application, and dropped three tenths off the car’s 60-foot with a 1.907. Things were looking very good – at half-track, the car clocked a 7.461 at 99.30, the quickest and fastest we’d seen. Through the finish line, the ProCharged LS3 was pulling hard, but alas, a timing system malfunction robbed us of our full quarter mile time and trap speed!
Nevertheless, based on the back-half track incrementals from our previous runs, we can come up with a pretty good estimation of our final run – 11.34-11.44 seconds. We’d say that once we get the car to really 60-foot like it should, this Camaro will be a solid 11.25 performer at the dragstrip on DOT tires, running pump gas, and with the incredible road and race flexibility that no other supercharger system can match.