RPM TQ HP
3,100 443.2 261.2
3,300 439.4 276.1
3,500 426.0 283.9
3,700 417.7 294.3
3,900 548.8 407.5
4,100 571.0 445.8
4,300 558.8 457.5
4,500 563.8 483.1
4,700 561.1 502.1
4,900 544.1 507.6
5,100 533.5 518.1
5,300 525.6 530.4
5,500 509.9 534.0

Results: +117 hp, +114.7 lb-ft

“…it would put most muscle cars with decent suspension in the 9s on sauce while still being a perfectly reliable stock engine that returned respectable fuel economy…”

125HP Shot Dyno Test

Everything looked fine on the 75hp shot, so next we upped the “pill” to 125 hp. Things were working well on our high-mileage truck motor, so we stayed with the 91-octane fuel to simulate what the average street guy would be running. This size shot with pump gas would be an ideal combo for someone running this on the street every day. With the same 23 degrees of total timing and the same 10.8:1 air/fuel ratio, we were up over 200 hp from our baseline naturally aspirated run.

6.0L LS LQ4
125HP Nitrous

RPM TQ HP
3,100 446.1 263.3
3,300 451.0 283.4
3,500 442.3 294.8
3,700 449.9 317.0
3,900 598.2 444.2
4,100 645.8 504.1
4,300 651.0 533.0
4,500 652.6 559.2
4,700 646.5 578.6
4,900 634.7 592.2
5,100 620.1 602.2
5,300 605.4 610.9
5,500 593.9 621.9

Results: +204.9 hp, +203.5 lb-ft

175HP Shot Dyno Test

The ZEX LSX direct-port system uses a unique dual-stage jetting system; there is a set of jets in each of the distribution blocks and a second set of jets in each of the nitrous nozzles that allows the tuner to further trim nitrous and fuel for individual cylinders. The correct combination of jets is listed on the tune-up in the instruction manual. For our 175hp run, we stepped up to VP Racing’s VP100 and pushed the rpm just a little harder. The timing remained at 23 degrees total with the air/fuel ratio at 10.8:1.

6.0L LS LQ4 175HP Nitrous, VP100 Fuel

RPM TQ HP
3,100 444.1 262.1
3,300 448.7 281.9
3,500 452.4 301.5
3,700 465.4 327.9
3,900 640.7 475.8
4,100 707.4 552.2
4,300 703.2 575.7
4,500 707.4 606.1
4,700 696.5 623.3
4,900 691.0 644.7
5,100 674.4 654.9
5,300 658.9 664.9
5,500 639.5 669.7
5,700 624.4 677.7
5,800 620.1 684.8

Results: +267.8hp, +258.3lb-ft

“…the ZEX nitrous system over-delivered on the promised horsepower and torque on every test we ran.”

Where The Money Went
Description: Source: PN: Cost:
Direct-port fogger nitrous system ZEX 82032 $1,329.95
Salvage yard LQ4 truck engine $900.00
LSXR intake manifold FAST 146302 $953.95
Billet fuel rails FAST 146032-KIT $190.95
60-lb/hr injectors (8) FAST 306008 $513.95
92mm Big Mouth throttle body FAST 54095 $476.95
Total: $4,365.75

200HP Shot Dyno Test