phsycho

I don't know much about aftermarket perfomance suff and was wondering about a few things.
1. If I add a new throttle body, tb spacer, cold air intake and magnaflow cat-back, do I need to get a programer to adjust the settings on the computer?

2. with a 4.5" lift do I need to get a cv shaft?

3. Is it worth replacing axles shafts or should I wait till they break?

4. Stock question. what is the reason for the small plastic piece that is between the air box opening and headlight? Is it to keep dirt/water out? It seems like it would restrict the airflow alot.

n_a_i_w

yes you need a cv shaft with a 4.5 inch lift. as far as axles. what are you going to be doing.? if you no your going to be doing some major wheeling ,do you want to be stranded out in the middle of no where.? if your biulding your diffs. biuld them right. it will save you money in the long run

phsycho

right now I have stock diffs and I don't wheel really hard. mainly 2trax and forest trails. never very far from tow vehicle, and not planning on an extream build.

93gc40

1. A bored TB is a good idea, spacer waste of money, CAI and exhaust Good if done right, Most CAI are gimmick. XJ Computer not really programable from what I understand, they can be flashed, but not programed on the fly.

2. CV at 4.5" is not required, but Highly advised. Any higher, IMO, is a must.

3. Personally, I would invest in a set of Stockers from the JY, to carry as spares. The need here really depends on expected use, and which axle you have.

phsycho

don't know much about the computer...what do you mean by "flashed"?

phsycho

D30/D35

phsycho

Hey its been a while and I never did find out if I need to mess with the computer if I add performance parts. Can anybody help?

EMAXX620

no need. i have swapped injectors to ford ones (better spray pattern)
Have a 63mm TB
http://strokedjeep.com/tbody.html

have an intake and done exhaust.

bit late, check my sig to see if i forgot anything

only thing i can see needing a custom tune is if your build a stroker and want most out of it. Dont waste money on a TB spacer or a chip/programmer

moparguy47

Does upgrading the injectors lower the mpg? Im not positive but Im pretty sure it will make the mpg worse.

EMAXX620

No, not worse. It will make it better due to a better spray pattern. The stock injectors have 1 hole to distribute the fuel, while the "new" ones have 4 holes while they still maintain the same ammount of fuel that is being dumped into the cylinder.

theres plenty of writeups and end results of injector swaps in the cherokee tech section. Most of the people say better idle, better acceleration and possinbly a bit of a power gain, along with better fuel economy.

when i swapped mine i immediatly noticed a much smoother idle. i personally didnt notice any acceleration or power gain. i believe this had part to do with an intake, 63mm throttle body, and free flowing exhaust that i had already on it.

storm101

I second the vote on a bored tb, (check that link out from emaxx, I put mine on last week, hes a great guy with a good products), intake (any way its done, it helps get air in faster, you will at the very least gain pedal response), and of course if youre sucking air in better, you need to get it out better, many options as far as exhaust, do some researching and decide for yourself, the vendor mudfrog on here has some good kits though, just got that installed last night....it all makes a big difference in combination.

The computer should just auto adjust to what youve done as far as any of that, the easy way to make sure is to disconnect the battery, and touch the wires together (pos and neg WHEN DISCONNECTED, and leave em off for a while)

moparguy47

How does it sound? Is it much louder? I just bought that exhaust with the magnaflow muffler I also bought one of those thunderbolt cat's he has. I also just bought the pipe that goes from the manifold to the converter from a local auto parts store. There is a leak at the flange so I thought go all the way and replace it all. Its my everyday driver so I hope its not super loud?

EMAXX620

i dont think its going to be overly loud. of course its going to be more throaty then stock, but not obnoxious. A lot of people around me run no cat (no visual or emission testing here) Ive heard the following setups
1. i-6, no cat, flowmaster 40
2. 5.9, no cat, super 44
3. i-6, no cat, glasspack
4. i-6, no cat, super 44
5. i-6, WITH cat, dynomax tailpipe and muffler (cat looked to be stock one)
6. i-6, WITH cat, flowmaster 40 (again, cat looked stock)

now i know its against the rules to run no cat, but i am just saying what setups i have heard in person. I love how the 5.9 and the i-6 sound with no cat. The 2 with a cat didnt sound bad by no means, just not as deep.

the worse thing ive ever heard (twice) was an i-6 with no exhaust at all.... holly crap is that overly loud. One was mine sadly, cat got ripped off wheeling and was dumping right before where the cat connects into the downpipe. what a drive home that was... The 2nd time i seen a old beat up rusty xj pulling out of a parking lot and gunned it while passing me, kinda hurt the ears haha

Dwinthrup

The pcm will adjust but not as much as you would think but you need good sensors to help it do it's job "o2, map, and the other key sensors" Also don't touch pos and neg together to reset the pcm just leave it unhooked for 5 min or turn the lights on with the battery unhooked.

storm101

as far as the flowmaster muffler he has in the kit, I love it, bit loud on a cold start but not imho obnoxious, I have 2 young kiddos with me all the time, and it doesent bother them either, quite a throaty sound.

and if the method I stated above isn't good, why have I never heard of putting in different sensors? Works just fine for me and a ton of other people on here? The cable tap works just fine, no harm done.