Muffler Delete

[Silver Streak]

Hey all, I'm playing around with the idea of replacing the exhaust from the axle back with just a pipe. I do however have a couple of questions. Have any of you tried this, and how was it for daily driving? My second question is does anyone make a bolt on pipe to replace the rear section so it would be easy to switch back if it proved undesirable ?

[IllusionX]

It's going to be loud.

however, i've heard a yaris with a muffler delete, but the owner also did a split, about 2ft back, and loops it back into the pipe about 1ft before it ends. Not sure if you understand.. this will muff some of the noise. and it did sound good.

[tooter]

It's going to be loud.

however, i've heard a yaris with a muffler delete, but the owner also did a split, about 2ft back, and loops it back into the pipe about 1ft before it ends. Not sure if you understand.. this will muff some of the noise. and it did sound good.

That's a valid principle. :smile:

The sound waves are split up so that part travels another route which puts it out of phase with the rest. Then the out of phase waves are recombined and tend to partially cancel each other out. There are some mufflers that do this internally...

http://www.burnsstainless.com/images/technology/Mufflers/Figure_6_July_2011.jpg



...and even some that do it with external pipes.


http://www.mufflermall.com/images/nt1602.gif




Greg

[IllusionX]

https://www.youtube.com/watch?feature=player_detailpage&v=Hqiv_3Pqv_E#t=178

https://www.youtube.com/watch?v=gilFGnewu6E

[Silver Streak]

Thanks Illusion I had seen these, but still hard to tell how much louder it would be than my Trd when driving.

[tooter]

https://www.youtube.com/watch?feature=player_detailpage&v=Hqiv_3Pqv_E#t=178

https://www.youtube.com/watch?v=gilFGnewu6E

I think it's funny when people put their phones in the worst possible place, directly in the line of fire from the exhaust pipe, and it knocks them over! :laugh:

https://www.youtube.com/watch?v=YectX1tadpg

[JudgeM]

I removed the catalytic converter from my Corona and that made a difference to the sound and performance while keeping the stock muffler.

[ezhacker1]

Does this help? Taken from 3ft away, revving to 3100rpm. After SeaFoaming the engine, there is no drone at highway speeds. (I cant prove this, but thats the only change during the time between the going from the Res-back to DC sport back to the Res-Back)

DC Sport Axleback: https://www.dropbox.com/s/h8l28gm71lg812e/2.%20DC%20Sport.wav
Resonator Back (straight pipe): https://www.dropbox.com/s/iesbvnv8xsc8edk/3.%20Res%20Back.wav

[Silver Streak]

EZhacker1, I tried to play it and it says there's nothing there.

[cali yaris]

It's not that loud, but it is louder than stock. I don't know an off the shelf replacement pipe -- you'd need a flange and some bent pipe, because the flange from the midpipe points up t the undercarriage.

[ezhacker1]

EZhacker1, I tried to play it and it says there's nothing there.

Fixed the links. I simply just sacrificed my stock muffler, and had a pipe welding and bent to center exhaust. (Not ideal, for flow, but cheap and works).

DC Sport Axleback: https://www.dropbox.com/s/h8l28gm71lg812e/2.%20DC%20Sport.wav
Resonator Back (straight pipe): https://www.dropbox.com/s/iesbvnv8xsc8edk/3.%20Res%20Back.wav

I plan to redo the testing. The recorder had bass cut on... so doesnt show the whole audio dynamic range. Hope to do more exhausts from people around me.

[tooter]

The straight pipe actually sounds pretty dang good! :thumbsup:
Here's my Magnaflow exhaust with a resonator tip added to smooth it out more.

http://www.youtube.com/watch?v=FL4CcjF8Z18

[Silver Streak]

Sounds good you guys.

[Bluevitz-rs]

I've done it before. Made my own straight pipe from hacked-up bits from a spare Borla axle back muffler I had for my Echo. Sounds Ok, but a lot louder than running the Borla. I ran a header, stock mid pipe and the straight pipe. Sounds like touring car, if you've ever heard one on track. Matched with my 6 speed close ratios transmission it sounds pretty cool pulling on the the highway, but gets old fast, and I think it made less power than running the Borla for some reason.

[JustPassinThru]

I've done it before. Made my own straight pipe from hacked-up bits from a spare Borla axle back muffler I had for my Echo. Sounds Ok, but a lot louder than running the Borla. I ran a header, stock mid pipe and the straight pipe. Sounds like touring car, if you've ever heard one on track. Matched with my 6 speed close ratios transmission it sounds pretty cool pulling on the the highway, but gets old fast, and I think it made less power than running the Borla for some reason.

Yup.

The engine is designed to run with, and the microprocessors tuned to, running with a certain level of back pressure. Drop that back pressure and conditions are out of design specifications; and depending on the computer controls, it might read it as an abnormality and retard spark or enrich fuel. Lower performance.

[Bluevitz-rs]

Well the Borla is a straight through glass pack type muffler so the back pressure should be the same on both pipes. I have a feeling i didn't put the connection together tight enough and was causing some vibration through the exhaust causing the knock sensor to pull timing. It was mostly in the lower RPM range.