exaust advice

im hoping someon can help me out or give me a few suggestions.

i have a 93 jeepYJ 4cyl 2.5L done a few cosmetic mods (5"lift 32" tires chrome bumpers etc...) but its time to get the engine runnig smoother , cleaner and give it alittle more kick.

i know i need a new exaust sytem right from the manifold to the muffler, but ill probably replace it right to the tail anyways. should i replace the exaust manifold too? would i gain anything significant by doing so?

any suggestions on which exaust to go with, nothing rediculous but im not replacing wiht OEM but don't wan to go broke either.

alli want: more performance, nice sound, clean look.

please help and make any siggestions!

thanks in advance!!

you probablly dont want to spend to much money on that

so do your own custom exhaust system
start with header/no cat/2.75 line & flowmaster dual chamber
it cost you less than 5-600$ and easy to do with 5'' of lift

i do it with my 4.0 cherokee it cost a bit more for the header but it sound great

but is not give you the extra power you need to roll your 32''

for that you have to change your gear for maybe 4.10 or 4.56 if your not doing too much road

if your jeep is manual, you probably already have 4.10 gears. If auto (like mine), you would have 3.73.

best option in that case is still to re-gear, you can always put intake/exhaust/whatever on the 2.5, it'll help a bit but you won't see much gain unless you put on a SC, or swap it for a 4.0 (they go for pretty cheap sometimes..)

I would re-gear for 4.56 or 4.88 if you plan on putting bigger tires at some point, or go off-road with it. 4.27 would be the closest to your stock performance, but with the added inertia and mass of bigger tires you would want even more power.

usefull chart for gearing :
Gear vs tire chart

I'm running 35" tires on a 2.5l auto with 3.73 gears, can't go faster than 115kph, but it's not that bad... When I'll swap the rear diff I'll re-gear to 4.88 or 5.12.

If the manifold works fine I would leave it alone.

sector said:

I'm running 35" tires on a 2.5l auto with 3.73 gears, can't go faster than 115kph, but it's not that bad...

Click to expand...

Man, I thought my I6 3.07 with 32" is bad. :run:

need.... d44....

thanks for the advice ill look into these things...
yes mine is a manual, but the probel for me is its my daily driver right now (besides my old honda scooter :bigup: so i don;t want to play too much wiht gearing at the moment. i do plan to replace both diff with lockers but thats not in the priority list. im somewaht worried abour running straight pipes just cuz i don't want to burn eaust valves mine are already a little ont he weak side. but i guess that depends on how much backpressure ill have.

i think i may just go wiht something basic for now little nicer for stock till it comes time to replace the engine im gonna rebuild one hopefully next winter boared out oversized piston then ill put on a nice set of headers.

would it pose a problem if i keep stock manifold put slightly larger diameter pipe from the manifole tot he end?

again thanks for the advice im still sorta new at this

its not a problem at all to fit bigger exhaust
but maybe you have to do a new flange to fit with your manifold
or just cut the old one grind it a bit to oversize and weld it to the new exhaust