Basically long story short, I have erz test pipes, little rasp no hiss. I just installed an obx y pipe and let the hiss begin. It starts at the exact same rpm and the same way everyone else' does. I love the boost in power, makes a big difference. This hiss drives me insane.
picture of obx y pipe for reference 2.5" inlets, 3" outlet. Prime suspect is that transition from 3" outlet to 2.25" mid pipe
I was already going to piece together a custom exhaust, so I found some options I would like opinions on for conquer the hiss completely. Nobody has gone this route before to my knowledge so it will be a learning experience.
Here are the options
-- easiest and cheapest has a 3" inlet with either a 2.25 stock outlet, or 2.5" outlet for custom exhaust all the way back to the axle. Easy transition couple welds, who knows what it will sound like 2.5" with resonators or 2.25" exit to stock exhaust.
-- more expensive - 75$ for just the piece, then more complicated welding from the y pipe removing collector and having 2 pipes from the y converging to the x. this comes in 2.5 inlet or 2.25 same principal can go 2.5 and go custom mid pipe or 2.25 and match oem piping
Now ideally I would like to run the 3" inlet u pipe to the 2.5" outlet and continue that to the midpipe all the way to the muffler attachment at the axle. This seems like it would be the cheapest most direct rout to having a cat back minus muffler portion. I have 2 somewhat large resonators already that I would weld on each of the 2 sides of the u pipe to help with the sound Everything would match up right minus the 3" to 2.5" y pipe collector to u pipe collector which should be just fine.
Other option would be cut obx y pipe before collector and use the x pipe to connect y pipe to x pipe to mid pipe, again with resonators. This would cost a significant amount more money and my budget for this is 150$ (x pipes alone are like 75$ where u pipe is 15$
Simplest and cheapest temporary option would be u pipe from 3" outlet of y pipe and matching the 2.25" outlet to the rest of the exhaust.
My thoughts are, will this 3" transition from y pipe to mid pipe do the job to eliminate the hiss, and does it make a difference if I go 2.5 all the way back, or leave the 3" transitioning u pipe and connect to the stock exaust matching 2.25?
I will be replicated a number of after market exhausts so you can see what I am looking at, here are pics.
-- magnaflow which I could replicate through the mid pipe at a 3" transition from the obx collector to 2.5" outlet and add 2 resonators w/ the mid pipe at 2.5" This would be a y pipe back exhaust minus the muffler portion.
this option would chop the y pipe collector and install the x pipe for a dual 2.5" inlet and outlet to the mid pipe with resonators.
this example would be y pipe hacked and use no x pipe, connect the mid pipe then resonators without transition
Thoughts? Ideally I would like to have a y pipe back exhaust his free that sounds great and uses stock muffler section (for now).