bones21

So my question is are the chips worth the money same if so witch one is the best. Looking to see what is the best power upgrade have a lot done but always want more. I'm not one of trailer xjs ialso pull a 1500 lb pop up so need one good towing any ideas let me know

4.7turboi6

back befor i turbod my xj trail rig i had a bullydog u can go to autozone and pick one up i could tell a bigg diff. in power and tq

XJJeff

I have herd really good things from Hemi Fever Tuning off of dodge talk not much on any Cherokee forums. He is the only person who makes SCT tunes for the 4.0 I6

98xj_john

i got the hypertech econ tuner fs worked good... had st2 jet which was great for 2 wks then ruined my injectors an fouled plugs instantly

jmm0122

Chips and the 4.0 don't go together very well. Waste of money.

Bustedback

X2

93gc40

Best power upgrade for the XJ has nothing to do with the motor. It is installing the correct gearing, so that you can actually access the Torque and HP it already has. It is geared for FUEL economy from the factory, not power. STOP LAUGHING, its true.

Al's92xj

So what gearing would you recomend for 31" tires?

bones21

I'm running 33/10.50/15 with 4.56. I can run down the highway 75 at 2600 no problems. Had 31 when I first did the gears and like they say its a wicked power upgrade. 4.56 is the 4.0 sweet spot.

Countryboy4x4SAO

What about running 35" tires? Would 4.56 still be a good choice?

dogger15

4.10

lolz_jeep

yea but it would all kinda level out and be like stock if u want to get an upgrade with 35's 4.88's would be good or mabye 5.08's

TrollHammer

Is that with a manual or auto trans? I'm debating between 4.10 or 4.56 when I put the 8.8 in. I have stock gears and 34's now and have no problem on steep hill climbs in 4Lo. At 4.10 I only have to buy one gear set. I also have an auto transmission which is geared different than a manual, so I don't know how much Im' cheating.

OnlyInMyXJ22

I don't think anyone makes a 5.08, but either way can't get it for stock Jeep axles. Largest you can run will be 4.88 in both the D35 and 8.25. Can run up to a 4.88 and then jumps to a 5.38 in the D30.

If you want more power with 35's go with 4.88's. If you want better mileage go with 4.10's. If you want a mix of both, close to factory ratio, go with 4.56's.