Full straight midpipe ''iron''-sound?

[G-Ammo]

Hey guys...

Last tuesday i've redone my straight midpipe in full stainless steel.

Sound is awesome and I'm very happy about it, BUT:

whenever I put my foot down or come near 3000-4000rpm, I hear this iron-kinda sound... pretty hard to explain... like when you put 2 iron bars against eachother and shake them around (lol wut?).


hope someone knows what I mean!

But is it normal for stainless steel midpipe?


Thanks!

[Black_griffin6]

Did you go up in diameter? It could be so heavy that is banging against something. Some stiffer exhaust hangers might do the trick.

[Freestylin]

What you are hearing is "raspiness" due to the removal of the resonator. When you remove the resonator, you have nothing to reflect some of the high frequency sound waves created by the exhaust gas if that makes sense...

[G-Ammo]

Aaaah that explains it freestylin...! thanks :D And yes i did black griffin ;) but only 1cm bigger! ;) only got a 1.0 engine so.

[G-Ammo]

Is it possible to install a resonator back?

And where do I need to find one? Or how does it look like? and where should I install it?

[Bluevitz-rs]

install it back in the same spot it came from.

[G-Ammo]

Yeah but it also is used to be a mid-silencer... so If I put that back on... then it was useless to put in a straight midpipe.

are resonators also being sold seperatly?

[1.5]

you got a straight pipe exhaust to make it sound sportier but you dont want the sportier sound?

[G-Ammo]

yes I do... but the raspiness can be an ugly sound... :(

[trunkout]

I like the rasp of my straight pipe! BOSOZOKU!!

[1.5]

ahhh ok, are you sure the raspiness is just the metal type? I have raspiness as well but it only developed about 6 months after having the exhaust and mine is because its so low, I scrape holes in my exhaust. You are slammed as well and may have the same issue, it might not only be your exhaust material

[japle]

I also have that rasp in my exhaust system, 4 1 extractor, mandrel bent 2 inch stainless 0.2mm thick, a S-flow midbox, 2 inch all the way till the rear joint, ending with the blitz nur spec S-FLOW rear box, its nice, till you floor it, theres this metal knocking.... couldnt pinpoint wheres it coming from...

[CTScott]

That metal knocking sound is normal for the engine, but gets filtered by the resonator. If you run a Yaris engine with an open exhaust header (purely for fun) you will hear a horrible array of noises including that metal knocking sound.

If you read about what a resonator does, it is a precisely designed device which helps cancel out the worst frequencies of sound in the exhaust.

[Bluevitz-rs]

Did you use the proper spring bolts on the manifold connection?

What do the hangers look like?


Sent from my iPod Touch

[japle]

yes, i reused the original spring bolts in the manifold connection, incl. the rears as well, the hangers are all original...

scott, basically there is no solution for it?

[CTScott]

yes, i reused the original spring bolts in the manifold connection, incl. the rears as well, the hangers are all original...

scott, basically there is no solution for it?

The solution would be to add an aftermarket resonator to your exhaust.

[malibuguy]

Resonators are normally straight-thru factory and aftermarket. So adding one wont affect performance...if installed correctly and can even enhance scavenging due the cooling effect of the exhaust gases due the heat being dissipated thru the resonator.

I suggest the Flowmaster HP2...its a sorta hybrid straight-thru and works well at smoothing out the sound

[JimKellyfan]

I thought about replacing mine with a Cherry Bomb, the tube style glass pack in the middle, and the Vortex at the rear.

[malibuguy]

The vortex is a nice muffler with very high flow rates and good sound. Ive yet to install one on a 4banger so no idea what that will sound like.

I wish they made them in stainless i would totally run it

[G-Ammo]

thanks guys! but I actually got used to the sound... and it gives indeed that bosozoku sound / rally sound.

I'm low indeed but i dont scrape that much to be honest haha :P so its not that ;) its purely the sound of the engine without the resonator!

[JimKellyfan]

The vortex is a nice muffler with very high flow rates and good sound. Ive yet to install one on a 4banger so no idea what that will sound like.

I wish they made them in stainless i would totally run it

Yep, forgot about that factoid, been awhile since I went Maremont in TN.
But, the Vortex, I believe is 20 CFM less than straight 3" pipe.
Here is a quote from Dragzine, a rag I found when trying to re-research the exact CFM which I believe is around 500 CFM ish, I wanna say 568 and 548 (straight 3 inch pipe, then the Vortex) I had two of em on my old Caprice wagon, made it sound like a Vette, which really shocked......everyone who never heard that from a wagon before. When I need an exhaust, I am gonna try the glasspack in the middle, and the Vortex out the back...:cool:

...Here is the quote...


Paul Stevens, a Product Design Specialist for Cherry Bomb, has been in the exhaust aftermarket for over 31 years. He works in the Research and Development department, where he uses equipment like a super gauge to design and test new exhaust systems. “The super gauge machine we have here is used to measure all of our tubing and wire form and it is a very accurate machine. It is one of our key tools for designing exhaust systems under the car and then getting information to manufacturing.” Another tool Paul uses on a regular basis is the flow bench. “The flow bench measures the volume of air in cubic feet per minute,” Paul tells us. “We test mufflers, pipes and catalytic converters on this machinery.” The flow bench tells them that Cherry Bomb’s classic glasspack muffler flows about 510 cubic feet per minute of air, which is about 100 cfm shy of a straight pipe. That is some impressive air flow.

All of this research and development has helped Cherry Bomb expand its exhaust offerings beyond simple glasspacks, to products for the more discerning gearhead. Their exhaust offerings range from the Cherry Bomb Pro, Elite, Turbo, and the popular Cherry Bomb Extreme. The latest muffler they offer is the Cherry Bomb Vortex, which features special dividers and baffles which provide that Cherry Bomb sound, and a flow rate that nearly as efficient as straight 3-inch pipes, but without the deafening sound of an unmuffled engine.