So i decided to shy away from spending extra money on an exhaust since i heard what my friends gsr with a obx loopback sounds like. im plannin on running a 2.5 inch ID pipe with mandrel bends into the obx loopback.

I was also planning on using an e-cutout, but i am undecided on whether i should get it incorporated into my header when i do that, or have it after the cat on my exhaust. i am concerned that the e cutout could create turbulence in the exhaust unless i put the valve closer to the outside of the normal muffled pipe, if that makes sense. even if i did have the valve close to the outside of the pipe there is still going to be an unsmooth area on the inside where it meets, which is why i was steering away from doing it on the header although that was my first plan.

my questions were
first what is a suitable wall thickness for an exhaust... comprimising between thickness (for better sound quality, and durability) and also thinness (for being lightwieght). would .22~ inch be pretty good thickness?

second what material is the best for the price... stainless steel?, mild carbon steel? is aluminum even any good for an exhaust? i live in california so im not too worried about rust. my friend has access to a tig welder so i should be able to choose whatever material i want that is weldable with tig. i also trust his welding ability.

and third would it be best to run the e-cutout in the header, or after the cat? and is an e-cutout even a very good idea, like does anyone have problems with them opening on accident, if anyone knows a good company to buy them from (with a reasonable price).

also right now i am running a 2 inch pipe out of a cat with a turn down on the end so its really loud and my car always smells like gas, and im sick of it. i figure anything with a muffler, especially a loopback is going to be a hell of a lot quieter than what i have now. i do like the way it sounds unmuffled in vtec though, thus why i was planning the e-cutout.

my setup now is just a jdm b16a in a eh2, but i plan on building a b20 block with high compression, and eventually running a stroked and sleeved 1.8 block, thus why i am getting such an oversized exhaust. i would rather not have to go through this all again when i do finish the build.

anyone's opinions are appreciated, i dont think i am violating any rules here since i searched for a while but couldn't find information specific to exhaust wall thickness. ill go search about e-cutouts right now since i guess i neglected to do so.