Modified my exhaust and...?

[akeenan]

Yesterday I modified my exhaust. It used to have 2 mufflers in the pipe and was cranking out a huge 82db. I replaced the middle muffler with a bit of stainless steel pipe. Now this is where i get confused.

when the car is cold it sounds basically the same as it did before maybe slightly louder...however when the thing warms up it "amazingly" becomes a lot louder. and i mean noticably not slightly maybe 2 times as loud..... does anyone have any conclusions to why this is so.....even on idle when cold its quiet but when its warm on idle it does the B B B B B B B......

anyone have any ideas? :confused:

[Emre]

I am not entirely sure if i understood your question but what is there to be confused about if you get rid of one of your mufflers and your car is louder...?

When your car is cold and you start it up, it will idle a bit higher than when hot. This would be enough to give it a different pitch in the noise. Once it warms up and settles down on idle you will hear the pulses more noticably and will sound as you described : B B B B B B ...

[akeenan]

every other "loudish" exhaust ive had have all been loud as soon as i start up the car. however this one only gets louder once the car is warm. at the same revs when its warm it is alot louder than with the same revs when its cold.

...i am not confused about why it is louder, as that was the point of taking out a muffler, but confused about the way it becomes louder when warm.

[Emre]

Well,

There is the technical explanation that metal expands when it gets hot therefore it would have more bore and volume, but it would apply to all systems on the market.

Plus, i'd doubt the difference in noise would be that noticable. Mine is certainly not that different from cold to warm.

[akeenan]

i thought as much about the metal expanding theory....trust me this thing gets very much louder once warm. Im rather experienced with aftermarket exhausts on my r33.....trust me it gets louder...

[Guest Oz Elitesport]

how loud is it with normal and hard driving? I want to do the same, but not at the expense of getting a head ache.

oz.

[akeenan]

well its like oranges and apples./...

it depends on your exhaust and the size of your mufflers.

the one i had on mine before yesterday was an exhaust for good flow and no noise, due to the epa a while back....but i got tired of no noise and took matters into my own hands.....

when its cold it would be under 90db for sure but when its warm i estimate between 89-91db.