Can you make the engine sound better?

[lestat13]

Either that or we need to get Travisdee over here to hook us up with VQ swaps.

oooooooooooooooo!

I personally love the way the the VQ in the 350/G35, the VW R32, and STi motors sound.

Yum!

 

[hectik1]

ok, so far the only descriptions for the SRI are words like "vacuum type" and "air sucking."

these are hardly sounds that i would consider nice and aggressive. i listened to several youtube videos but the sound recording sucks (or it's the fault of my teeny computer speakers), so i can't really get a good idea of what it sounds like.

These are nice and aggressive sounds when coming out of a turbo car.(thumb)

Can't beat the sounds of high boost Supras and Evos.

 

[mrjoshyman]

I know exactly what you're saying, it sound blurbly kinda like a Subaru. The cause is the stock turbo manifold; all of the runners are really unequal in length. Change your turbo exhaust mani to a custom equal length unit, and the engine will sound perfectly uniform.

why do they make the length of the runners unequal? is there any advantage 2 that?

 

[lestat13]

why do they make the length of the runners unequal? is there any advantage 2 that?

Ideally the exhaust pulses are going to "pull" each other through the exhaust system if setup correctly. This setup might be used for better timing that way?? I know I saw this somewhere on the internet a long time ago when the integra guys were arguing about which size exhaust to run.

 

[imac]

Ideally the exhaust pulses are going to "pull" each other through the exhaust system if setup correctly. This setup might be used for better timing that way?? I know I saw this somewhere on the internet a long time ago when the integra guys were arguing about which size exhaust to run.

yea, it has to do with the timing of when the cylinders fire and stuff like that. if i remember right, it's supposed to keep the cylinders from dumping their gasses into the exhaust at the same time. if it's timed right, there's a more even distribution of when gasses try to pump through, not all at the same time, causing excess backpressure.

and the "pull" thing youre talking about is a scavenging effect, which has to do with pressure differences and using them to suck the exhaust out more effectively and efficiently. there is a fine line between getting enough scavenging effect and having excess backpressure, though.

 

[lestat13]

That's exactly it. I remember a website with a video, but it wasn't howthingswork. nice job!

 

[dkswim]

on forced indunction cars the equel leagth is not that inportant its more important to get it out thats not ta say equel leagnth dosnt help. on na cars it a lot more important

 

[techspeak]

why do they make the length of the runners unequal? is there any advantage 2 that?

There is no advantage at all. The unequal length nature of the manifold is sadly for packaging reasons alone. The timing of unequal length manifolds sounds blurbly. In this case, 1 & 2 cyl ex. runners are significantly shorter and 3 & 4 cylinders are longer IIRC. Imagine it like 4 trumpet players, two of the players play one note when its their turn and the other two play a slightly lower note when its their turn. The result (when they go REALLY fast in sequence) will sound gnarly, even though they play at exactly equally spaced intervals. Thats because of the different valving per two trumpets. Likewise you have different tuned exhaust notes per cylinder at the turbine inlet (and subsequently out the muffler).

Like dkswim said though, unequal length manifolds dont really impact performance on turbo applications. Unequal length runners on an NA setup will result in uneven scavenging properties among the cylinders, which is a bad idea.

 

[phillyb]

is it only me or did putting on the stiff motor mount changes the exhaust tone ...

I think it did, I thought I was the only one that thought that....

me too. even one of my friends asked me though. the mm also makes the car feel heavier.

i agree, it makes it deeper jussst a bit.

Another vote for motor mount changing exhaust sound.

Yeah a little deeper and more noticeable at idle, I really like it, makes the car sound more aggressive. On top of that I put my cobb sri on about a week ago so now theres even more great sounds coming from the car.

I don't think it's the exhaust you're hearing, I would think that installing the MM would increase the engine resonance of the cabin as you are passing more vibration to the body.

really???
hmmm...maybe you are right. there is definitely more noise

 

[dparm1984]

My car didn't change much in tone when I threw the Mazdaspeed CAI on...even running it short-ram it's still not much louder. Only difference is I can now hear a bit of the factory bypass valve.

Your best bet is going to be something like a catback exhuast, or even cutting out part of the factory one.

But then again, noise does NOT equal fast...there's plenty of whisper-quiet cars that are scary-fast. Noise is just a good way to get challenged to races, or worse yet, attract cops.

 

[nextcar]

My car didn't change much in tone when I threw the Mazdaspeed CAI on...even running it short-ram it's still not much louder. Only difference is I can now hear a bit of the factory bypass valve.

Your best bet is going to be something like a catback exhuast, or even cutting out part of the factory one.

But then again, noise does NOT equal fast...there's plenty of whisper-quiet cars that are scary-fast. Noise is just a good way to get challenged to races, or worse yet, attract cops.

thanks for the input. yes, i think i'll be fine with the cobb sri once they ship it. i don't wanna mess with the exhaust because it would likely increase the noise at idle and cruising speed.

 

[dparm1984]

On the contrary, people have said that the stock system resonates badly at about 3000rpm...I would agree. Some of the aftermarket systems have better resonators that dampen this.

 

[Rotus]

On the contrary, people have said that the stock system resonates badly at about 3000rpm...I would agree. Some of the aftermarket systems have better resonators that dampen this.

How would a better resonater make the exhaust slightly wet?

 

[Kindred]

^^ I chuckled.