catalytic converter removalel

Thinking about removing catalytic converter and replacing it with a Y and straight pipe and leaving the muffler as is. I'm hoping to improve sound. Any thoughts on this. It's an 81 so no omission is required.
Pat

It would be just slightly louder. I hollowed a cat once on my '84 auto. Marginal is the word that I would use to describe both the change in sound and performance.

Opening up and exhaust will not help if the exhaust is all ready big enough to handle everything that the intake can deliver.

If the engine has a significant amount of back pressure, then opening up the exhaust will allow more intake air and fuel to pumped through the engine. (remember the engine is just a piston pump)

This also has a lot to do with intake design and efficiency.
When I removed my catalytic convertors and bolted on the same style pipe, I believe the engine breathed better and that there was a bit more seat of the pants umpf
I have no numbers to prove this, but some others have posted their dyno numbers on the net.

The sound did get throatier for me.
I later (just this year) removed my muffler and installed the same open pipe set-up which is called a RMB (Rear Muffler Bypass) but its really just sticking a pipe in-place of the muffler.
I got a lot loader (when floored) and just a bit when cruising.
Some people complain of a loud drone (head ache type) with the RMB.

I will note here that.
When I engineered the H pipe to replace my cats,
I moved the Y where they join, further back to expose the flywheel housing.
I do not need to remove my exhaust to remove my flywheel cover any more.
You can see this in the picture below.

My experience is that earlier cars (through 83 at least) seem to benefit a great deal from exhaust upgrades. However, also check your manifolds. The stock ones on my 83 were horrible iron straws.....so I purchased a used pair of 85/86 and blasted and painted them. I then added the 3-in y-pipe and a new SS hi-flow Cat from Roger at 928sRus. Big difference in breathability and quicker reaction time. I would say the performance must be better as well but I have no numbers. It will rumble like a 32v car.....and this is with keeping the stock pumpkin muffler and rear pipe section after the Cat.

SO I would say definitely consider it. Just check and see if you model year exhaust manifolds are considered pretty good or not and if another model years might fit. I think it is probably a decent bang-for-the-buck upgrade. The last section stock section is likely 2.5 in, I bought a 3in upgrade but did not use a reducer, there is fairly little overhang where they match up. You could do it either way I think. I think also that my write up on it is elsewhere on the site somewhere. Just do a search.

Good Luck!

I agree with Michael. If you are considering a complete replacement of the exhaust, including the manifolds, you could see more significant gains. A lot of people have updated the manifolds to MY85/86 style and reported a boost in performance.

Thanks Guy's The response was great , but I'm not surprised. There sure is a vast amount of wisdom within an arms reach when there's a 928 owner's club you can turn to in a time of need..
Sincerely
Pat