I was going to stop posting but I feel bad leaving you all hanging. Its up to you, want me to try and parry comments or disappear? I don't want you to feel like I am here trying to combat, I am not trying to start a fight. I just want novices to save their hard earned money, that is why I post in general- I am poor and I know how hard it is to make power while poor. The two often collide unfavorably, how can we have 500+ horses and still be poor? Been working on that my whole life.

For now I will try to help you see the way I see,
For me, there is no such thing as a manifold on an NA car. I do not see the NA engine floating in the air with a factory manifold. It always has a header. Manifolds are not an option, ever, for natural aspiration. Re-read my posts with this in mind maybe it will make more sense. Noise argument is against purposefully making more noise, not against incidental noise. You add 200 horsepower and generally noise will go up, it is incidental.


As the situation becomes more specific it must be specifically stated "what I would do" in each case. We need a goal first. If the car is to be 100% street and never goes to any race track, if the same car uses 93 octane, stock bottom end, no power adders, and needs to go 200,000 miles. This is one very specific situation I can address first. The first thing I would do is maintenance, and washing, for example. Engine mods are for clean engines. Once everything is up to date and clean, you define a power goal. Since we said no power adders and economy, daily driver, 93 octane, stock bottom end, 200k miles etc... your power goal is no longer a peak power goal but rather an area under the curve goal. In other words, the car will be leaving stoplights at 600rpm or 1200rpm, so a stock-ish or very mild camshaft is in order. A small diameter primary tube header, a tight converter, a reasonable rear gear, a well thought out PCV system, a high quality synthetic lightweight oil, paper air filter(very important), All the while still thinking of the engine without any exhaust on it. Think of it as an open header vehicle for a minute, even if it still has OEM exhaust on it (make plans around the idea of having no exhaust restriction issues in the future, allowing you keep the car silent for the time being). Any and all tuning should be done by the owner, so there is no need to pay for re-tuning everytime you change a part, allowing you to buy 1 piece at a time, thus tuning is not a "problem to overcome" or something to worry about when changing parts. If you stop right here and say " I can't tune my own car " then there is the real problem that should be addressed first, as understanding mechanical parts, engine operation, fuel injection, etc... is fundamental to owning this type of hands-on performance vehicle ( what was the point of wanting a fast car if you do not understand how it fully works? Instead, get a corolla, go to school get a couple degrees, get a real job, save real money and buy the fastest car you can dream of). There is no difference to me between changing my own oil and tuning my own engine. The minute you trust somebody else with your car, especially with parts installation and tuning, nevermind the oil changes, it completely obliterates the real value of "look what I built" aspect and now you have more bought, not built, with a wide open room for human error on behalf of other people that do not care about your car the way you do. So yes, keep the OEM exhaust and change the cam (remember, it is very mild), change your intake, heads, since the car is 99.99% economy daily driver nothing is going to be too wild and the OEM exhaust should allow you to keep driving the car. It won't hurt anything except output. Think of the oem exhaust at this point, as a sort of "bottleneck" or a "red ribbon" on the car. You know it hurts power, thus giving you something to look forward to. Once you are "tired" of driving your silent, mild engine economy vehicle, you now have this enormous dopamine opportunity available- cut the red ribbon- release the beast to its full final potential, and the car is complete.

If we step it up from economy daily driver to full out race car (I like to use extreme examples) then throw the OEM exhaust in the trash and leave it open header the entire time you upgrade the engine in the same manner for max power, with the exact opposite theme in mind as the previous paragraph, that is, instead of a "red ribbon" effect, you get to complete the car fully and then add a noise reducing, power reducing part (it re-cages the beast) so that you can actually meet some kind of noise restriction (some tracks do, or some ears do). In this way, the parts are far more radical, and the engine no longer needs to have any torque at 1200rpm, or 2000rpm, or even 3000+rpm. You can go ***** out and not care about economy or noise so much. It is not the novice pathway, not a daily driver pathway, and so it is not what I am addressing in the previous postings. I am thinking more along the lines of novices with fresh cars, looking for initial mods. Ask some 30-40 year olds and the theme is more "I want my car to work properly, not stink at stoplights, to be enjoyable and have A/C and not make a bunch of noise". This is where I am coming from most of the time.

You are racing... against yourself or a friend. It isn't for money. Money changes everything. Cars I race for money will have multiple race winning systems in place to ensure success, such as hidden progressive nitrous controllers, traction insurance computers and hidden fuel cells filled with leaded C16. If we rule out money as a factor in winning the race, then the race becomes much less important. You can keep the engine much safer, which costs power, and it becomes an excuse ("well, I could make more power but its too dangerous so my car is slower"). So now max effort, max power is off the table, and I find myself asking "Is a 400 horsepower 3800lb vehicle actually fast? Is it worth driving? how much does it cost to build that?" Start adding up the cost of all those parts, heads, cam, intake, whatever. Include exhaust or not it doesn't matter. We can also cross compare vehicles, say there are 2800lb vehicles you wouldn't mind owning or driving, where an LS engine also fits easily. Shaving 1000lbs could make your 400 safe horses feel like 450+ instead. The 'racing but not really racing game' isn't just about understanding and maintaining your own ride- its about finding a pathway that you can actually drop hard earned dollars into and be happy with for as long as you own the car, and if the day comes to finally sell it, it would be nice to get back more than you have invested. To do this isn't a necessary for many, so those individuals may laugh at my theory or procedures and say "wtf", but I assure you they are with the best intentions of getting the most (safety, longevity, learning experience, love and pride) out of whatever ride you own. At this rate, it isn't about the power at all, it is about the huge grin on your face you get when you drive. No matter what anyone says on any forum.

 

Don't leave, this can actually help you see the way LSx guys see on here and maybe help you help them in return, as a lot of your views are highly skewed from being in the imort crowd, using FI and doing swap. Your terminology needs work is the biggest confusion on here - exhaust = headers too. If you say leave the exhaust stock that means headers too. You should be saying muffler or catback if that is what you are referring to.

And here is what Im talking about. From the factory 99% of cars come with exahust manifolds. LSx cars come with exhaust manifolds, never headers. So when you say you leave the exhaust along that does include the manifolds. And if you want to add LT headers this also includes changing out the Y-pipe and cats on Fbodies as they will not fit with LT headers. So assuming for the sake of simplicity that we want to stick with another Y-ypipe this only leave the stock catback/axle back exhaust on the car - and if that is what you want to leave stock then you say just that, that is not "stock exhaust" that is "stock catback".
And now for the noise argument, this seems to another import vs LS thing. On an NA build anything that adds noise for these engines will generally add power as well, even its only a few hp its still a gain. So you can completely forget the argument all together.

had to condense things down due to character limit. But so far I agree with this - you do replace the exhaust, you replaced the headers.

Quiet the rant. We will have to agree to disagree here as its completely unrealistic to think every single performance car owner is going to buy tuning software and learn to tune their car. While I agree they probably should, and it would certainly be a good thing if they did (and actually learned to tune, not just adjust things and blow their car up). Its much much easier and cheaper (for us poor guys) to go to a reputable tuner with a dyno and get a real dyno tune and know where you stand. For the record i own hptuners as well but if you think that by letting someone professional tune your car on a dyno negates everything else you've down yourself then god help you.

Terminology error again, keep the oem catback. The exhaust is no longer oem when the manifolds have been changed.

So again with these cars you don't have to do that. You could have changed the catback from the get go as majority of aftermarket catbacks will support just about any kind of average power goal you throw at them. If you are looking to make a 1000rwhp car then that is a different story but I hope you know that already.

I think you are in the wrong crowd then, most Fbody owners are typically under 35 Id say, and all V8 fbody owners are in some way a "hotrodder" in the sense they did not buy the car to sit at stoplights with the AC on and not hear any exhaust rumble. If that is not the case then they simple bought the wrong car as they could have gotten something much more comfortable and quiet for the same price or less, but drastically sacrifice performance.
Also replacing the catback adds no additional smells either... Adding LT headers with no cats on the other hand - you're kinda contradicting yourself here.

Another strange rant/story.
I like that you are implying fbodies are 3800lbs, I assume this is the average no-weight reduction fbody with a 200lbs driver. Did you know some of these v8 fbodies depending on trim and option weigh in around 3300lbs totally stock? - Might want to recognize that.
As far as finding a 2800lbs car (is that 2600lbs with a 200lbs driver too?) that you want to go through the trouble of swapping an engine/trans into that is great but that is again unrealistic to think everyone wants to or is capable of doing so (not just mechanical and wiring knowledge, but having the time, space and tools to do the job as well). Id love to get a clean, blue FD and do an LSx swap, however realistically I do not have the space or tools to do it, and likely do not have the time to invest either.
You could just buy a C5 Z06 and do some weight reduction, as Ive seen those dip below 3000lbs without driver.

 

Your most recent post makes a bit more sense, but why do you keep saying exhaust and then manifold/header separately? Headers are a primary part of the exhaust.


It's like saying, keep your tires stock, but change the drive tires. What? So then the tires aren't stock! Because you changed the drive tires!

 

I'm at the upper age limit of this group, so I'll give an opinion. Most folks want their cars to work properly (whether it does or not is a different matter though), so I don't think that's age specific. My '71 is reasonably loud, it generally smells like a chainsaw when running, and it was not built with A/C. This didn't bother me when I was ~20 and it doesn't bother me at ~40. I wouldn't necessarily want something like this as true daily driver, but that has little to do with the noise or smell (I have no issues with either, and I actually like the noise.) The complications of driving an antique car in Great Lakes region weather, plus all the worries of leaving it places any time I need to go inside a store, etc., make it poor daily driver material. If not for that, I'd be fine driving something like this nearly all the time (though A/C is nice for those two months per year where it gets above 90° here.)

Having said that, many of us at this age have designated daily drivers, cars that are separate from our hobby related vehicles. At that point, some extra noise from a weekend toy is often welcome. My usual group at the local cruise nights are all guys in the ~40-60 age range, and none of us have stock mufflers or complete stock exhaust systems on anything other than 100% assembly line original concourse level show vehicles. It just so happens that in addition to the "cosmetic" (as you've put it) enhancement of improved sound, there is also a performance and/or MPG benefit in every V8 application that comes to mind.

During periods when I've had V8 *true* daily drivers, I've never left the exhaust stock on these either. Granted, I wouldn't want them quite as loud as my Nova but, again, I don't find silence to be desirable when it comes to a V8. So, going as fast as possible while also being as quiet as possible has never been a goal of mine. The audio characteristics of a stock muffler are only desirable to me on a 4 or 6 cylinder vehicle, plain and simple.

 

Ah I see my big mistake. While trying to keep initial post size down I left out critical info. Good call on 'catback' terminology, Let me re-write my initial post then.



I realize the cars come with exh manifolds, but I never think of them as having manifolds since nobody in their right mind would keep them on the car, its one of those obviously needs to change things about an engine you are taking seriously if leaving it NA. Some things that you get with a car have no place being there, like some factory brakes and open differentials. We wouldn't ever make a plan around an open diff, or consider it as "there on the car", in the back of our minds, its already gone before we even get the car.


I looooooove listening to an engine. Doesn't matter if its a 2.0 or 6.0, I absolutely adore the noise they all make (edit: turbo anything- not naturally aspirated small displacement, which IMO sounds terrible). I will always use a cutout if possible. I can't go more than a day without listening in. Back before I could get cheap ebay cutouts I would unbolt my cat-back and use a coat hanger to tie it up out of the way just so I could listen to the engine open downpipe. For the record I've never owned a naturally aspirated 4-cylinder, all of them have been fire breathing dragons. I only caution novices against "early noise" in cars, better to focus on other aspects first and come back later to the noise part. Its nice to be able to turn "off" the noise when you want.

It really isn't a big deal. Only worth 2 sentences and 2 minutes of time, and added a warning about cut-outs being finicky (the cheap ebay ones are if you don't take care of them).

Thanks for talking to me like a human by the way, I do have feelings

 

Displacement isn't a factor in this for me, but cylinder count sure is. I don't especially like significantly increased exhaust volume on anything other than a V8, I8, or V16 (not that you will encounter many of these without a time machine.) Others should remain fairly quiet/close to stock IMO.