But as the article said, you may loose power on the low end, but you'll gain more on the high end. Back pressure allows the car to run better at lower RPMs.
'

 

Additional Info:
https://my350z.com/forum/7435408-post15.html
https://my350z.com/forum/7435586-post16.html

 

The 3 of you obviously have no idea what you are talking about because my car now sounds amazing and uniquely import sounding, as have attested everyone who has done a muffler delete. Everyone I have shown my exhaust to have been COMPLETELY BLOWN AWAY. Think before you make idiotic and ignorant statements. If you're jelous, well, can't help you there hahah.

To everyone else. The only reason I am posting right now is to inform others that I have indeed gain power and torque, my tires now squeal in second off the line which they previously did not. Other sites have claimed 10rwhp from the mod. At the begging the car will be slower....but after the ecu adjusts you will tell the difference.

I really don't understand how some of you can't comprehend how the muffler is nothing but completely restrictive. All it does is take your exhaust flow and completely **** it up by doing the exact opposite of what it's supposed to and bouncing the pulses onto one another.

I'll use the garden hose analogy just the same. If you improve the flow of the garden hose up to the head, it will hardly matter since the head will restrict it just the same as before. No matter what flow you have before your exhaust, it will still be greatly reduced by the muffler. Having mufflers on aftermarket exhausts is senseless except to reduce the noise. So I have similar gains to people that spend 600-1500 dollars and much better sound (because of their muffler!). If the aftermarket exhausts had no mufflers they would make likely double the gains.

If you are contemplating doing this mod....DO IT!!! It's a win in every category and I could not be happier!! Power/torque, engine efficieny, and amazing sound. The only downside is if you cruise at 90-95 mph like I do on the highway, you'll have to sound deaden your interior a bit! Oh and I only spend 190 bucks for a superb job.

Anyways I don't really want to waste my time arguing it's basic physics so you guys can choose to believe what you will. Doesn't change how much love I have for my Z and how awesome she is becoming

Here's a video of her (way louder in person, and videos never do them justice sigh)(also this is right after the install, so she was slower till the ecu adjusted):
<iframe width="560" height="315" src="http://www.youtube.com/embed/R7VggS9PlmY" frameborder="0" allowfullscreen></iframe>

 

^ I have seen you around driving in Orlando. Car does indeed sound nice.

Now, on the topic of the muffler.

1: you are not an engineer.
2: I have not seen a single site boasting said 10 hp dyno sheet
3: People on this site are giving you a hard time because of your "honda mod" to the otherwise "godlike" financially burdening vehicle that is the 350z in some peoples eyes, take it with a grain of salt.

I have welded these setups before for other Zs and 240sx's. THE only thing this does is make the car loud. "I" am not an engineer, but to my knowledge a muffler "muffles" the exhaust tone. Your (and mine) N.a car will only "sound" fast with this mod. In my book it doesnt mean the mod is useless or ricy. I oped out of this mod, and I went out and got a used SRS exhaust, midpipe and Y pipe for 100 bucks in Tampa. The car sounds nice and looks nice, and it also doesnt give the impression that "im trying to sound like a race car driver". I have read many articles about mufflers and all point to the same thing:

" Mufflers are in place to control exhaust tone and regulate pressure of the exhaust, removing them with a more free flowing exhaust (AKA straightpipe) does absolutist jack squat"

In the end its your car, and you can do with it as you please. Dont argue ( and this goes to everyone else as well) on the internet, if OP wants to make a PVC exhaust then he will do so regardless what anyone else says...in the case that the latter is done, one can only hope the car winds up stolen and sold for parts at a honda forum. (no offense OP)

 

Thanks it does sound great.

However just because you haven't researched and therefore seen the evidence does not mean it doesn't exist.

Second, I'm an engineering student, was top of my physics I class and am top of my physics II class. I applied my knowledge to what others have claimed and evidence on the internet to come up with my belief. It is way more thought out than what some of the people on here think.

Regardless, you wishing my car to be stolen and scrapped, what the **** is wrong with you?

Right when someones Z got broken into and keyed on the forum.

EDIT: I see that you personally aren't wishing that upon me sorry...but still man. If you have any love for the car you wouldn't want to inflict that onto another Z owner...

 

This is not exactly correct. Backpressure is a necessary evil. It is a consequence of good scavenging. High exhaust velocity is required for good scavenging. High exhaust velocity requires small pipes. This creates backpressure. Backpressure means that the engine has to expend some of the energy that could have been used to make the car go fast to instead push the exhaust out the back. The best possible exhaust design would be an exhaust with good scavenging and no backpressure BUT this is not possible so a balance must be struck between good scavenging and low back pressure.

Low end torque loss being caused by backpressure decrease is a myth from the carburetor days. Old carburetor cars were not able to adjust the mixture when the flow rate increased due to the decrease in back pressure. This would cause a lean mixture, loss of torque, and in some cases burnt exhaust valves. Re-jetting the carb(s) was required to correct this. Today's modern cars are generally able to compensate for this and maintain the correct mixture. Loss of power and/or torque on a modern car when back pressure is decreased is likely due to decreased cylinder scavenging (i.e. low exhaust velocity, pipes are too big).

 

Requoting myself since its obvious you did not read them. Also, lawl at phyics "accolades", wait for the higher level engineering courses.

 

I'm no expert. Read a little & used common sense. I agree with you & well written. My thinking is less restriction = better. Back pressure is a myth. Velocity + no restriction = "The BEST". That's why I never got after market exhausts. No cats, original mid pipe, resonator delete. Works for me/just my opinion. Velocity is very important in N/A cars. Boosted very powerfull engines, just get the exhaust out(dragsters/funny cars/twin turbos).Smaller pipes create high velocity/speed. A balance is best....just my thoughts.

 

I think the OP is correct just so long as pipe diameter is close to stock. Also wasnt this myth busted in earlier threads? I was attacked one time on this site for mentioning electric
exhaust cutouts. If you do a muffler delete could you tune your exhaust with velocity stacks for sound or the... backpressure?

 

i have a muffler delete and my car sounds like an F1 and actually moves lol, had it for months now n never got pulled over, it all just depends on how u drive the car. Reppin Z's real nice too, search up my youtube channel UWKCAL and check out one of my vids of the z, you'll prob like it actually.

 

 

Worth re-quoting these as Tony @ Motordyne already covered this in much more specific detail back in 2009.

https://my350z.com/forum/7435408-post15.html

For reference, that's the specific post start point.



PS, straight through rear muffler is a really crappy sound, sounds good at first, then really borks on your ears TDX2 FTW!

 

This is what a cutout is for, while on the dyno open a exhaust cutout and see how much hp you gain. If the gain is minimal then your exhaust setup is pretty good, if the gain is large then your exhaust system is holding power back.

While on the dyno with my car i opened the cutout and gained 4 whp and 3tq . This is with a 3" exhaust system


On a similar car ive seen a stock exhaust system with a cutout, open that on the dyno and it was over 20hp!


Sure the few hp i gained from a open exhaust was nice, but not worth the sound, only time it would be worth it is at the track.

 

Motordyne has made me really satisfied freaking car sounded loud and awesome.

 

Check out this video on YouTube:<br/><br/>http://youtu.be/5oXG0TKlQ4I

Sorry for the crappy iPhone filming by the Wifey.

 

I like the crush bends.

 

On the stock system? yeah, some of them, especially the y-pipe, are terrible

 

No, in the video with the blue Z and no muffler.

 

Oh, i beg your pardon, wow, yeah good point!

 

Many aftermarket systems are open exhaust but they create a better
harmony in the sound. For a muffler delete has anyone tried velocity
stacks for tuning sound?