When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
On headered sidepipes the collector is like 3" and goes into a 3" pipe.
BUT the muffler is in there isn't it? Is there something wrong with this picture? Seems like the side pipe is a transition from 3" down to 2 with a bluff transistion instead of a cone.
Stocks neck down to less than 2 inches in the muffler area. Hooker sidepipes are 4 inches, however, if you use Hooker mufflers, the internal pathway is also less than 2 inches. This is why a good number of folks are going with the STS or chambered inserts.
Brand doesn't matter. I'm talking about headers being dumped into sidepipes like they were open.
Stock sidepipes with headers have this transition
On the STS ones it looks like the center is blocked? Even if it isn't the spiral seems to be a lengthening of the exhuast pipe. Better than the others.
I hear the sound is pretty nice, although I've never heard them. The STS spiral is not a continuous spiral, but it does appear to lengthen the path by quite a bit. The chambered inserts are straight through, but word is that they are the loudest. I've ordered the STS baffles. By the way, you can drill out the center cap if you need to...
I removed the center cap with my old 355, but needed to reinstall it then later drilled holes into it to quite it down some with my new engine. It is nice to be able to tailor the sound level some with them.
Here is my 355 idling with the STS sidepipe mufflers: Click here.