Straight Pipes on YJ?

[mudYJ94]

Will straight pipes sound good on my 1994 YJ 4.0, or will it sound like a ricer? and how hard would it be to take my muffler and cat off?

[Pollock]

I think it would sound funny!!! :laugh:

[JeepXLC]

i ran this way on my 89 comanche w/4.0 for a while. it's loud. kind of sounds like a ups truck. personally i liked it. i got better gas mileage and better power at the expense of a little low end torque. not much though. at first i dodn't really know how much power i gained until i put a muffler back on (because i started a job that let out at 11pm and my neighbors didn't appreciate a muffler less 4.0 at midnight). when i put a muffler back on i noticed a little more lower torque but the nizzuts had been cut off of my upper rpm power.

[mudYJ94]

does anyone know what size pipe i will need?

[mudYJ94]

will it be ok if i just use exhaust clamps instead of getting it welded?

[cb89xj]

Are you planning on running 2 pipes back like dual exhaust? Or, one pipe back which would be the right thing to do on an inline engine? Just curious.

[mudYJ94]

just one

[spitfire]

I ran a straight pipe on my YJ with no Cat and it sounded good just when it was idling. When you gave it gas it was too loud and sounded like ****.

[cb89xj]

-=- originally posted by mudYJ94 -=-
just one

Oh, ok...your first post made it sound like you wanted duals on an inline motor. Sorry :D

[mudYJ94]

hey "spitfire" did it sound deep at all when u would give it gas? or did it sound a little ricey. and how loud is loud in your opinion? anyone else that has run exhaust with no cat or muffler on a 4.0 YJ please post your opinion

[Bri]

Ran open headers on a 400ci Ford ... it certainly did NOT sound "good", it was just loud.

[mudYJ94]

will my jeep have a loud, kind of deep popping sound? and how loud will it be on the inside on the highway?

[7SlotGrille]

-=- originally posted by mudYJ94 -=-
will my jeep have a loud, kind of deep popping sound? and how loud will it be on the inside on the highway?

i dont think youll be satisfied until you try it for yourself.

try it for yourself and see how you like it. shy of a sound clip, nobody can tell you how something sounds exactly because its relative.

[92YJ4liter]

wouldn't the motor run bad with out the right back pressure from the Cat? isn't that the purpose of a cat-back exhaust?

[nosduj]

ive got glasspacked sidepipes on my 89 with a 4.0 HO conversion...i love the way it sounds. it is very very loud on the interstate next to those god aweful concrete barriers though...and inside garages. i had no exhaust for about 2 days, it sucked...

[7SlotGrille]

-=- originally posted by 92YJ4liter -=-
wouldn't the motor run bad with out the right back pressure from the Cat? isn't that the purpose of a cat-back exhaust?

its hard to say what the "right" back pressure is for any particular engine. changing the back pressure shifts the torque curve up and down but a 4 liter should be able to run open pipes without sacrificing to much unless youre talking 3" pipe out the back.
that said, i dont know why anyone would run open pipes. if a problem develops in my engine, tranny, or anywhere in my drivetrain id like to be able to hear it before it gets to bad. id also like to be able to talk to my passengers or on a cell phone without screaming. id like to be able to hear my music, my cb, and most important id like to be able to hear anything at all after i switch off.

[spitfire]

Hey mudYJ94, it didn't sound good at all. When I say loud I mean loud. I lived in a small town and my dad was getting complaints from people in town that it was too loud. You can hear me coming down the roas from like at least 3 blocks. I wouldn't recommend doing it. It is up to you though.

Just my 2 cents