Aftermarket Muffler on the GS = power loss or gain?

[seneca]

Hey all.

Like the post says on average have you found that adding an aftermarket exaust on your ride has given or taken from your overall power? Focusing on the GS but all you 4 bangers are welcome to post!

I've head many different stories of how our cars shouldn't have aftermarket mufflers cause they lose power...and yet I've also heard the complete opposite!

Personally I'm not changing mine for power...I just can't stand the look of an old brown exaust peeking out of my new body kit! I need a nice silver slant cut back there to finsh the look of the back!

So let's hear it:

[papa roached]

you wont notive a difference on the K8

[RoundTop]

I respectfully disagree. Many people do aftermarket mufflers wrong.

There are some good posts about volume vs. velocity on the board.

My stock muffler finally fell off so I got an aftermarket one. There was a large difference. Mainly the shifts were easier due to less backpressure.

I didn't change my exhaust tubing from stock, and my muffler has a silencer in it, which keeps just enough backpressure to be good. I've taken the silencer out before (for mine it is all of 2 bolts) and my low-end power went down (and exhaust got louder) as my backpressure and velocity went down.

So yes, I would call it an appreciable difference. You want a PERFORMANCE muffler, not a fart cannon or loud machine. Maybe not fully in power, but in shifts it makes a diff.

[papa roached]

i have never had a problem with my shifts due to back pressue and i dont see how the exhaust flow can effect the tranny and your shift linkage i put a perfomrance muff on my last GS and saw no gains at all in shifting (as you said) or perfomrance and when i put the silencer in the performance was worse than stock

[Josh]

most of the time just a mufler isnt enough to feel. but its there. backpressure helps you in the low end, where if you were to have a straight pipe with no muffler you would probably feel a loss in low end but would probably be nicer in the high. when i changed to my tusudo muffler on the stock engine and exaust pipe, there was definatly a differance. most people think its faster cause its louder. i really wanted to go with the Mazda Speed but not enough cash. that would probably be the best choice for an exaust.

[m92_MX3]

so what if someone was to run 2.25 pipe from cat back to a performance muffler ? and i am just conserned about bottom end for the strip

[Josh]

the thery is 1" per L of displacement. so 2.5" on a 2.5 would be perfect. there are a coulple of people on the board who know a heck of alot more than i. but there are ways to change the velocity by reducing the pipe in a section to create a supercharger like effect, where the exaust swerling actually helps pull the exaust out faster.

but i would go with 2.5". i just think most people go too big. like 3" on a 1.6L 4cyl is just a bit too big. not really a need to go that big. even with a turbo, unless there running some kind of drag turbo then i could see it.

[DJ]

I went through the same thing about a month ago. My rusted muffler finally rusted apart. So I thought that was a good excuse to get an aftermarket one. But after calling around and researching the only non-fart pipe one that actually added decent HP was the mazdaspeed one which costs ALOT and not sold anymore unless you find it in a warehouse somewhere (expect even higher price now due to being rare). So I just said screw it and got another stock one (well Midas equivalent because no mazda dealer is in town and I needed a car ASAP that didn't make me deaf). Btw, don't go to midas!

Also, I didn't realize how LOUD the car is when the pipe rusts off before the muffler. Damn, I was pulling off the highway and I thought my back window was going to blow out.

It looks SO much better and sounds about the same.

If you want to know: direct from Mazda a 1 year warrenty muffler costs $140 Canadian. And a Lifetime warrenty one costs $297 Canadian.

<small>[ September 01, 2004, 07:53 AM: Message edited by: DJ ]</small>

[seneca]

See, now you guys aren't helping much (actually you are ) I wanted to hear yes, it's either the same or better! lol But I guess this isn't a perfect world after all...lmao. Well like I said, I cannot stand the look of a stock exaust on my car so I'll still be doing the change. Hopefully I don't lose any power. I mean, on a K8 with only an intake I don't think any power loss can be had. At a whopping 130hp I can't afford any power loss...lol.

Well I guess the best thing to do is try it. If it doesn't work? Meh.

tyson

[DJ]

The way I see it, if a $1000 cat-back mazdaspeed exhaust only adds 11HP, then what is a cheap universal muffler going to add other than the worste sound ever and bring the RICE factor up? The universal ones may take a way a little HP due to a bad design and back pressure or you may gain a couple. Either way you won't really notice the gain or loss but you and everyone else will notice the farting sound coming from the car.
So I would suggest just getting oem replacement or your local muffler's place equivilant with a lifetime warrenty and get some nice chrome tips so it looks all nice and shiny and has the same amazing sound to it.

Btw, if you check out my cardomain pics you can see how much the look of the car changes when you no longer have two tiny little rusted pipes coming out of the back.

<small>[ September 01, 2004, 09:51 AM: Message edited by: DJ ]</small>

[ZEmadman]

same thing happened to me at the beggining of the summer the exhaust pipe rusted away and BROKE off just before the muffler. driving home from work one night, and all of the sudden the car sounds like it's going to explode....it was so loud that all the Fast&Furious Civic rice boys were creaming themselves as i'd drive by. i was so embarrased. the vibration was so loud it would echo in your head...it was terrible.


i got a OEM style one except this one's only got one 2" outlet. i cant say i really noticed a HP change, but then again when youre only adding 5-7 HP w/a catback exhaust would you even notice the difference. i cant imagine a muffler giving you more then 3HP.

if you want a good muffler, get a flowmaster, it's a quality part, and it's not too expensive (depending on what model you get).

<small>[ September 01, 2004, 01:31 PM: Message edited by: ZEmadman ]</small>

[Josh]

yah thats kinda the way it was for me in the RS with the ATX just before i put the turbo and the MTX swap. i had 2 1/4" all the way back no cat no resionator and just the coffie can. loud as hell! you would go numb sitting in the car driving down the road and you didnt even want to roll up the windows. you would get our of the car and still couldent hear. on the freeway i was vibrating the indside of peoples cars 3 lanes over. it was just nuts. then i put the turbo on and it quieted down by more than id say 2/3rds. i still need to put a cat in and im debating a resonator. we will see im goin gto put a dump valve in for the track.

[seneca]

Well...it's on!!! Omg...it sounds sooo much better. And guys...it's not all that loud and ricey. In lower rpm's it has a louder and lower growl (much unlike the civic boys) and turns into a very very low humm at higher speeds. I mean it's nothing like what I was expecting! You can definantly notice the change at lower speeds and rpm's but other than that it just sounds like a more powerful stock exaust. It pretty much sounds like it has balls now I'm in love.

But I didn't do it for sound, or for power. It's purely asthetics! I'll be sure to get some pics up after I install my new Sparco Gas cap cover too

Tyson

<small>[ September 02, 2004, 06:06 PM: Message edited by: seneca ]</small>