I know this is a older post but I love to drive my 97 wrangler. I has all the pep and grunt I need for now. But always seeking to squeeze out a bit more. It keeps up with any stock 4.0L on the trail and on the freeway. I am not boosting, but just exicted I finally got it to the point its at. I would like to share my mods. First I do only run 31in BFG Muds, for now. Engine mods Home brewed cold/ram air intake with modified factory box with a K&N filter. Air is ram in thru the right head light, with bezel removed. Also air is sucked in from the bottom side of air box, with a small cone shape funnel cut thru fender well right above the shock. No it does not suck in any water or get any more dirt above average. The top of the shock mount acts as a shield. Ran a straight air tube to throttle body wraped in reflective insulated heat wrap which keeps incoming air cool. Bored out throttle body. Top side 60mm, bottom side 52mm. This keeps incoming air under presure. Custom made throttle body spacer with air pressure/velocity air blades also helps keep incoming air presurized. It is also taped at 60mm on top and down to 55mm on bottom side. It is my favorite mod, it out performed other throttle bodys. Remember your engine can only ingest certain amounts of air. I learned thru trail and error that if to much air comes in with no pressure my jeep takes off really fast but loses all torque and top speed. You do need to suck in more air but it needs to stay under pressure. I also run a accel coil which is rated at 48,000 volts, accel 8mm coils, NGK plugs gapped at .038. Stock fan niped and tucked and drilled out blades for lighter and less resistance and quicker windups. Dangerous mod not to go beyond point of no return, such as losing CFM or structaul rigidity. Magnaflow muffler, Cut of end of tail pipe downward elbow and installed a stainless steel tip for straight thru flow, works great. Does not look getto. I also run factory bumpers that are cut short with tapered angles for clearance and wieght reduction and less wind drag. I am considering a electric fan. O yeah I did add a poser stinger to my front bumper, very light and study. For looks only, made of old bunk bed light tubing and coated with bed liner. Strong enough to hold highlift jack. Eiether way she is light, fast and nimble. Next on to do list is under carraige skid plating. O I am looking in making my own aluminum rock sliders with replaceble parts. I like my lil frankenstien. Happy Wheeling.
