Spray Pattern: Zex Nitrous System Install

Horse Sense: Nitrous-oxide injectionresults in a dramatic increase in horsepower and torque. Be prepared toaddress other areas of the car because of this performance increase. Theclutch/flywheel, rearend, bottom-end components, suspension, tires, fuelsystem, intake tract, and ignition system might need to be upgradeddepending upon how much nitrous you add to the mix.

Exciting new performance parts continue to pour into the marketplace forAmerica's favorite new car--the '05 Mustang GT. These range from thesimple cold-air intake and power pulleys to more elaborate items such asperformance camshafts, ported cylinder heads, and, of course, poweradders. ZEX has just released its new nitrous-oxide kit speciallydesigned for the latest Mustang, and we've heard some amazingperformance barriers have been crossed with the aid of the new ZEXsystem. Nitrous oxide acts as a fuel-burning enhancer as well as anintake-charge cooling agent. When combined with the correct amount ofadditional fuel, nitrous oxide is an affordable way to dramaticallyincrease the output of any internal combustion engine.

With the promise of more horsepower and the hype the new Mustang isgenerating, we couldn't wait to get our hands on a ZEX kit. This storybegan when Matt Patrick, product manager at ZEX, contacted us withdetails about the new ZEX '05 Mustang GT system [PN 82034; $619.95]. ZEXis the first manufacturer to engineer an application-specific nitrouskit for the new Mustang. The new kit is designed to work with the touchycomputer on the '05, as well as the returnless fuel system. The kit alsoincorporates several performance features this company is known for,such as Active Fuel Control technology that automatically adjustsnitrous fuel enrichment with bottle pressure. On the company's Web site,ZEX boasts "the engine will never run too rich or too lean" with theActive Fuel Control. There's also a patented TPS switch for perfectactivation of the ZEX system and a wide selection of jetting sizes for apower range of 75-175 horses.

For this installation, we also wanted to evaluate several other ZEXproducts that enhance the efficiency of any nitrous system. Theseincluded a ZEX bottle heater (PN 82006; $119.95) so we could preciselycontrol bottle pressure; a bottle-pressure gauge (PN 82005; $43.95) sowe could precisely monitor bottle pressure; and the company's tricklighted purge kit (PN 82270R; $159.95) that's available in a number ofcolors. The nitrous purge is used right before a run to clear the nozzlefeed line of any gaseous nitrous oxide, so when your nitrous system isactivated, you have nothing but raw nitrous oxide hitting the intake.These options enhance the performance and, more importantly, theconsistency of your nitrous system, which will allow for better tuningand repeatability--especially when you're engaged in serious competition.

To test the ZEX nitrous system, we enlisted the help of MD Motorsportsin Cincinnati. The company's owners, Ken Bjonnes and Brandon Alspet, arewell ahead of the average speed shop when it comes to hot-rodding thenew Mustang, and they couldn't wait to have their installation and SCTtuning facility install the ZEX system on our test car. For this story,we left this car in complete as-delivered trim. We knew that JustinBurcham from JPC had run some amazing 10.90s with the ZEX kit, but hehas a car with a few race-car-specific parts some might consider to beconcessions to streetability. So the plan was to install just the ZEXkit to see how it would enhance the performance of an '05 Mustang.

The engineers at ZEX carefully set up their system so the base powerlevels (75hp jetting) would work well with the stock computer tune. Acustom tune-up is required when you go beyond the ZEX kit's 75hp settingbecause increased nitrous injection dramatically alters the programmingmaps in the '05 Mustang computer. To handle this, MD Motorsports usedthe new SCT Datalogger and SCT software to tune our car. The '05 Mustangis equipped with some of the most sophisticated programming theaftermarket has ever faced. The SCT Datalogger was critical in makingsure our air/fuel and timing maps were dead on for this story.

Also keep in mind that the ultimate potential of nitrous (or any poweradder) on the Three-Valve engine is stymied somewhat by Ford's use of aproprietary spark-plug design. We've been told a spark-plug fix is onthe way from the aftermarket, so we'll keep you posted. ZEX recommendsthat you do not proceed past the 125-horse level without some seriousengine work--including forged pistons, steel rods, and a bigger fuelsystem. The fuel/nitrous delivery in this application is a diceyproposition, so ZEX provides a nozzle specific for the '05 Mustang inits kit. The use of other nozzles could be dangerous to your engine'shealth.

Installation time for this kit went a bit longer than the manufacturer'stwo-hour suggestion. This was one of the first times anyone had put akit on a new Mustang, and our our general lack of familiarity with thenew car contributed to the extra time. After years of dropping nitrouskits on 5.0 Mustangs, it was refreshing to have to figure out where allthe nitrous feed lines should be routed.

Stock, our '05 Mustang recorded 257 rear-wheel horsepower and 280 lb-ftof rear-wheel torque--running 93-octane pump gas and the stock tune. Withthe 75-horse jets installed in the ZEX nitrous nozzle, the '05 bangedout 337 hp and 400 lb-ft of torque for a satisfying 80hp and 120-lb-ftgain at the rear wheels. Remember--these numbers are for a car that'scompletely stock (no CAI, mufflers, underdrive pulleys, and so on)except for the ZEX nitrous kit and a dedicated SCT tune of the factorycomputer by MD Motorsports.

Our pictures should provide all the information you need for ahassle-free installation. Once the work was complete, the MD Motorsportsstaff was ready to get our car to the track. At the dragstrip, the ZEXnitrous kit completely transformed our bone-stock five-speed car.Without the spray, our '05 ran a best e.t. of 14.02 seconds in thequarter-mile at 101 mph. On the 75-horse gun, the Mustang galloped rightinto the low-13s with a best e.t. of 13.1 at 107 mph.

DYNO RESULTS