Vehicle Specs:
1999 XJ sport
4.6L
aw4 auto transmission
4.88 gears
33-inch tires
Power Gains:
stock: 152 hp, 200 lb-ft*
Modified: 172 hp, 224 lb-ft*
*Note - numbers taken at rear tires right around the 10,000-mile mark-after swapping from our 4.0l to the 4.6l engine-we lost a few lobes on the camshaft. during the subsequent
The Insane InLine Update
August 2006, P. 64
Full-Mambo Dyno Tune
Power Play Combo:
Golen Engine Service 4.6l Long Block
Banks Torque Tube
Dyno Shop Chassis Dyno Tune With
Unichip Controller
Right around the 10,000-mile mark-after swapping from our 4.0l to the 4.6l engine-we lost a few lobes on the camshaft. during the subsequent cam replacement, we noted that the header had cracked, so we installed a new Banks torquetube and took our 4.6l back to the dyno shop to have the crew professionally dial in the air/fuel ratios under simulated driving conditions on the chassis dyno. Dyno tuning is both an art and a science and is the only real way to ensure the best driveability under any load condition. the dyno shop used a unichip piggybacked onto the stock eCu to properly manipulate the ignition and fuel tables. since we installed a different header we had the dyno shop establish a new baseline for our stroker combo. The horsepower remained the same, but we saw a 5 lb-ft improvement with the Banks torquetube. in addition to the higher power numbers, dyno tuning offers far superior seat of the pants driving impressions since power across the entire rpm band is increased, as well as throttle performance.
Vehicle Specs:
1999 XJ sport
4.6L
AW4 auto transmission
4.88 gears
33-inch tires
Power Gains:
stock: 172 hp, 229 lb-ft*
Modified: 184 hp, 235 lb-ft*
*Note - numbers taken at rear tires
Sources:
Accel
888/Mr-GasKet X999
mrgasket.com
Banks
800/601-8072
bankspower.com
The Dyno Shop
619/562-3933
thedynoshop.com
Golen Engine Service
800/591-9171
golenengineservice.com
K&N Engineering
800/858-3333
knfilters.com
Performance Distributors
901/396-5782
performancedistributors.com
Rubicon Express
866/523-7710
rubiconexpress.com
Unichip
www.unichip.us
75 Hp In 75 Minutes
November 2005, P. 90
Nitrous!
Power Play Combo:
Golen Engine Service 4.6l Long Block
Nos Powerfogger Kit, PN
05130nos
Nitrous oxide is one of the hardest-hitting power adders out there. Asking no quarter and leaving no mercy, it shoots massive quantities of oxygen molecules into the engine, allowing proportionately massive quantities of fuel to be burned. The results are immediate, but if you don't follow certain protocols, so too can be the consequences. Follow the system's installation instructions and make sure to pull back the timing 2-3 degrees for each 50-75 hp of spray to prevent detonation. run premium fuel (you may even want some octane boost) and check your air/fuel ratios with a meter if possible. we installed an nos powerFogger kit, pn 05130nos on our XJ's 4.6l stroker early in the engine's life to see what sort of power we could make on the bottle. we dialed the system in for a 75hp shot and hit the dyno shop to see what the results would be.
Sources:
The Dyno Shop
619/562-3933
thedynoshop.com
Golen Engine Service
800/591-9171
golenengineservice.com
Nitrous Oxide Systems (Nos)
A Division Of Holley 270/781-9741 (Tech)
800/Holley-1 (Nearest Dealer)
nosnitrous.com
Vehicle Specs:
1999 XJ sport
4.6L
aw4 auto transmission
4.88 gears
33-inch tires
Power Gains:
stock: 184 hp, 235 lb-ft*
Modified: 245 hp, 372 lb-ft*
*Note - numbers taken at rear tires
Cam It!
July 2006, P. 46
4.0L Cam Upgrade
Power Play Combo:
Comp Cams Xtreme 4x4 Cam, PN 68-232-4
For most average Jeep enthusiasts, a cam swap seems like a daunting undertaking. Most are content to slap part after part on the outside of their engines, but few seem to want to crack into the greasy innards to get at the heart of the beast.