I have a new to me 98 zj 5.9. I just a put a rebuilt trans in it and it has a flowmaster 50 on it. I'm used to diesel Dodges and Fords that are really fast. This Jeep doesn't seem very powerful from driving it the last few weeks. My dads Denali would smoke it I'm sure. My question is, what kind of things should I be looking at to gain some power? As far as tuning goes, what route should I go? Superchips? Thanks for any input, it really is appreciated.

 

Headers, full mandrel bent 3" exhaust, Cold Ait Intake, Spark plugs, ect.

 

A chip wouldn't do much on these older computers. But ya exhaust and all that

 

Cool. If I was to do a ported intake manifold and throttle body possibly some valve train upgrades in addition to the exhaust u mentioned above, would the computer need to be tuned to accommodate for the improved air flow?

 

If you want to go fast buy a sports car, not a jeep....

 

Nahh, I'd like to have a fast Jeep.....

 

Stroker kit. Or if money is no object, do the LS1 small block 350 swap.

 

Yeah money always seems to be an issue haha. I just can't believe it's so hard to get over 300 hp out of a fairly large v8. Gonna get a locker and new 33 inch mickeys and I won't be so focused on the power issue haha.

 

Any real hp gains are going to cost good money. A TRUE cold air intake, headers, high flow cats, 3" exhaust, and electric fans are the easiest bolt-ons for more hp. If you want to get more in depth then port and polish the heads, intake and exhaust manifolds, and cams.

 

Yeahh, shoulda gotten an XJ haha. This thing doesn't feel much faster than a 4.0 haha ahh well.

 

Instead of a cold air intake, get a snorkel, it'll go through deeper holes like that plus it'll put the intake truly out in the coolest air possible, just a suggestion

 

Exactly.


Does this new to him 5.9 have larger than stock tires? May need to regear the diffs.

 

I have a 5.9 and it scoots. I've done a hotter coil, wires, all copper and brass ignition pieces, a open element intake with a heat shield, full 3'' exhaust from manifold to cat and dual 2.5 back. Also have a superchips hyperpaq, made a small difference after the other upgrades and a 180 t-stat, also allows the shift points to be raised, which helps with my slightly bigger tires. Its no sports car, but it will surprise most 5.0 pusstangs that every 16 year old has mommy buy for them. Mine is a pavement princess and never sees offroad. This summer i'm looking to tear into the valvetrain and try to grab a little more power out of the 5.9.

 

I heard somewhere that the intake manifolds are pretty restrictive. There's a tutorial on how to port them at home to get some added power across the RPM range. Ebay 5.9 magnum intake.

 

I've seen some stuff on that, never looked into though. I'd like to grab a spare manifold at the junkyard before I starting messing with it. I found out a lot about how the motor responds to different things by cruising the Dakota RT forums. There are some differences of course, but its all Magnum information. Worth some research if you're serious about it. Keep me updated on that intake if you go any further on it! Good luck!