Dual Exhaust

[Nimble]

What have I started?

Chris, that pic is regoshdarndiculously hilarious!!!

[Yaris Revenge]

Is Vanilla sportin' a woody in that pic or what???

Looks frighteningly similar to Max Headroom there...

~YR

[elsteverino889]

Dual exhaust FTW!

[Nimble]

incorrect. ftl.

[Spades]

Ok, backpressure and exhaust velocity both add to decreased HP...they both affect eachother but are indipendant. Back pressure is how much restriction there is in the pipes, it measures how much it takes to get the exhaust through the tubes. Exhaust Velocity is how fast the gasses move through the tubes.

While low back pressure is good for horse power, there needs to be a little bit there or most of the computers in newer vehichles do not adjust properly to the changes in pressure.

Exhaust velocity is what is affected most by splitting the exhaust. you can get 4" piping all the way back to the mufflers and 4" mufflers, and you will have no back pressure, but on the other hand, because you split the exhaust flow your exhaust velocity goes down.

It has been proven on the dyno...single vs dual exhaust on 4cyl cars...single wins every time.

If you want dual exhaust, more power to you! Just keep in mind you are sacrificing performance for style.

Yes steve, dual exhaust will work with a turbo...heck, it will work with anything...But with a turbo you would notice even more power gains with a single exhaust set up.

P.S. maybe I do need more drugs so it will help me when I try to explain stuff that I only think I know about.

[Sabretooth]

FlameYaris...why photoshop when theres youtube...


http://youtube.com/watch?v=2HxvS8knQJs

[heylookitsjames]

It seems to me that due to laminar flow, two smaller pipes with the same cross sectional area as one larger pipe would infact have higher gas velocity (this can be seen when solving the Reynold's Number equation for mean velocity and using an Re of 2300 it can be seen that L, or "characteristic Length"... in this case, the diatmeter of the pipe, will result in an smaller laminar flow value). Also, if they were fused/jointed correctly, they could be as uinrestrictive as well. In addition, scavenging effect (effectively having a wave of low pressure interlope its way back into the combustion chamber that aides the successive induction charge) is more pronounced on smaller diameter pipes...

/This being said, I think that twin exhaust would look kinda dirty...

[Black Yaris]

whatever happen to that photoshop of some zoomies coming out the wheel wells with flames coming out?

[Doc Zaius]

Originally Posted by heylookitsjames

It seems to me that due to laminar flow, two smaller pipes with the same cross sectional area as one larger pipe would infact have higher gas velocity (this can be seen when solving the Reynold's Number equation for mean velocity and using an Re of 2300 it can be seen that L, or "characteristic Length"... in this case, the diatmeter of the pipe, will result in an smaller laminar flow value). Also, if they were fused/jointed correctly, they could be as uinrestrictive as well. In addition, scavenging effect (effectively having a wave of low pressure interlope its way back into the combustion chamber that aides the successive induction charge) is more pronounced on smaller diameter pipes...

Holy hell! Fluid mechanics? Must be an engineer!

[sf180th]

Originally Posted by heylookitsjames

It seems to me that due to laminar flow, two smaller pipes with the same cross sectional area as one larger pipe would infact have higher gas velocity (this can be seen when solving the Reynold's Number equation for mean velocity and using an Re of 2300 it can be seen that L, or "characteristic Length"... in this case, the diatmeter of the pipe, will result in an smaller laminar flow value). Also, if they were fused/jointed correctly, they could be as uinrestrictive as well. In addition, scavenging effect (effectively having a wave of low pressure interlope its way back into the combustion chamber that aides the successive induction charge) is more pronounced on smaller diameter pipes...

/This being said, I think that twin exhaust would look kinda dirty...

[Spades]

hrm...two pipes may be more efficient at expelling gasses than one larger single pipe...however, maybe I am way off...but doesn't splitting the flow hurt exhaust velocity? If it does not, I formally apoligise to anyone I may have misled.

[heylookitsjames]

Originally Posted by Spades

hrm...two pipes may be more efficient at expelling gasses than one larger single pipe...however, maybe I am way off...but doesn't splitting the flow hurt exhaust velocity? If it does not, I formally apoligise to anyone I may have misled.

No... you are actually probably correct... hence my "Also, if they were fused/jointed correctly" statement...

The real trick would be point of fusion between the two pipes, this is for sure.

[elsteverino889]

That video was weird, kinda freaked me out

[eTiMaGo]

Just tried this in photoshop out of curiosity, it could actually look pretty decent in person... Piping would be difficult indeed, but if you went so far as to remove the bump of the spare wheel, that would give a lot of space...

Something to think about...

[Black Yaris]

nice

[ChinoCharles]

It would look sick on this car.

James, what you're saying is two pipes with a 1.125" diameter would perform better than a 2.25" exhaust with a single pipe? Dare you to try it.

[elsteverino889]

That does look nice etimago but let say a boosted yaris and wanted a dual exhaust would it be better than a single or dual exhaust upgrade

[eTiMaGo]

Well I'm not thinking of running two pipes off the engine, just the standard single one, but splitting it in two at the axleback level. Although, what I think would be an ultimate setup is to have one performance-oriented, noisy exhaust on one side, and a quiet one on the other, and switching between the two with some kind of butterfly valve at the junction I think Porsches and other high performance cars use an automated setup similar to this to pass noise regulations...

But anyway this is just a silly concept at the moment!