FAQ: The Exhaust Thread

charlieRobinson wrote:

Like I said, cat was non existent prior to DP install.
All the welds are good, no leaks.
Only difference is the O2 sensor emulator is now in place.

Could that be it?

No, that's not it. BTW, that emulator is going to be useless after I tune that thing. Again, we'll look at it on Sunday. Quit worrying about it for now.

No, the emulator won't cause exhaust fumes.

I think you need to back up and understand what you did by removing the cat. The cat converter's job is to make the exhaust "cleaner" by converting harmful smelly stuff into CO2 and water. When you take that out of the exhaust system, you are now going to have a more smelly exhaust because it's just blowing right through.

+/-1% LTFT doesn't mean anything. ALL cars have this much variance in daily use.

AA, like I said. The cat was hollowed out when we cut it. In other words it had no function before we installed the DP.

Were you aware the cat was gutted before you opened it up?

AA wrote:

Were you aware the cat was gutted before you opened it up?

Nope.

hey guys im new to the forums and have a 1996 l67 riviera that i will be doing some exhaust modifications on soon. i do realize that the 3800 sc doesnt sound good in general but for some reason the grand nationals seem to sound deep and throaty, i know that a turbo will soak up alot of noise compared to a supercharger but these are essentially the same motor just at a different angle. so i guess my question is there any way to get these cars to sound like a GN?

Unfortunately, theres not many ways to make a 3800 exhaust note worth hearing. I've seen all different setups and never heard one I like. With a cam, headers, or both, I've heard some better sounding, just not for me.

There is an exhaust clip thread if you want to get an idea of some different setups people have tried. Check it out:
https://rivperformance.editboard.com/t6854-exhaust-sound-clips?highlight=exhaust+clips

Also, the 3.8 used in the grand national was essentially a completely different motor than the 3800. The displacement causes alot of people to think that parts might even be interchangable, and I was curious about that too. I think the Grand Nationals sounded so nice for a V6 because it was a SBC with 2 cylinders cut off. I read that the manifold, heads and valve cover bolt patterns were even the same, minus the extra set for for the 7th and 8th cylinders.

Theres always setups people havent tried so dont hesitate to try something new if you have a good feeling about it. Maybe you'll come up with the ultimate solution to the exhaust note on a 3800.

My biggest aggravation the sound is that almost any exhaust you put to it has that nasty sound like a bunch of bumblebees in a tin can ... and on top that nasty cap gun pop when its coming down AA had the factory and removed the cat and it sounded really good but a catless is almost illegal in every state so look at your state emissions laws.. and borla xs sound kinda good on the 3.8 and I got my eye on a setup if it works im gonna post it

h20man wrote:

hey guys im new to the forums and have a 1996 l67 riviera that i will be doing some exhaust modifications on soon. i do realize that the 3800 sc doesnt sound good in general but for some reason the grand nationals seem to sound deep and throaty, i know that a turbo will soak up alot of noise compared to a supercharger but these are essentially the same motor just at a different angle. so i guess my question is there any way to get these cars to sound like a GN?

And to answer that question for the GN was a different engine I inquired about that along time ago it came down to displacement and valves so we

th3fr4nchi5e wrote:

Also, the 3.8 used in the grand national was essentially a completely different motor than the 3800. The displacement causes alot of people to think that parts might even be interchangable, and I was curious about that too. I think the Grand Nationals sounded so nice for a V6 because it was a SBC with 2 cylinders cut off. I read that the manifold, heads and valve cover bolt patterns were even the same, minus the extra set for for the 7th and 8th cylinders.

Nope, it was the Small Block Buick, not the SBC.

yeah im leaning towards what johnny said i think ill try borla they seem to be a pretty quiet muffler, my dad thinks though that flowmaster will sound good though. My other car is a mitsubishi 3000gt and it sounds great straight pipe to just a flowmaster then again a much different smaller engine......

LARRY70GS wrote:

th3fr4nchi5e wrote:

Also, the 3.8 used in the grand national was essentially a completely different motor than the 3800. The displacement causes alot of people to think that parts might even be interchangable, and I was curious about that too. I think the Grand Nationals sounded so nice for a V6 because it was a SBB with 2 cylinders cut off. I read that the manifold, heads and valve cover bolt patterns were even the same, minus the extra set for for the 7th and 8th cylinders.

Nope, it was the Small Block Buick, not the SBC.  

Whoops! Yes, that is right. Larrys always on top of things!

why is there so much dis on the 3800's exhaust sound? I think it sounds fine stock and can be greatly improved with exhaust mods. See Abaddon's Riv for a great example.

The 3800 II can for sure be made to sound great. No doubt about it.

I haven't really heard any GN's that sound a lot different/better than these transverse 3800's and I would think it'd be much easier to make them. There are some really sexy sounding aussie longitudinal 3800 cars though that aren't even turbo.
W-body headers only make it sound worse IMO. Most of my exhaust systems sounded decent up until headers went in and then I started getting picky because I didn't like it. The exhausts I've settled on after than were quieter and more unusual but I do like it now. I'm actually not a fan of stock exhaust with headers either. Most of the time, it still seems to have the unfavorable noises of any headered 3800 but without the toughness factor.

Well so far I have only heard about 5 cars total thats sounded good. In my opinion tho which 2 were turbos and one was super cammed sounded like a corvette. And the 2 on here with take home modifications but my personal experience and being very cautious with these motors are not to drive anyone away

With all the new members joining, by all means please feel free to not just post the 1st thing that pops into your head. If you don't know why the old 3.8L V6 is different than the 3800, don't answer. There's a lot of misinformation in this thread, and it's popping up in others as well. The forum is a searchable database, and flooding it with garbage helps no one.

To answer the OP's original question: No. Nothing you do will get the 3800 in your riviera to sound as good as the 3.8 litre turbo in the Turbo Regals.

Jason wrote:

With all the new members joining, by all means please feel free to not just post the 1st thing that pops into your head.  If you don't know why the old 3.8L V6 is different than the 3800, don't answer.  There's a lot of misinformation in this thread, and it's popping up in others as well.  The forum is a searchable database, and flooding it with garbage helps no one.

To answer the OP's original question: No.  Nothing you do will get the 3800 in your riviera to sound as good as the 3.8 litre turbo in the Turbo Regals.

Put a address on it next time

ill just have to try my best and figure out what setup sounds good

I have a 1996 riviera to, where are you getting your exhaust set up? I want to by a full 3inch system any advice, I can install myself.

Right now I'm leaning towards doing a 3in catted downpipe, to 3in piping going to a glass pack then a single borla muffler with a turn down tip. Figured ill save weight without duals plus easier install but that's up to the muffler shop

I think another thing to consider that many do not think about is the thickness of the piping used for the exhaust parts. The thickness of the pipe walls make a difference, but it is hard to find different thicknesses. Perhaps someone here knows where to look for exhaust piping that comes in different wall thickness.

All I say is ask your self one question.. What are you doing it for Performance, Sound, or just cause you can?

Well I don't really care too much about sound I mean I don't want it to have that tin can noise but I'm mostly in it for performance. As said before the 3800 isn't a motor that sounds good in the first place

charlieRobinson wrote:

why is there so much dis on the 3800's exhaust sound? I think it sounds fine stock and can be greatly improved with exhaust mods. See Abaddon's Riv for a great example.

The 3800 II can for sure be made to sound great. No doubt about it.

  I still need to post the "new" sound.

So I've decided I might do away with my Flowmaster Delta 50's and get something quiter. With my Flowmasters I have more inside noise than I wanted and they are a little louder than I thought they would be outside of the car as well. I'm just not sure what to get to replace it. Def something quiter inside and out.