Stock exhaust system

[Mach1 Driver 560]

My old girl has a single exhaust since its a 2v 351w. This link shows what looks to be the stock setup for a 4v 351w: http://www.drakeautomotivegroup.com/Store/Product/C9ZZ-5257-CRE.aspx?wid=141

I'm just curious what the two small "glass-pak like" devices are before you get to the vertically mounted transverse muffler. This has 2-1/4 " pipes, and i wouldn't want to go less than 2-1/2.  I want a quiet system, but cutouts to make it loud on the rare occasions when I want it.

[barnett468 418]

they are resonators to reduce potential "drone".

why do you want 2 1/2"?

there are no 2 1/2" stock type systems that i know of.

[Mach1 Driver 560]

What I want is quiet, and stock is quiet. I don't necessarily want 2-1/2 but I want it to breathe well and be quiet. Perhaps both are not obtainable. 3" is tough to fit by most accounts, and 2-3/4 is scarce I believe. 

Do you think 2-1/4 duals are adequate for 400-450 hp?

[1969_Mach1 333]

I think you should have a 2-1/2" diameter exhaust system for the horsepower goal you have in mind.  As far as quite, muffler and exhaust tip choice is the key, and use full length tail pipes.  Myself, I don't like the sound you get from Magna Flow mufflers.  But that;s simply my preference.  Whatever muffler you choose, select the largest possible that fits well under the car.  Also, exhaust tip diameter has a large affect on exhaust noise.  Keep the exhaust tips close to the diameter of the pipe.  Larger diameter exhaust tips increase the exhaust noise.

I use Borla mufflers.  Relatively quite under normal driving and loud when driving aggressively.  But, the Borla mufflers do not create the low pitch in car drone you get from chambered mufflers like Flowmaster.  Borla's are a straight through design similar to Magna Flow but have a different sound.

I think an old school Turbo type mufflers, tailpipes, and not large exhaust tips would give you the quitest sound for an aftermarket system.  Lastly, an X-pipe instead of an H-pipe mellows the exhaust note a little and is suppose be better for performance.

[barnett468 418]

6 hours ago, Mach1 Driver said:

Do you think 2-1/4 duals are adequate for 400-450 hp?

marginally but i would use straight thru mufflers and a cross over.

[barnett468 418]

4 hours ago, 1969_Mach1 said:

As far as quite, muffler and exhaust tip choice is the key, and use full length tail pipes. .

quiet mufflers will kill a lot of hp so there is no point in using 2 1/2 just to choke it off with quiet mufflers.

 

[barnett468 418]

4 hours ago, 1969_Mach1 said:

I think an old school Turbo type mufflers,  would give you the quitest sound for an aftermarket system. 

not even close. those things will be loud with over 400 hp.

[barnett468 418]

4 hours ago, 1969_Mach1 said:

...not large exhaust tips would give you the quitest sound for an aftermarket system. 

there is no point in running pipes that have more area than the area of the tips.

heres one of many free area calculators on the net that you can use.

http://www.calculator.net/area-calculator.html

 

[Mach1 Driver 560]

53 minutes ago, barnett468 said:

marginally but i would use straight thru mufflers and a cross over.

Thanks for the recommendation Mike, but while you took issue with much of 1969_Mach1s post, you weren't very specific; you recommended a straight through muffler and a cross over. Obviously the cross over isn't the issue.

I know this is an odd request, but could you recommend a quiet straight through muffler, or is that an oxymoron? Is there a company that I should start with? I believe it must be possible (but no one asks for it) because there are many years of modern stock Corvettes that are smooth and quiet and have as much or more HP. I can think of about 150 examples in my Vette club.The only quiet exhaust on a classic Mustang in my Mustang club is a stock exhaust, and I wouldn't consider them performance systems.

[barnett468 418]

4 minutes ago, Mach1 Driver said:

Thanks for the recommendation Mike, but while you took issue with much of 1969_Mach1s post, you weren't very specific; you recommended a straight through muffler and a cross over. Obviously the cross over isn't the issue.

a crossover isn't as important if the exhaust system is going to be choked off significantly anyway with quiet mufflers and tiny exhaust tips etc.

one of the quietest systems is the stock system.

[1969_Mach1 333]

Yeah, there are a lot of topics I don't agree with barnett468 on.  It's just the way it goes.  Different opinions and thoughts. 

 

[1969_Mach1 333]

Mach1 Driver, you mentioned something to do with Corvette mufflers.  A good friend of mine just had the stock mufflers replaced on his Challenger SRT.  I have to ask again what brand they were.  But they were from a company that makes a lot of the mufflers used on late model Corvettes.  They were relatively quite under normal driving.  A little loud with real aggressive driving.

[barnett468 418]

1 hour ago, Mach1 Driver said:

Thanks for the recommendation Mike, but while you took issue with much of 1969_Mach1s post,

I didn't "take issue" with his post because I didn't even read it until just now. 

 

[JayEstes 172]

I have a stock 302 system and I put 2.25 dual exhaust on from this company: 

https://www.precisionexhaust.com/

I really liked working with them, they can custom make some of it, but as I recall, alot of the puzzle is to figure out what are you doing with headers/manifolds.

I would say that my exhaust is a quiet system.  Disappointingly quiet sometimes - sounds nice from behind the car, but just not a lot of rumble otherwise.  I just bought a stock exhaust system with mufflers that they recommended.  It has an H-pipe too.

It's very hard to pick the muffler that sounds right to you, buying a mail order exhaust like this, unless you know what a particular muffler / pipe /engine combo sounds like ahead of time.  I took a chance, and mine came out quieter than I wanted, but it's a nice system, and the thing bolted right up (bends were perfect for my car) absolutely no problem.  I believe the guys at precision exhaust really know what they are doing.  My cost was about the same as the system you linked, shipped to TX from CT.

Jay

[Mach1 Driver 560]

15 hours ago, barnett468 said:

I didn't "take issue" with his post because I didn't even read it until just now. 

 

Really? If you go back and look at his first post (the one I'm talking about), you took issue it and quoted him in the next 4 consecutive posts- so I know you read them. Jeez no reason to get combative with me too. There is no doubt that you just flat-out know what you're talking about. I find you the best resource on any of the three forums I frequent. Throttle back a bit dude! ;) 

[Mach1 Driver 560]

16 hours ago, 1969_Mach1 said:

Mach1 Driver, you mentioned something to do with Corvette mufflers.  A good friend of mine just had the stock mufflers replaced on his Challenger SRT.  I have to ask again what brand they were.  But they were from a company that makes a lot of the mufflers used on late model Corvettes.  They were relatively quite under normal driving.  A little loud with real aggressive driving.

Thanks, that sounds good, I'm interested.

[barnett468 418]

1 minute ago, Mach1 Driver said:

Really? If you go back and look at his first post (the one I'm talking about), you took issue it and quoted him in the next 4 consecutive posts- so I know you read them. Jeez no reason to get im notcombative with me too. There is no doubt that you just flat-out know what you're talking about. I find you the best resource on any of the three forums I frequent. Throttle back a bit dude! ;) 

ummm...i'm not getting combative with anyone so don't make assumptions. i will look at the posts you are referring to but i probably thought they were from you because your names are similar which is why i mistakenly stated that i didn't read his. irregardless, whatever i stated is accurate. it's really that simple.

 

[Mach1 Driver 560]

17 hours ago, barnett468 said:

a crossover isn't as important if the exhaust system is going to be choked off significantly anyway with quiet mufflers and tiny exhaust tips etc.

one of the quietest systems is the stock system.

That makes sense but the stock dual system does have the crossover

[barnett468 418]

1 minute ago, Mach1 Driver said:

That makes sense but the stock dual system does have the crossover

yes, i know but that is not with a 400 - 450 hp engine.

[Mach1 Driver 560]

1 minute ago, barnett468 said:

ummm...i'm not getting combative with anyone so don't make assumptions. i will look at the posts you are referring to but i probably thought they were from you because your names are similar which is why i mistakenly stated that i didn't read his. irregardless, whatever i stated is accurate. it's really that simple.

 

I don't doubt that Mike. Hell, if its an item of interest I often copy your posts so my aging brain doesn't have to remember the details. 

[barnett468 418]

do you want your system to be as quiet, or nearly as quiet as a stock system?

 

 

[barnett468 418]

Just now, Mach1 Driver said:

I don't doubt that Mike. Hell, if its an item of interest I often copy your posts so my aging brain doesn't have to remember the details. 

yeah, we have no probs even if we sometimes joust a little and i see that one of my replies in which i copied one of your quotes had nothing to do with what i quoted from you but i forgot to delete your quote from my post, lol.

 

[Mach1 Driver 560]

6 minutes ago, barnett468 said:

do you want your system to be as quiet, or nearly as quiet as a stock system?

 

 

That's the goal, yes. It still has the original system and has a little rumble.

[barnett468 418]

well, this is a little complicated because nearly no matter what you do, it will be louder to some degree with a dual exhaust system, however, it will have more power with a stock dual exhaust system then it will with the stock single exhaust system.

if you can accept the amount of power it has now, then you can definitely choke down a dual exhaust system a little but then there is little point in running a dual system unless it is simply for cosmetic reasons.

walker, makes a lot of old style stock type glass filled mufflers and these are some of the quietest ones available.

the more volume the muffler has, the quieter it will be if all else remains the same. one of the quietest systems would be dual stock type mufflers under the car into a stock type transverse muffler behind the rear axle. with a system like that, you could run slightly bigger pipes to reduce the restriction caused by the mufflers and it would still be reasonably quiet in the cab because most of the sound will be going out the tail pipe.

also, installing dynamat on the entire floor area will help reduce noise and the more of the car you put it on including the rear wheel wells, doors, and roof etc, the quieter it will be.

also, choking an engine with a restrictive exhaust cause them to put more load on the cooling system but if it doesn't run hot now, you are ok in that area.

 

 

 

 

 

 

 

[Mach1 Driver 560]

19 minutes ago, barnett468 said:

one of the quietest systems would be dual mufflers under the car into a transverse muffler behind the rear axle. with a system like that, you could run slightly bigger pipes to reduce the restriction caused by the mufflers and it would still be reasonably quiet in the cab because most of the sound will be going out the tail pipe.

That's what I was hoping for and why I originally asked about the resonators. So maybe 2-1/2" pipe into Walker mufflers and a transverse in the rear. BTW I'm definitely not happy with the existing power (250 hp) and will upgrade to 400-450 hp as part of the restoration. This is all part of the plan for the "smooth and quiet" Chris Straub upgrade we discussed last year.