Exhaust piping size - OEM system/Cat delete question

[racepar1]

Originally Posted by Kingtal0n

you dare mock the value of this diagnostic approach


we should all run around with really loud cars so that we cannot hear our engine's internals. That makes more sense.

That doesn't even make any sense. I have NEVER heard an exhaust loud enough to the point that you couldn't hear a knock or valvetrain noise. Maybe a top fuel dragster or something. As an inverse statement, I guess all racecars should have a quiet exhaust so they can hear the engine's "internals"...

[Kingtal0n]

Originally Posted by racepar1

That doesn't even make any sense. I have NEVER heard an exhaust loud enough to the point that you couldn't hear a knock or valvetrain noise. Maybe a top fuel dragster or something. As an inverse statement, I guess all racecars should have a quiet exhaust so they can hear the engine's "internals"...

I suppose you never heard a built engine quieted down to street noise levels... they make a racket. Especially with forged pistons slapping around.

Where did I originally hear of this? why I believe it was 1998, I was reading a book by David Vizard, something along the lines of how to build horsepower, Im sure. The book mentioned several times about how noisy the insides of engines could be, reinforcing that mechanical noise is an issue, for example,



There was a sentance that goes something like this, "anyone thats never heard a high performance engine quieted down to street noise levels..." and Ill never forget the impression it left on with me. What it says makes absolutely perfect sense, If you want to be able to diagnose the mechanical aspect of your engine, you can NOT be bothered to listen to the exhaust system. If you had the option of running the engine and listening to it through a loud exhaust tone, or simply turning it over with a tool (imagine you could spin the engine with the ignition off to several thousand RPM to listen to the mechanical parts without combustion getting in the way) I think you see what I am saying.

Besides all that, keep in mind my main excuse was recreation.
I can listen to my engine for the $28 it cost to purchase, and install my cutout to my arguably throw-away-able OEM exhaust system (no big loss if it falls apart, its OEM trash right?). thanks, that's all I really wanted. And it makes me sooo happy, puts a smile on my face for sure listening to the fire breathing dragon. Then I get a headache, close it off put the windows up and the A/C on and forget about it.

[omgosh]

If you have the hood up and you're outside the car it doesnt really matter what exhaust you have, you will be able to hear the engine.

However, when driving down the road windows up, it is waay easier to hear wacky engine noises, pumps dying, etc, with a stock exhaust.

[racepar1]

Originally Posted by Kingtal0n

LOTS of words, mostly bullshit...

I should have known you would respond with an epic novel full of crap. You can quote whatever book you want. I am a professional technician and have been working on REAL racecars or my entire life. Your diagnostic argument is bullshit. If you know the car and know what it should sound like you can pick out an odd noise pretty easily, even with an obnoxious exhaust. You want a cutout so you can be loud and obnoxious when you choose, quiet and low key when you choose as well. It's that simple, nothing more. I think cutouts suck and would prefer to have an exhaust that's moderate all the time. Not for ANY "diagnostic" purposes, just because I don't like obnoxiously loud exhausts.

[Bleakley]

To each, their own guys..

[Matej]

Originally Posted by Kingtal0n

you dare mock the value of this diagnostic approach


we should all run around with really loud cars so that we cannot hear our engine's internals. That makes more sense.

On the contrary, what I want is a decent flowing exhaust that is as quiet as possible.
My car will have a 2.5" OEM-looking exhaust with downturn tips, a mid-muffler, and a high-flow catalytic converter.
I know that some people love to play hot spec tuner with their car and flip a bunch of switches and adjust a bunch of knobs before every drive, but I just want something simple that will perform decently in any environment.

[ixfxi]

Originally Posted by racepar1

You want a cutout so you can be loud and obnoxious when you choose, quiet and low key when you choose as well. It's that simple, nothing more.

I understand where Talon is going, but I dont agree either. With his setup, you have a junk stock exhaust for "majority of driving" and then a cutout for... well, for nothing. You open it up, its obnoxious, and probably wont be used much other than a drag race here or there.

I'm more for a proper exhaust. Regardless of how its done, just a nice exhaust. Nicely bent tubing, the works. If you want adjustability, thats what silencers are for OR multi-valve exhaust. I just installed on in a buddy's porsche and its real nice.

I dont understand what all this talk about loudness if for, isnt that what turbos are for? best silencers, imo.

[Kingtal0n]

Originally Posted by racepar1

just because I don't like obnoxiously loud exhausts.

That is your personal preference. Mine is that I prefer not to hear anything while I commute in my daily driver, therefore, I require an OEM exhaust system, hands down no questions no other substitutions. I also require 350+rwhp making the cut-out absolutely essential. I have no other options... you might see this now?

Originally Posted by racepar1

If you know the car and know what it should sound like you can pick out an odd noise pretty easily,

Alright lets use this as an example.

Im coming to look at your car for sale. I've never seen it before, therefore, I do not know it. I have no clue what it "should sound like"

If the owner starts the car, and all I can hear is the noisy exhaust system, well I should like to ask him "sir, would you be so kind as to quiet the exhaust, so that I might listen to the engine for mysterious noises?"

now my device has a diagnostic value, in this example.

Again I want to point out, I added it for fun, thats it. And again, I can throw away my exhaust system and grab another one for... nearly free... at any time. If the reversibility, and affordability, are not fun inducing factors, well, I should like to know what other free/fun modifications I might make that are as strongly appreciated!

[Kingtal0n]

Originally Posted by ixfxi

I understand where Talon is going, but I dont agree either. With his setup, you have a junk stock exhaust for "majority of driving" and then a cutout for... well, for nothing. ]

So this is curious. The OEM exhaust system actually improves the performance of my car (it feels that way) for stock boost driving situations, over the cut-out, and comes OEM on the S14/S15 Silvia sr20det cars as well. I therefore feel that an OEM exhaust system is perfectly adequate and acceptable for power levels in the 250-280rwhp range on any engine, and not simply "junk".

People install an exhaust system for two big reasons.
1. noise
2. performance

In the case of performance, there is nothing like an open downpipe behind a reasonably sized turbocharger. This cut-out is useless to me now at stock boost levels, but when I install my gt2871r it will become priceless. I will not run an OEM exhaust system closed up behind an 2871r at 18psi of boost, no sir. It will desire something a bit more open to achieve 350~rwhp, I am sure of that. So in the first case, it is there in case I desire performance, provided I have the compressor to back it up.

In the case of noise, I would argue that an open downpipe is unreasonably loud, pointlessly loud in fact, this is true. With this in mind, I would also point out that I can operate the device partially closed, that is, with only a minor tone from the exhaust, at my discretion. It is not an OPEN/SHUT switch, but rather, a moving butterfly with an infinite selection of settings.

I have now shown that in both cases (noise and performance) the adjust ability of a proper cut-out system on an OEM exhaust can provide all of the benefits and noise scenarios that you might wish for. Indeed there have been plenty of times when a noisy vehicle next to me revs it's engine (or turns up its sound system) and I have been able to look over, and exceed that noise from below the drivers seat of my car with the flick of a switch, to the dismay of the other car's driver, only to pull away completely silent again, leaving them wondering wtf just happened.

Its all in good fun. Just happy to be alive and breathing, no need to get mad at the internetz

[ixfxi]

Talon... post a photo of your undercarriage. I would like to see a better visual of your undercarriage.

[racepar1]

Originally Posted by ixfxi

Talon... post a photo of your undercarriage. I would like to see a better visual of your undercarriage.

Whoa there, how did we get from talking about exhausts to taking pictures of each other's undercarraiges? I'm not sure I'm comfortable with the direction that this thread is going in...



Talon, there you go snipping tiny pieces of a post off and writing responses to them. Posts are meant to be taken of the context of the entire post, not just the tiny piece you don't like. If you're looking at a car and you are not capable of picking out noises that don't belong, then maybe you should bring a buddy that knows what he's doing. Are we listening for noises with our ears directly beyond the exhaust tip? I would pop the hood and listen from there. If I heard a noise that I didn't like I would bust out the stethoscope and pin point it. With our paper thin firewalls you can hear then engine louder than you can hear the exhaust in the cabin. Odd noises aren't hard to pick out. Most often that odd noise is accompanied by a vibration. If you're an actual good driver you can pick up that vibration through the steering wheel, floorpan, and seats. If you're REALLY good you can pick out the area of the car that the vibration is coming from based on where and when you feel the vibration the most. Your argument is invalid...

[ixfxi]

Originally Posted by racepar1

Whoa there, how did we get from talking about exhausts to taking pictures of each other's undercarraiges? I'm not sure I'm comfortable with the direction that this thread is going in...

haha

the problem is, we can go back and fourth trying to convince each other than one method is better than the other. in the end, i want to see what is attached to the bottom of this dudes car. in my head, i visualize a stock exhaust system with a cutout. nothing special about that. but maybe i am missing something.

i've never met a good mechanic who has trouble diagnosing a car that is too loud. either you know the sounds or you dont. aron, obviously you are a mechanic and know your shit. im just some gunslinging hobbyist/tuner but many of my mechanic friends ask me advice, so... in the end, we all rely on each other for help. but, there are plenty of less skilled individuals on forums. the miata forums is proof. most of the posts there are written by people who think the solution to every problem is changing plug wires and "seafoam treatment" - these people dont know their ass from their elbow. but hey, just because its a community doesnt mean its a community of professional mechanics. even mechanics dont fully understand all of the aspects of a car.

anyway. fuck the stock exhaust.

[Kingtal0n]

Originally Posted by racepar1

Whoa there, how did we get from talking about exhausts to taking pictures of each other's undercarraiges? I'm not sure I'm comfortable with the direction that this thread is going in...



Talon, there you go snipping tiny pieces of a post off and writing responses to them. Posts are meant to be taken of the context of the entire post, not just the tiny piece you don't like. If you're looking at a car and you are not capable of picking out noises that don't belong, then maybe you should bring a buddy that knows what he's doing. Are we listening for noises with our ears directly beyond the exhaust tip? I would pop the hood and listen from there. If I heard a noise that I didn't like I would bust out the stethoscope and pin point it. With our paper thin firewalls you can hear then engine louder than you can hear the exhaust in the cabin. Odd noises aren't hard to pick out. Most often that odd noise is accompanied by a vibration. If you're an actual good driver you can pick up that vibration through the steering wheel, floorpan, and seats. If you're REALLY good you can pick out the area of the car that the vibration is coming from based on where and when you feel the vibration the most. Your argument is invalid...

Ah, I see the reason for your confusion. I am here comparing all vehicles on the planet earth, including engines in cruise ships, or space ships, that is to say that the less the act of combustion interferes with your audible appraisal of any particular engine, the easier it will be to identify mechanical noise emitted. Since this applies to all forms of engines that utilize an explosive force to drive a surface, well it also applies to a 240sx. Just because you are able to overcome these difficulties (or assume that you are able to without measuring differences) does not make it any less true.

[Kingtal0n]

Originally Posted by ixfxi

haha

the problem is, we can go back and fourth trying to convince each other than one method is better than the other.

I do not think anybody claimed what was better. Only we have been mentioning our preferences.

I do not mind exhaust systems and changing the tone of the exhaust. In fact I would change my exhaust system every week for months using whatever was available to me, heres a picture I found of the corner where I would select a new exhaust each week that came from Japan while it was waiting for someone to buy it here in the USA.


My friend has a shop where things like this are possible, and so I have been able to try many different types of exhausts over the last 10 years, and have been spoiled. Perhaps that is why I have opted for this OEM/cutout method, since it delivers a full minimal-adjusted dosage of the raw noise this engine is capable of making, a racket to some but sweet music to my ears. Another reason I do not have a trendy exhaust system is because I am a poor college student, and just because I can barrow them does not mean I get to keep for free!

[racepar1]

Originally Posted by Kingtal0n

Ah, I see the reason for your confusion. I am here comparing all vehicles on the planet earth, including engines in cruise ships, or space ships, that is to say that the less the act of combustion interferes with your audible appraisal of any particular engine, the easier it will be to identify mechanical noise emitted. Since this applies to all forms of engines that utilize an explosive force to drive a surface, well it also applies to a 240sx. Just because you are able to overcome these difficulties (or assume that you are able to without measuring differences) does not make it any less true.

I am using a 240sx as an example because we all understand it. This example also relates directly to your claim as you own a 240sx. As Mike said, I have NEVER met a GOOD mechanic that cannot diagnose an engine noise due to a loud exhaust. The noises are coming from opposite ends of the car, it's really pretty simple to distinguish between them. And yes I do know that some cars have the engines in the back, however that engine is between you and the exhaust noise, also not difficult to distinguish the difference. I understand why you would want a quiet exhaust, I am just saying the diagnostic argument is invalid. I know, you read it in some random book so it must be true, just like everything that's posted on the internet...

[Matej]

Originally Posted by Kingtal0n

In fact I would change my exhaust system every week for months using whatever was available to me, heres a picture I found of the corner where I would select a new exhaust each week that came from Japan while it was waiting for someone to buy it here in the USA.

That sounds like a pretty rotten business practice.

[Kingtal0n]

Originally Posted by Matej

That sounds like a pretty rotten business practice.

Right, because used exhaust systems hanging on a shelf are worth more than a used exhaust system on someone's car. Or using a used exhaust system somehow uses it more when its in the USA. Trying to figure out your angle or reasoning behind this. In fact every car we got instantly acquired an off the shelf used exhaust system- might as well put them to work.

Maybe you'd like to clarify how using a used exhaust system here in the USA somehow makes it worth less for the next guy? Heck I just sold the very clean, very well cared for Apexi GT-Spec exhaust off my car to somebody who was very happy to listen to it on my car before he bought it off me. Would have been worth more on a shelf in the back of the shop? Don't think so!



It was a great system. In fact I feel like the car had more on the highway in 5th with this system than it does now. Although I've been through a clutch and a set of cams so my comparison might have been skewed a little.

[Kingtal0n]

Originally Posted by racepar1

I am using a 240sx as an example because we all understand it. This example also relates directly to your claim as you own a 240sx. As Mike said, I have NEVER met a GOOD mechanic that cannot diagnose an engine noise due to a loud exhaust. The noises are coming from opposite ends of the car, it's really pretty simple to distinguish between them. And yes I do know that some cars have the engines in the back, however that engine is between you and the exhaust noise, also not difficult to distinguish the difference. I understand why you would want a quiet exhaust, I am just saying the diagnostic argument is invalid. I know, you read it in some random book so it must be true, just like everything that's posted on the internet...

This isn't about being a good mechanic. This is about the fact that gasoline explosions make noise, and that noise can hide other noises. You might be unaware of them (because you can't hear them). I am sure you understand how this fact is the basis of my statement.

Yeah I can tell if my engine is sick just by listening to it run- that doesn't mean everybody can.

[Matej]

Originally Posted by Kingtal0n

Right, because used exhaust systems hanging on a shelf are worth more than a used exhaust system on someone's car. Or using a used exhaust system somehow uses it more when its in the USA. Trying to figure out your angle or reasoning behind this. In fact every car we got instantly acquired an off the shelf used exhaust system- might as well put them to work.

Not sure how other people feel, but I would not be happy if I found out that the shop owner lets his buddies play dress up with the parts before selling them to me. I realize they already come used from Japan, but after learning this, I would endlessly wonder which of the scrapes and scuffs and bolt marks were on it completely unnecessarily thanks to you, because I am quite OCD about such things.

It is one thing to buy a used item from a private seller who had it for his own personal use, but it is another when a business sells you a used part that someone else used even more in between the time it was listed for sale with pictures and the time I purchased it.

Maybe they are listed/photographed for sale only after you have had your joyride with them to fairly represent the current condition, and maybe they are just cheap throw-away exhausts that are not even posted online and are just there for people to come rummage through in person, but now how do I know you do not do the same thing with other parts as well, such as wheels, aero, turbos, and such?
Either way, you are not doing your friend any favors by bragging online that you get your pick at the parts from his shop before he sells them.

Originally Posted by Kingtal0n

Maybe you'd like to clarify how using a used exhaust system here in the USA somehow makes it worth less for the next guy? Heck I just sold the very clean, very well cared for Apexi GT-Spec exhaust off my car to somebody who was very happy to listen to it on my car before he bought it off me. Would have been worth more on a shelf in the back of the shop? Don't think so!

It is like buying a cool vintage coat online and the UPS guy comes wearing it to the door, because you know, it was already used anyway. Plus I probably wanted to see how it looks on someone else.

[Kingtal0n]

Nay, all cars that come to the shop for shop use/sale get an exhaust off the shelf. They dont sit there lookin' pretty, easier to sell them on a car, or with the car, etc... You must not own a shop that builds cars I guess.

I can appreciate your concern over used JDM parts but when you own 100+ copies of various exhaust system it really doesn't matter which car gets which system. At some point we just started taking them for granted, like lemmings. Same thing with wheels, tires gone? Whats on the shelf? Yeah give me those Ill wear them out.

[racepar1]

Kingtal0n is always right, no matter what...



Must have read that in a book too...

[mewantkouki]

A screenshot of kingtal0n's organic chemistry homework would make this thread complete.

[ixfxi]

Originally Posted by racepar1

Kingtal0n is always right, no matter what...



Must have read that in a book too...

hes so gaddamn smug

and i never understand his technical discussions

confusing, talon is

[S14kouki805]

Why the fuck did I just read this entire thread? I want my 30min back

[Kingtal0n]

This be da correction section for drinkin, smokin', and wastin' tiem



Now back to work