Before engaging the NOS wet EFI kit (equipped with 75hp jetting), we retarded the timing by 3 degrees to reduce the chance of detonation. This dropped the power output to 351 hp. Activating the NOS fogger system increased the peak power output to 427 hp at 5,700 rpm, while the torque peak shot up to 468 lb-ft of torque (see the graph for full details). The nitrous improved the peak power output by 68 hp and torque by 87 lb-ft, but the gains were consistently 75 hp or better through the entire rev range (once activated).
Had we elected to run the nitrous clear past 6,000 rpm, we'd have seen an even higher peak-power number. And believe me, you'll notice an extra 75 hp--and especially 87 lb-ft of torque.
Stock 4.6L Three-Valve vs. NOS Nitrous (75hp shot)
As is evident by the power numbers, installation of the NOS wet EFI nitrous system offers a significant increase in power and, more importantly, torque. The 4.6L test motor was equipped with a set of long-tube headers and run without any of the accessories--only an electric water pump--and at a cooler temperature (130 degrees); this is why the motor produced so much more power than the 300hp factory rating. Run in stock trim, the 4.6L motor produced 359 hp and 381 lb-ft of torque. Since we are running the motor on 91-octane pump gas, we elected to retard the timing by 3 degrees before engaging the nitrous. Running a 75hp shot, the NOS kit improved the power output to 427 hp and 468 lb-ft of torque. We made sure the nitrous bottle pressure was at 900 psi for optimum nitrous delivery before making our runs.
Nitrous
Rather than install the full-throttle...
Rather than install the full-throttle activation switch, we simply wired a manual activation switch. This way we could load the motor at full throttle on the dyno before activating the nitrous.
Run on the engine dyno with...
Run on the engine dyno with a set of long-tube headers, the 4.6L produced 360 hp and 387 lb-ft of torque. After adding the 75hp shot, the peak numbers jumped to 427 hp and 468 lb-ft of torque. Had we held down the activation button a tad longer, the peak number would have exceeded 440 hp.