Hey Guys,
I'm new here, and somewhat new to my cherokee
I have a '96 cherokee XJ sport 4.0L and I am looking to add some bold on horse power.
Any suggestions for headers and exhaust systems? What will get me the most bang for my buck? I live in CA so it has to be smog legal...
Thanks

 

Well, if you have to have it smog legal, gimme some time to find some CARB cert. stuff...
PM if you're wondering or have a Q...

 

few things that come to mind 99+ Intake manifold and a ported TB,Cold air kit....then exhaust if you dont mind the extra noise...I bought my aftermarket header from E-bay The quality was amazing and it had a lifetime....only cost me 100. You can search under my username for my thread about it.

 

by "99+ intake" I'm assuming you mean intake manifold from 1999 or later 4.0, should I use an OEM replacement or an aftermarket performance manifold? Also, is there a specific throttle body, or just one of the generic 62mm tb's on ebay. I already have a cold air intake. Thanks for the input on the $100 ebay header-

 

Well one thing you can do, maybe not a power adder, but it can help your 4.0L make every horse it should. Do a complete tune-up including spark plugs, plug wires, distributor cap and rotor, fuel filter. Sometimes it's surprising how much more power you can get out of a 4.0 once it's been freshened up a bit. Then you could build an intake for yourself with parts available at your local parts store, using a section of intake tube that you can drill and tap for the hoses running to your intake, and some hose clamps. Then slap a decent cone filter on the end and call it done. You could even take this another step further and build a box for the filter out of some kind of insulated material that's safe under your hood that would isolate it from underhood temps. And widen the dismally small opening behind the headlight that the factory intake draws from. That would provide your 4.0 with a nice cool charge of air!

 

quick question for jeep jeep: looks like that ebay header was for a grand cherokee, will that fit my XJ?
Thanks

 

The throttle body mod is here http://www.strokedjeep.com/tbody.html ...Tj

 

bigger throttle body, hi-flow cat, and a better muffler. also up the size of the pipe to 2.5" from the cat back. stock airbox flows more than enough air to these motors. or your could just go ***** out and do force injection.

 

Look in the XJ Write-ups section for "Homebrew Cold Air Intake". It's a very inexpensive way to build one. It does not alter any swog equipment. You will definitely feel the power difference in the seat of your pants and when you fill up less often.

 

the bored TB was by far the biggest gain on the butt-dyno out of evry single bolt on mod I've done. And it was the quickest and easiest to do. That and a hi-flow muffler (NOT flowmaster... what an oxymoronic name..) will yield the best results IMO.

 

Header - got mine off Ebay
Exhaust/High flow cat with a new front pipe
Bigger TB
and some kind of aftermarket Filter/intake
..........everything else is a waste of money.....

 

http://cgi.ebay.com/ebaymotors/JEEP-...1%7C240%3A1308

That is where i got mine you can see that it is bigger than the stock header and very much improved in design....And has a lifetime. I however did not use the intake/exhaust gasket that came with the kit...i used a felpro. If i would have know about the 99+ 4.0 OE manifolds and how much better they flow i would have put one on at the same time.....OOH well My next engine plans are the I/M and a Ported TB from Strokedjeep.com

 

agreed, even after having my flowmaster for 3 months- im tired of it, looking to throw a magnaflow or something on there

 

Yeah, wouldn't want to recommend Flowmasters. Those things have never been known to be a high flow or high performance muffler.......There aren't ANY guys in the worlds of off road racing or hot rodding that would ever want to use a Flowmaster product.......

 

I've had my jeep for over 8 years and had multiple mufflers...
Flowmaster: Sounded the best but rusted a hole in it quickly
Dynomax: was god awful
Current is Magnaflow: Sounds ok but is more quieter than the Flow..

Muffler choice is really PERSONAL Opinion........