Looking to get more power out of my 99 XJ
 

For bolt on mods you can get the 4 or 12 hole injectors, 62 mm throttle body, an air intake, high flow header, and a 2.5" exhaust with a high flow muffler and cat delete if you don't have inspections where you live. Those mods may get you an extra 25-30 HP, anything beyond that will require a turbo or stroker build.

LS swap it ... or what’s already been mentioned ... or 4.7 stroker .

I've done the 4.0 supercharged with an m90 and turbocharged. Turbo is the way to go. PM me if you want to go that route.

Buy a Grand Cherokee SRT, then the only work you'll have to do is climb inside and push "Start".

But then he would have something that is expensive, unreliable and not as good off-road.

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The kid next door bought an '18 and let me take it out for a romp, as far as smiles per mile it's a freakin winner.

why stop there.,.. just get a trackhawk. trust me.. makes a great tow vehicle :-)

By almost completely stock, what do you mean? What size tire are you running? Do you need to regear?

My 99 has a somewhat decent amount of bolt ons (62mm throttle body, 784 injectors, gibsom header, 2.5" exhaust) and it pulls pretty hard for what it is. It's not fast, but it feels faster than it was when it was actually stock with much less miles. 4.11 gears, a manual trans, and skinny, light weight 33s help too. It will white-smoke 31s if desired...

If you want 250-300 crank horsepower, you'll need headwork at the least. I bet a 4.7 liter with an aluminum head and a 93 octane tune could make that much.

I'd love it if Mopar offered a crate 3.6 Pentastar and a 5-speed auto to put in an XJ. I have that combo in my '11 WK2 and it's great!

i'm not a fan of them either..good friend of mine works at the local dealer and they get constant reliability complaints.

Not sure I agree I owned a '14 srt GC, not a single problem. Only reason I got rid of it was to get a track hawk.. also no problem. And I actually do track mine once in a while. Liked it so much, got my wife a durango srt ... not a single issue other than a blown directional bulb.

My guess is that the complaints are due to people beating the he!! out of them and then not properly maintaining them. There's nothing any more unreliable about them or the trackhawk over the typical GC.