^Yes, all correct. I was thinking it would be a bit louder with the bypass closed but not much difference vs the high flow cats.
I recall someone here briefly and oddly mentioning hollowed out stock cats have a different tone vs a simple strait pipe. It got me wondering for a bit. My car came with hollowed out stock cats. I still have the oem y-pipe. With the bypass wired open and capristo 3, I felt the car sounded insane. High pitch in all range all the time. Not sure if there's any validity to the hollowed cats claim.
indeed there is a difference in sound between a hollowed cat and a straight pipe.. ive ran both setups.. hollowed cat sounds nice.. better then functioning cat.. but because of the oval shape, it acts like a resonator, disrupting the flow of exhaust from header outlet to exhaust inlet ( smaller diameter, to bigger, to small again). in my case.. at idle, little to no difference between empty cat and straight pipe. but at full throttle, sound difference was is very noticeable. crisp, more clean pitched sound..
It's 2.25 at the inlet (to slip over 2.125 header outlet). Steps down to 2.125 at the outlet to accept v-band flanges for the muffler.
Interesting! Thanks for the feedback. Just to be clear, are you saying you prefer the sound of a hollowed out cat vs. a straight pipe?
I swapped my Tubi straight pipes for the OEM catalyst - they soon broke down and I punched them out. There is indeed a difference in sound between a test pipe and a hollowed out cat. The straight pipe is more crisp and raspy sounding. The hollowed out cats have a different sound and I think I would prefer the sound of cats on the car TBH. I didn't like having a decatted Y pipe for the same reason. It's more crisp but loses something.
sorry.. ive ran stock cats, hollowed hyperflow cats and test pipes.. I prefer the test pipe setup for sure.. only thing I haven't tested is a ypipe
Ok. So I guess we're in agreement hollow cats = not good. Test Pipes = better. I've got hollowed cats on the car and a pair of straight pipes in storage. Just wondering which one I should be using when the time comes.
348, I run 2.5 ID tubes with 2.5 ID cats and flows better then hallowed out stock cats. Better mid and high rpm Never dyno'd with test pipes
