Torque Gains

[ReBeL XJ]

I have purchased an engine from a 90 model. It will be swapped into my 89. I want to know what upgrades i can do to gain some torque. I already have Bocsh(spelling) Platinum 4 plugs, Jacobs Off Road ignition,FIPK, 2.5in exhaust piping to a 3in hi flow cat and flowmaster. what else can i do to gain some torque(without porting) and better gas mileage?

[XJZ]

Your best bet would be an RV-type cam. And I think the mods you've done so far would really compliment the cam. Plus, the cam would probably give you more gain than any one of your other mods. Do a search, there's a ton of discussion on that subject, Good Luck!

[ReBeL XJ]

ya ive been reading other threads and they all talk about doin porting. what is an RV-type cam?

[Dr. Dyno]

I have purchased an engine from a 90 model. It will be swapped into my 89. I want to know what upgrades i can do to gain some torque. I already have Bocsh(spelling) Platinum 4 plugs, Jacobs Off Road ignition,FIPK, 2.5in exhaust piping to a 3in hi flow cat and flowmaster. what else can i do to gain some torque(without porting) and better gas mileage?

You can copy a lot of the mods that I've done to my 4.0. Take a look around my website for ideas. The only differences in your case will be:

1. Mopar Performance computer (if you can still find one and that ain't cheap).
2. You can get a bored HO TB and fit it to your intake manifold using Joe Attardo's adapter plate. There's more info. about that on the "intakes" page of my website.
3. Your non-HO head doesn't flow as well as the HO head out of the box, but porting it will bring it close to the flow of a ported HO head so it's worth doing. You should gain at least 10hp and possibly as much as 15hp.
4. An "RV cam" has a short duration to produce more torque at low rpm. The best cam for low/medium rpm on a 4.0 is the Crane 248/260 degree cam #750501. Cost, together with lifters and springs, is about $350. Installation by a repair shop will cost over $500 because it's a minimum 8 hour job. If you do it yourself with a friend to help you, installation will only cost you a few beers and a pizza.
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Modified (http://www.jeep4.0performance.4mg.com/mods.html) 1992 4.0 XJ Laredo UpCountry, 170k miles, AX15 (http://www.off-road.com/jeep/tech/trans/ax15.html), NP231 (http://www.off-road.com/jeep/tech/xfer/np231.html), D35c rear (http://www.off-road.com/jeep/tech/axle/d35c.html), D30 front (http://www.off-road.com/jeep/tech/axle/d30.html)
Estimated 240hp@5250rpm/280lbft@3500-4000rpm
1/4=15.02@92.9, race weight 3490lb
Future mods: 4.6L stroker
Website: Jeep 4.0 performance (http://www.jeep4.0performance.4mg.com)
Webpages: Electric fan (http://www.angelfire.com/my/fan/electric.html), IAT sensor relocation (http://www.angelfire.com/my/fan/IAT_sensor.html), Intake manifold heatshield (http://www.angelfire.com/my/fan/manifold.html), Oil temp. gauge install (http://www.angelfire.com/my/fan/oiltemp.html), Jeep 4.0 cam specs (http://www.angelfire.com/my/fan/Jeep4.0Camshafts.htm), Jeep engine dyno graphs (http://groups.msn.com/desertxj/dynocharts.msnw), Automotive formulae (http://www.angelfire.com/my/fan/formulae.html), CTS resistor trick (http://www.angelfire.com/my/fan/CTS.html), MAP adjuster (http://www.angelfire.com/my/fan/MAP_adjuster.html)

[AZGOLDXJ]

Try reducing your tail pipe down to 2.25" or even 2.0" because the 3" exhaust will over scavenge and lose your lowend torque. Checkout www.go.jeep-xj.info/ he's worked out the torque related to diameter issue pretty well.
Good luck.