will no mufflers hurt performance if i have pipes out the back

dastang2

Active Member
Dec 11, 2003
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hello i have a 95 with true duals. the mufflers fell off and i am having problems with no power but am not sure if it is because of the mufflers being gone or not. i don't see how it doesn't have enough back pressure since it has 4 cats. this car is a piece of junk so there may be other stuff wrong and causing the huge power loss i have been experiencing for over 5 months. what if i just ran connected the tailpipes to the cats and have no mufflers out the back, would that help the backpressure or would i be better off putting some mufflers on. i have 2 old 50 series flows, but i don't want any kind of crappy sound, i have not heard a v6 with 2 50 series without an h pipe. i want to hear one like that. i also have 2 turbo mufflers i can put on there.
 
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i forgot to ask if i did use no mufflers, how would it sound inside, i don't like it as much now since the pipes broke off right in front of the front seats and everything rattles. if i had the pipes extended to the rear, i probably wouldn't do it.
 
like how much slower do you all suspect i would be going. i mean i can drop 2 gears and it barely even starts to pass people around 3500 rpm's. give or take a couple hundred. it won't get 2nd gear scratches easily and barely spins out of the launch. i am getting an o2 code from the drivers side header sensor, put it worked when i put it in. i really don't think that is the full problem if it is the problem though. i want to switch the o2 sensor with another sensor on the car and see if the code switches to another o2 code soon.
 
Do not, I reapeat, DO NOT run with no mufflers. I bought my stang from a guy that ran with no mufflers and later I found out I bought the car with a blown head gasket. The mufflers make backpressure which has something to do with the engine reaching optimal temperature. Anyways, moral is: always use a cond...er...muffler.
 
Your engine has to have something to push against (thus backpressure) in order to make torque efficiently. If you remove that backpressure, you lose the help you need. You can have too much backpressure, but a dual exhaust system on our cars seems to be your best bet as long as you have decent mufflers and at least 2 cats.
 
i forgot about this thread. i went ahead and put the 50 series on the car and it sounded like a foreign exotic car in a way. not bad at all. it did get some power back and i did fix all the other problems with the car. but that was ages ago. i traded that junker straight up for a 95 maxima and never looked back. more power and more mpg.
 
Jamez said:
Your engine has to have something to push against (thus backpressure) in order to make torque efficiently. If you remove that backpressure, you lose the help you need. You can have too much backpressure, but a dual exhaust system on our cars seems to be your best bet as long as you have decent mufflers and at least 2 cats.


ok guys this is going to be one fun post

your engine has to push against somethingto make torque though you say correct?
what do you think the car is doing when trying to spin anyway? it's pushing against the weight of the car. but lets follow your idea of making torque

put big bertha in the car. she will create more torque cause your motor has to push against her now.

install 2.5x gears in your car. that will really help torque production.
install your motor in a van. that way the faster you go the harder it would be for the van to cut through the air. aerodynamic drag induced torque has a nice ring to it doesn't it.

install small heads on the car. the force of the engine trying to push the exhuast out of the exhaust ports will make loads of torque


do any of these make sense? if not then that's good. it's along the same lines of saying ok lets add a restriction inside your exhaust and make your motor WASTE energy trying to expell exhaust from your motor rather then having the exhaust create a low pressure zone behind it ( AKA lack of backpressure ) to scavange the next exhaust pulse out the cylinder through means of a pressure difference. you know high pressure zones like to go to low pressure zone. it's stuff like this that helps you breath :D. it also helps you get rid of the exhaust
 
doesnt the backpressure keep the torque at lower rpms?? i think tmx posted something on that issue once in a post i read and he was of a little more help than rx7 because he lacked sarcasm in his explanation. im not knocking u rx7 u make good points but not everyone knows everything about cars.. thats why we have forums.
 
Someone call? lol. Backpressure itself is bad, it does waste energy and it is not good. What you want is the next exhaust pulse to be at the dead low part, sometimes it requires slowing the pulse down some, but not making the engine push against it. Problem is, you can only optimize the pressure for one specific zone, so either you've got good low end, good midrange or good high end. For the V6, you want all the good stuff 3000-5500 since that is where you sit in a race more often than not, and it just so happens that somewhere around 2-2.25" duals gives the pressure waves the right speed for the scavanging effect in that range.
Course, if you don't have any pressure at all, the pulse just kind of sits there and evens itself out making the pressure waves loose amplitude, and you don't get the pulling effect.