bmrrwolfe

So i have a 2000 4.0 cherokee it wasn't to slow but after the lift and bigger tires i wanted to add some power to it. I got a Edge Trailjammer kit and got a little bit more power, but still would like more.
whats the best power adding mod while maintaining a lower budget?
Catback system? electric fan conversion? etc?
Thanks!

mike37

the only thing that is going to help is gears
the est of that stuff is worthless until you get it geared right

okcjeeper

gears would be on top of my list. Also a bored out throttle body will give a but more throttle response but not just how much power.

a1racer

gears if you want it like it was do the gearing stop throwing money at parts that are not needed you will be happier saving that money and doing the gears

broncofire75

Only thing that will make a noticable difference on a stock 4.0 is forced induction.

Stroker works too lol.

But I tried to do the same thing as you and tried to compensate for the heavier tires and get away with not regearing. But that didn't last long.

You might add a few horses and .02 of a MPG if you add a cat-back or another fan but it's useless without the right gearing.

TrekkerJmm

How about getting the throttle body bored out from Leigh Performance Machine
its supposed to help with the low end horsepower...Tj

bmrrwolfe

Already got the bored out throttle body with my Edge performance kit.

What would be the best all around gearing setup? for street and highway pushing 32" tires?
2000 automatic with chrysler 8.25 rear i think its 3.55s right now?

okcjeeper

4.56's but if you plan on going bigger maybe even 4.88's...

MasterShakeXJ

stay away from tb spacers, from what i've heard theyre essentially just paper weights

solderjunkie

pencil holders!

93gc40

While I agree the first step would be gears. I also agree that the only way you are really going to improve the power of the 4.0 is to stoke it or blow/turbo it.

Is this rig DD or Trail biased? Is your goal FAST or Quick? The 3.55's will be FASTER top speed, lower gearing will be QUICKER, acceleration. If it is to be DD I would go with 4.10 gears, if mainly a trail rig go ahead a go lower 4.56 or 4.88.

tkdtim

Would changing gearing help with more power in the 60-80 mph range?

01LimitedXJ

You re-gear to bring you back into the power band. 4.56 gears with 33's is a slightly deeper gear setup than stock. So you will get slightly better acceleration, but you will run at a bit higher rpm at highway speeds (not much higher).

jrhxj1

Gears are the way to go. Go slightly lower than what you need now for your current tires. Because we all know how the "go bigger" bug bites!

I'd go 4.56. With stock axles, the largest you would want to run would be a 33 or 34. Been there done that. That gear combo will work out great for you even now with 32's. Acceleration will dramatically increase, fuel economy will be a lot better also. At top speeds, you'll pull around 2300 Rpm in overdrive at 65 mph. Actually your speedometer will read 75, speaking of; you may want to get the correct speedo gear while your'e at it. The only other needed concern is the tranny cooling source. Not that huge of a deal if you have the tow package ( tranny has own external cooler). You'll spend about 400 to $450 on gears ( go Superior), and probably about the same for instalation cost, but it will be the best money you could spend! I know from experience! Enjoy your new Jeep-rod!