I have ridden my bike with the exhaust from the cat back removed...it was extremely loud! It sounded like a V8 with open headers, for real! After about ten minutes of riding I had to quit because it was starting to give me a headache. musik20.gif
I know this is an old post, but can anyone explain what a spud is? Regardless, I'd sure love to have that exhaust. After hearing that sweet V4 without a can I almost couldn't go back. Can't be that much louder than the HD hot rods.
A spud is something that inserts into the outlet for the exhaust that restricts air flow, therefore reducing the noise level. Staintune, jardine and a few other manufactures offer these and the one being used in this setup looks like a slightly modified staintune spud.
An engine, unless designed for an open exhaust, requires some bit of back pressure to run properly. Most aftermarket exhausts are pass through but have an expansion chamber with packing (the can) to reduce volume but keep a minimal amount of back pressure. Even with an aftermarket can, you have to remap the injection to match or the engine will not perform correctly. Straight pipes can make serious horsepower, but the engine must be designed to use them. Harleys are not designed for this, nor are any other production bikes. MotoGP bikes have recently switched to this technology and are making upwards of 250 hp, so it does work. More or less, on a street bike, straight pipes are senseless.
And I am just curious when and where you have seen a HD "hot rod", most of the ones I've seen are very pigish look-a-likes.
Actually what I meant (at least in my head) by "hot rod" are the dudes that scream around on Harleys and just make a lot of noise. It's more the sound I was thinking of and not so much the look.
And I would agree with your last comment Chris. biggrin.gif
![[image: user posted image]](http://www.ozvfr.net/albums/Lyndons/aaa.sized.jpg){kind=link}