At this level, reading every plug is critical to ensuring the tune and fuel are supporting the nitrous you’re injecting. Ours looked perfect after each pull. To step up to 200 hp, we poured in VP Racing Fuel MS109, swapped to plugs two heat ranges cooler than stock. Macy pulled the total timing down to 20 degrees and leaned the air/fuel ratio to 12:1. We actually ran this test twice, producing consistent numbers, but a touch of flutter at the top end and visible flame from the headers told us we were basically blowing out the spark despite squeezing the gap down to .030 inch. Our LQ4 was maxed out in this form.

6.0L LS LQ4
200HP Nitrous, VP MS109 Fuel

RPM TQ HP
3,100 449.5 265.3
3,300 456.6 286.9
3,500 457.5 304.9
3,700 462.5 325.8
3,900 610.2 453.1
4,100 801.6 625.8
4,300 790.6 647.3
4,500 781.5 669.6
4,700 772.1 691.0
4,900 755.8 705.1
5,100 740.9 719.5
5,300 724.0 730.6
5,500 701.9 735.0
5,700 675.2 732.8
5,800 667.0 735.9

Results: +318.9hp, +352.5lb-ft

SOURCE
RPM Performance
928-854-1160
FAST
3400 Democrat Road
Memphis
TN  38118
877-334-8355
http://www.fuelairspark.com
EFI University
39252 Winchester Rd. #107-293
Murrieta
CA  92563
866-316-7744
www.efi101.com
Horsepower Connection
360-280-6112
www.HorsepowerConnection.com
Zex
3418 Democrat Road
Memphis
TN  38118
888-817-1008
http://www.zex.com
Pro Marine Engines & Dyno
928-505-3966
www.PerformanceMarineEngines.com
VP Racing Fuels
P.O. Box 47878
San Antonio
TX  78265
210-635-7744
http://www.vpracingfuels.com