RedMax95

this is not for me, and it may sound stupid, but my friend is broke and wants to make the car louder without taking off the muffler, if i was to drill a small hole in the muffler would it make it any louder or would it have to be of decent size, it should reduce backpressure, and i think it is late enough on the exhaust path that it wont act like a leak, and i dont think it will lose all back pressure which is obviously a bad thing, so is this at all feasible? the hole wont be visible of course, btw this will only be a temporary setup, until he has time to save for some real exhaust

black019

you would instantly gain 5hp and 8tq. i say do it.

deezo

iTrader: (3)

It would fart.

emax02

iTrader: (1)

It would sound like a old car that needs a new muffler. BTW back pressure does not help a car at all. The velocity of a exhaust system is what counts, back pressure equaling performance is just a myth.

maxima_dumby

if it's loud you want, i say just take away your exhaust system
who needs a cat back anyways

RedMax95

ok, let me reiterize this is NOT my car, it isnt for me, i dont need you pw saying your stuff, actually it is good to keep some back pressure, totally eliminating it isnt good, all i need is a yes/no on whether it will be louder

maxima_dumby

in that case it wouldn't be louder
just sound nasty

emax02

iTrader: (1)

Back pressure does not do jack And NO

RedMax95

well ill tell ya what it really was on...i didnt want this moderated, and my normal forum is busy now, its for a 90 camaro v8 with dual exhaust, how do you think thatll change the sound? he is getting flows in a month

RedMax95

that contradicts everything ive ever read on here...

emax02

iTrader: (1)

From what I have learned the key to a good exhaust system is to get the exhaust to flow as quickly as possible. Very commonly people miss understand back pressure as a element to achieve better exhaust velocity, this is not true(to my knowledge). People usualy think that a exhaust system with to large of a diameter does not have enough "back pressure". In reality a exhaust system which is to large creates turbulance in the exhaust system and in return it slows down the velocity of the exhaust gases. It's not really the lack of back pressure. I don't know, it's hard to explaine and I'm tired

95emeraldgxe

i agree with redmax95........a small amount of backpressure is a good thing........you need to keep the exhaust flow fairly constant - with a large diameter exhaust it will start out slow but then speed up as you reach higher into the rpm band(low end power loss)

Dave B

Simply put, you don't want any backpressure. Better exhaust velocity equals power. Contrary to popular belief, larger pipes don't necessarily equal more power. Noise doesn't = power, either.

A hole in the muffler will sound like crap, regardless of the car it's on.


Dave

SLC I30t

iTrader: (1)

Hmmm, I was told that back pressure helps your car with building torque. Most domestic v8's don't benefit from this as we do because of their displacement. The assumption of better flow from your exhaust will create more power because of less back pressure. The Y pipe is a great example of better flow meaning more power. In any case, as long as you run a CARB or any other EPA approved CAT, it really doesn't make to much of difference what kind of CAT back you use because the restricted flow is at the CAT.

GuZo

iTrader: (6)

I was born in Portugal, and people over there do that to their motorcycles, it's ridiculous, I would never think someone would do it to a car, specially a MAX, leave that up to the civics...It will sound just nasty, my friend has a G20 and he had a legitimate hole in his muffler and it sounded horrible.

gtr_rider

iTrader: (50)

OK...

My brothers 240SX has the cat back broken and that thing is louder then ever! It doesnt sound bad, it sounds like he has intake and exhaust which he doesnt. I dont know about increase in power or anything cuz I havent spent that much time in it, but its loud.

RedMax95

ok, thats more like it, gtr do you know where in the catback it broken? also guzo check my other two posts, its not goin on a max

mzmtg

iTrader: (11)

It doesnt matter how many times and how many people have told you that you need backpressure.

It's still wrong.

SLC I30t

iTrader: (1)

Is that your opinion or is it fact.. if so please post your references.

Maximamike

Just cut the mufflers off and put on long chrome tips..

Dave B

No backpressure.....PERIOD..regardless of motor, 500cc, I4, I6, V8, V6, V10, turbo, etc. You want the exhaust system designed to flow with the highest velocity possible and you want to keep the exhaust gases as hot as possible. Adding larger than necessary pipes will allow the exhaust gases to cool therefore creating turbulence and ultimately restriction.


Dave

AznWontonboy

So thats why we have all those exhaust... instead of just out the header, and boom, no more exhaust pipes.

SLC I30t

iTrader: (1)

Ok I understand this for high end power. How does this effect the Torque? or does it not effect the torque?

y2kse

iTrader: (1)

All right, guys. Let's put this to rest.

http://www.magnaflow.com/05magazine/05sportc.htm

There is no such thing as "good" backpressure. Case closed.

RedMax95

well we went ahead and did it, decided against the muffler, so we made holes in the beginning of the 2 tips, it gave a little sound, fairly noticeable as the tips are long

y2kse

iTrader: (1)

Wonderful. So you got what you wanted and you learned something about backpressure in the process. Now you can join the ranks of those who've stopped making themselves look foolish by contending that backpressure is good for anything at all.

acMAX

I need some advice regarding this topic. I've got just an intake and
an HKS (rear section) exhaust. I'm going to buy an aftermarket Y-pipe and a custom b-pipe.

What size's would you recommend?

I'm thinking 2.5" Y-pipe with a 2.25" b-pipe but if I
can get better performance with different specs PLEASE
tell me.

Oh yeah...I'm planning on keeping my stock cat convertor....I should
punch that out too shouldn't I....

tifosiv122

iTrader: (2)

Im not sure where he lives, but if it gets cold, you'll see the hole from the "steam" that comes out....hint hint cops will not like that.

Erik

SLC I30t

iTrader: (1)

Thanks for the link. I wasn't trying to flame, there are just so many people that regurgitate bad information because their brothers step sister was going down on a guy who was talking to someones sisters cat on the phone who had a preminition, that if you mount your tires inside out they get better traction. So I just wanted to know if you've been on the phone or had facts to back it up. Sorry for sounding like an jerk.

gtr_rider

iTrader: (50)

Well, it is broken after the cat, we just took out the whole cat completely now, so it doesnt drag when the car is moving.

y2kse

iTrader: (1)

Check out the discussion in this thread, acMAX:

http://forums.maxima.org/showthread.php?threadid=112401

RedMax95

cold?!? in texas
its only gunna be this way for a couple months anyway

JoeGatineau

How else would you be able to fill it with water?

http://forums.maxima.org/showthread....ler+with+water