Kenne Bell
Kenne Bell is a huge name in the Mustang world with supercharging and brings that experience to the Jeep market. With three available boost levels (5.5, 8.5, and 15 psi) offering up to a whopping 72 percent increase in torque over stock, the normal 50-state-legal kit provides gains of 47 percent more horsepower and 52 percent more torque. With many available add-ons such as intercoolers, pulleys, and bigger available superchargers, if you like tuning your engine, this kit is for you. Information: Kenne Bell; 909/941-6646, www.kennebell.net
Supercharger Pros
While they don't have a specific application for Jeep vehicles, if you aren't afraid of some accessory bracket modification or fabrication, this company can get you heading in the right direction with its high-quality new or remanufactured superchargers and knowledgeable technical assistance to make sure you get the correct supercharger for your application. Information: Supercharger Pros; 800/779-9876, www.superchargerpros.com
Think Performance!
The Think! Performance Stampede supercharger system is designed with "real world" usage in mind. Kits are available for '97-'06 TJs with the 4.0L six-cylinder, and the emphasis is on substantial torque and horsepower gains in the rpm range that a Jeep is actually operated within. There are no electrical connections needed for ease of installation yet the kit still provides a 50 percent increase in both horsepower and torque. Information: Think Performance!; 877/811-3120, www.think-performance.com
XJ-Armor
As the name implies, the supercharger kit from XJ Armor is intended for XJs-'91-'01 XJs, to be exact. This kit bolts the supercharger on in place of the AC compressor, and, as such, uses the stock serpentine belt while cranking out approximately 100 more horsepower from your XJ. The best part of this kit is the entrance fee of only $2,200. Information: XJ-Armor; 650/365-3335, www.xj-armor.com
Turbochargers
A turbocharger compresses the gas going into an engine in a similar fashion to a supercharger. The major difference between the two is that while a supercharger is driven off the crank of the engine mechanically, the turbo is driven with the exhaust gasses coming out of the engine. When sized appropriately for the displacement of engine and range of rpm the engine operates in, there is very little (if any) turbo lag that can be detected.
505 Performance
If you've got a 4.0L six-cylinder Wrangler, this company has the turbo kit for you. In our testing on a '99 TJ, we saw a rear-wheel horsepower increase of 65, while the torque gains of 90 lb-ft at the rear wheels really made a huge difference in driveability. The kit includes everything you need to start enjoying your Wrangler again. Information: 505 Performance; 505/333-2600, www.505performance.com
Turbocharger Pros
If you drive a Jeep that isn't the 4.0L Wrangler, look to Turbocharger Pros for high-quality new and remanufactured turbos. Sure, there will be some exhaust modifications and intake rerouting, but if you want a turbo, break out the fabrication tools and give the expert staff at Turbocharger Pros a call. Information: Turbocharger Pros; 800/923-0413, www.turbochargerpros.com
NOS
Nitrous oxide-aka dinitrogen oxide, aka nitrous-gets a bad reputation for blowing up engines. The fact of the matter is that by injecting nitrous into the intake, you are adding more oxygen to the mixture. Add too much to it and the engine will quickly be making more power than it can physically handle. Possibly the biggest benefit of nitrous is that it's not always on. If you need a boost for a mud hole or hillclimb, hit it. But you aren't penalized daily when it comes to fuel mileage because you're not constantly burning more fuel. Plus, if you've got enough power day to day, then for under a grand you can get a decent nitrous system.
NOS
The biggest name in nitrous is NOS. While they might not have a bolt-on kit for your Jeep, it's guaranteed they've got something that will work with whatever engine you've got under the hood. From 50-200-plus engine-exploding ponies, NOS has it. Information: Holley; 270/782-2900, www.holley.com
Edelbrock
If there is a name in carburetors, its most likely a name in nitrous too, and Edelbrock is no exception to that rule. From the Performer nitrous system to the Progressive nitrous controller, which both provide control of the funny gas over a period of time through modulation of the electronic solenoid, whatever your need, if you can perform fabrication work one step above duct tape, you can install one of these kits. Information: Edelbrock; 310/781-2222, www.edelbrock.com
NX
Nitrous Express...when you've absolutely got to have that power kick, but you have smashed your little brother's piggy bank for gas money already, NX has a low-cost kit for you. Sure, you'll have to work a way out to feed extra fuel in and possibly fabricate a few brackets, but when is the last time even a bolt-on part really did bolt on? Information: Nitrous Express Inc.; 940/767-7694, www.nitrousexpress.com
ZEX
If you've been looking for a nitrous system to add to your fuel-injected Jeep, look no further than ZEX. With both wet (fuel added with nitrous system) and dry (more fuel pumped through injectors) kits for a vast variety of four-, six-, and eight-cylinder engines-as well as specific applications-this is the fuel-injected nitrous for you. The secret is the Nitrous Management Unit that adds fuel when the nitrous is in use. Information: ZEX Performance Products; 888/817-1008, www.zex.com