stevieturbo

403ci LS2, YSi blower etc, so making decent power.

I want a new full true dual 3" exhaust system made. Space is quite tight under the car, but I want a full compliment of 2 middle mufflers, and 2 rear.

This makes fitment of an X-pipe quite awkward due to lack of space under car.

So would it really matter between an X or an H/balance pipe ?

When constructing an X pipe. Does it matter that some designs actually reduce the overall CSA in the middle of the X compared to two full pipes ?

I do use the car on a regular basis, and the noise when crusing around 60-70mph is getting tiresome, hence I want to add larger mufflers in the middle ( which is more or less where the X is now )

But I want it to have minimal impact on performance.

Is an X design that has the full area of 2 x 3" diam pipes, plus the X connection better ? ( ie no reduction of CSA with the X )

Does placement of the X or balance pipe matter ? It will have to be after the middle two mufflers for the new exhaust.

I intend using 2 x 9"x4" oval Magnaflows in the middle, and retain the existing 8"x5" rears.


Dual 3.5" would be nice...but that would be getting very very expensive. Could maybe do 3.5" from collector to first mufflers though if it was of any benefit. Or at a push, 3.5" with custom mufflers, a balance pipe right up the the rear axle.
They would have to step down before they passed the axle though to 3".

Any thoughts welcome.

Thanks

Stevie

Cheatin' Chad

iTrader: (3)

Did you post @ Gofastnews as well?

There is a good post that David Vizard is involved in there already.
http://www.gofastnews.com/showthread...mination-Boxes

stevieturbo

I did indeed.

I had read about the termination boxes, but they seemed to require certain sizes etc.

Given the silencing I want to take place, and the shape of my car, I really doubt they could be fabricated for my car.

The images seem to require a quite long straight termination box. Due to the shape of the undnerside of the car, the fact I run a 2 piece prop with centre bearing, and compared to American cars, mine would be fairly short overall....

I dont think it would be possible. I'll just have to stick to more conventional routes.

stevieturbo

Although that does assume the TB is a longish straight affair.

If they simply need to be a very large box of open space, something could be possible. But they would then be taking up the space of silencing...and my main goal is to make the damn thing quieter.

Cheatin' Chad

iTrader: (3)

Vizard stated 8-10x the volume of one cylinder. I don't recall him dictating long or wide...

stevieturbo

True, but his do appear to form long and wide, and also interconnecting both banks.

2 large chambers could possibly be formed shortly after the collectors. Not sure if they could be the required volume or not though. Having them interconnected might also be possible...albeit in a strange way.

And would one large enough chamber be ok for both collectors to enter into ?

or one one chamber per collector, then exitting a normal exhaust be better ?

And I still need room for the mufflers !! Such chambers would make that impossible. Or would these chambers themselves provide noise reduction ?

Cheatin' Chad

iTrader: (3)

This can be made a lot simpler. There are a lot of race cars that don't connect the exhaust pipes at all. I don't think the C5R did.

If I were you I would make a compromise and do what wohat tould get the most benefit with the least grief. That to me sounds like an H-pipe set-up. I think if your engine is set-up properly power will be the least of your concerns.

Try reading this:
http://www.eng-tips.com/viewthread.c...=189289&page=8

Cheatin' Chad

iTrader: (3)

Magnaflow has a dual/dual muffler that has an X pipe inside of a perforated core straight through muffer. This would give you your X pipe and your intermediate muffling http://www.magnaflow.com/02product/s..._universal.asp

stevieturbo

There is no room in the centre of the car as thats where the gearbox/driveshaft run.

Cheatin' Chad

iTrader: (3)

Doesn't leave many options then.. I'm back to suggesting an H-pipe.

http://www.fordmuscleforums.com/all-...pe-h-pipe.html

btw: I remember reading an article suggesting the crayon thing mentioned in that thread.

You could read this: The Scientific Design of Exhaust and Intake Systems' by Phillip H. Smith’

OR

if you're real serious I'd suggest contacting

vince@burnsstainless.com

They deal primarily with header design BUT should be able to help with entire exhaust systems.

stevieturbo

Anywhere in the US is several thousand miles away.....so reading is good....fabricators may not be so helpful lol.


If the termination box is as simple as it sounds, I'm giving it serious thought.

He does seem to suggest that if for example its an 8.0 engine, then you need 8.0 litres per box, per side of engine.

Although the box itself doesnt actually have to be an empty chamber. He seems to say that some of the chambered style mufflers whilst they have baffle plates, do actually appear as an open chamber to the collector.

So if this is actually true, then a chambered style 9x4x14 muffler would actually have the desired 8.0 litres of volume per side.

Wish more people out there had done this stuff !

Adrenaline_Z

I don't think you'll find many examples of termination boxes in real-world
applications. They are heavy, awkward fitting and expensive.

You can design a loss-less system without the need for termination boxes,
but it will take more effort. The only disadvantage is your sound level remains
too loud.

Are you opposed to using electric cut-outs? This will allow you to insert the
cut-out at the desired tuned length and open them when you require extra
performance, and close them when you want the gasses to flow through the
muffler.

If you want a good read on designing exhaust (and intake systems) for your
car, check out: "Scientific Design of Exhaust and Intake Systems"

It's fairly advanced, and gets deep into mathematic equations.

stevieturbo

The car must remain silenced at all times. Cutouts are not an option. Some places I race are getting quite tight with noise levels. So I want a system that covers all issues. Noise and peformance.
Although I do actually hate the sound of most open collector exhausts. Unless they have a few thousand HP. Then they're cool.


Does the logic that a 9" x 4" x 14" chambered style muffler with a volume of some 500ci not mean that it actually is a viable termination box ? That is how I am reading the logic of it ?

No, it may not silence as much as I want, but I think I could then squeeze a pair of 9x4's ( or failing that a pair of 4" round 14" long ) glasspack mufflers later, as well as the existing 8x5's currently in there, after the termination boxes ( or mufflers used as TB's )

I'm not overly concerned about weight. As I am paying to have this built, and it will be top quality. I want it to be the last system I ever fit to the car.

Adrenaline_Z

I'm not so sure a muffler of that size will behave like a termination box.

The first thing that comes to mind is the muffler will impede flow.

The termination box does not present restrictions to flow, and uses phase cancellation
to attenuate sound.

If I'm not mistaken, the tuned point for a muffler is different from a termination
box where the entry of the termination box is the tuned point, as opposed
to "somewhere inside" the muffler.

The internal design, and placement of the baffles will dictate where this
tuning point occurs.

stevieturbo

Reading this almost makes me think otherwise

http://www.superchevy.com/technical/...exh/index.html

Whilst visually what appears to be free flowing to us....doesnt always work out that way in terms of the flow the engine needs to see. If the chambered style is open enough, then it will be seen as zero restriction.
Obviously I am referring to a design that does flow, and doesnt have mega restrictive chambers.

I do beleive that the magnaflow one I refer to is pretty open and free flowing.

Adrenaline_Z

That is correct, but you mentioned earlier that you wanted to keep the
noise to a minimum? The muffler you suggest is still quite loud.

I guess I'm a little confused as well because you seem to imply that you
want to use the Magnaflow muffler(s) as the termination box?

Lastly, what I meant by tuned point is outined in the article you linked
in figures #6 and #8.

ie:

When a pipe terminates in a termination box, the tuned length occurs
at the end of the pipe where it meets the box.

A muffler's tuning point may occur within; just be cautious where you
mount these items because it will effect the tuning of the system.

Your tuner/builder should have a program (like Pipemax) to determine this
optimum point.

stevieturbo

As I say, these will not be the only mufflers.

Just the primary pair. At best, there will also be another pair of 9x4 glasspack Magnaflows, and 8x5's at the rear.

original thought was to add the 9x4 glass pack as the primary pair, with only the 8x5 rears thereafter.

But it almost seems like if I can, there will be no downsides to using the chambered styles up front, and trying to squeeze the additional mufflers in somewhere else.

The tuned length bit etc etc only seems to apply to a little mid range. That isnt a massive concern. I just want to ensure top end performance is as good as I can achieve with a quiet system.

Programs and ideals are all good and well. Regardless of what they might say, there is only limited space available to achieve any installation.

Adrenaline_Z

THat's what I mean then. The muffler you want to use as the 'termination box'
doesn't have the volume to act like a termination box.

Even though the outside dimensions appear to be proper, the internals of
the muffler you describe is displaced by material.

These (or similar design) will not work:

stevieturbo

Reading teh article above, it would seem to suggest that



could perform a similar function. If not as a TB but still more beneficial near the collector due to the sudden increase in volume, than the straight through design. Which being straight through looks the better option, but in reality, it isnt.

Which is why I'm considering steering away from the latter design as primary silencer boxes.

Adrenaline_Z

If tuning for upper end power, then yes...placing the TB 'near' the collector would
create a tuning point for the upper range. The distance is something your
tuner will calculate.

I'd like to know David Vizard's professional assessment on any type of muffler
acting as a termination box; from what I've read, and based on the science
it just doesn't seem to work.

We'll see if he responds to your question on GoFast.