The factory cam is puny. there, we said it. Just a simple cam swap can really bring up the torque, power, and drivability of even a stock Jeep. to prove our point, we searched out a dog of an '89 XJ with the factory remix injection, over 130,000 miles on the clock, and its full complement of factory widgets and smog gizmos. all we did was plop in a Comp Cams Xtreme 4x4 flat tappet cam in place of the factory jobbie. the Comp Cams pn 68-232-4 that we used is intended for stock-type injected applications. with an advertised duration of 250/256 degrees and lift of .460/.476, it's civilized to be sure. But it woke up our stocker to the tune of 12 hp and 18 lb-ft. not bad for an investment of a couple hundred bucks.
Vehicle Specs:
1989 XJ Cherokee
4.0L
AW4 Auto Transmission
3.55 Gears
28-Inch Tires
Power Gains:
Stock: 93 Hp, 147 Lb-Ft*
Modified: 105 Hp, 165 Lb-Ft*
*Note - Numbers Taken At Rear Tires
Sources:
Comp Cams
800/999-0853
compcams.com
Westech Performance
951/685-4767
westechperformance.com
Bolt-On Hp
July 2007, P. 44
Centrifugal Booster
Power Play Combo: Adventure Innovations 4.0L Supercharger System
Some time ago, Cappa flew out to shoot the install of a then-new supercharger system for the Jeep 4.0l. the company, adventure innovations, now has intercooled centrifugal supercharger systems for the Jeep 3.8l, but we shot the company's system for the good old 4.0L.
The adventure innovations unit mounts the centrifugal blower on the passenger side of the accessory drive and relocates the alternator down and out of the way. the factory air box is removed to make way for the intercooler and new air intake. the factory in-tank fuel pump and pressure regulator stay in place, but an additional pump and boost-referenced regulator are mounted to the passenger fender under the hood to augment the fuel supply. in addition to all the hardware, a calibrated unichip is programmed to combat detonation under the unit's designed 5-6psi boost and piggybacks on the factory ECU.
Sources:
Adventure Innovations
805/322-7001
adventure-innovations.com
Vehicle Specs:
2005 TJ Wrangler Unlimited Rubicon
4.0L
Nv3550 Transmission
4.10 Gears
33-Inch Tires
Power Gains:
Stock: 129 Hp, 159 Lb-Ft*
Modified: 202 Hp, 227 Lb-Ft*
*Note - Numbers Taken At Rear Tires