need help deciding on parts

do throttle body spacers work on the 4.0?I pull a camp trlr and would like a little power.also what works for exhaust on these engines for power?

Sure, there's a 'little' seat-dyno affect to them. If you're really interested, there's a ton of info around to be found. I'll start ya off with a goodie... :wink:

http://www.jeep4.0performance.4mg.com/

This is Dino's site. Sift, digest, sift s'more! LOL The guy is a genious.

~Good Luck! Let me know if you need more...

JP magazine covered a turbocharger install...

http://www.jpmagazine.com/techarticles/engine/154_0508_jeep_4_0l_turbo/index.html

Pretty good article. Different jeep, but same engine.

JP magazine covered a turbocharger install...

http://www.jpmagazine.com/techarticles/engine/154_0508_jeep_4_0l_turbo/index.html

Pretty good article. Different jeep, but same engine.
Oh, hell no. I'll be bookmarking this for myself... Thankyou Very much! :iceslolan

If you have the newer "High Output" 4.0 the intake manifold has been redesigned essentially negating the need for the spacer. But, if you think it's worth a shot go for it. Me, I'd rather spend the money on other things. And if you do get one, don't pay extra for one with the "vortex screw swirls" machined into the side of it.... pure snake oil. The 4.0 is port fuel injected so it makes no difference how turbulent or swirled the incoming air charge is....not that those "threads" would do much of anything other than create air flow resistence.

I have a DynoMax catback with their Turbo muffler on my XJ. It's a well-made, reasonably priced kit with a welded on stainless steel exhaust tip.The unit flows very well and the sound level inside is muted and it makes a nice burble at the exhuast tip. A louder muffler can make some serious resonances *inside* your ride making it uncomfortable. IMHO, US-made OHV inline sixes just don't sound very good with loud mufflers.

The stock engine is built for longevity and durability. It's a low stress motor that will last, with a modicum of care, upwards of 200K before a serious rebuild is needed. Unless your tastes run expensive (as in stroking the engine, aftermarket turbo/supercharger kits) you're not going to improve much on the basic design...especially the newer H.O. 4.0L.

The swoopy "performance" intakes will lighten your wallet to the tune of about 300 smackers and make your jeep louder.....if you wanna try one, Google up one of the home built units posted on some of the other Jeep forums. "Performance" chips are another huge waste of moolah. Be careful also of the "big bore" throttle bodies, the newer XJ's rely on a vacuum signal from the TB to feed to the transmission computer (which on newer XJ's is combined with the engine computer as one unit). You screw up that vacuum signal and your tranny will ooze it's way through the gears. I know cause I tried it on my Jeep, a 2000 Sport. If you have an older XJ or one with a manual tranny, the big TB's can add some extra oomph at the higer speeds....plus they will sometimes whistle a little which makes it sound as if you've got a turbo under the hood.... high scale readings on the "cool-o-meter".

One of the best ways to up the HP is to give the old gal a decent tune up. Plugs, wires (if you have them), cap and rotor (if you have them). Clean the throttle body, get the injectors professionally cleaned, clean the Crank Case Vent system (the two plastic elbows on top of the valve cover), replace the air filter. Check all your rubber vacuum lines and connections looking for suspect air leaks or rotting hoses.


Mike
00XJ

Mike00XJ

Nice quote. That you? :licka: