Exhaust Frustrations...

Today's rant... So I picked up my Roadmaster from my friend's shop yesterday...and it just soulds flat terrible now. To re-cap, I'd decided, since this is NOT a trip/daily car anymore, to remove the resonators and install chrome tips about two weeks ago. I knew the 11-year-old Flowmaster 40's might drone a bit, but wanted to add a little more rumble to my favorite car. Resonators removed and chrome tips added, the car had a little drone at 45-55 but other than that was fine...and sounded mean. WELL that first weekend I took the car to the Dripping Springs Cars and Coffee, and on the way home the 135K-mile passenger-side original catalytic converter started rattling..broken internally. SO I found a set of Magnaflow low-restriction catalytic converters with pipes and 02 bungs. I figured...replace both sides...since the other one, not broken, but has 135K miles on it too...and is most-likely a bit restricted. Well as-noted yesterday the driver's-side converter had the 02 bung in the wrong location, right where the shifter-linkage sits. SO my friend just replaced the passenger-side, and re-installed the original driver's side. I picked the car up last evening, and it sounds like total CRAP! I'm not sure if the one free-flow cat is letting more exhaust through, or if it's having one stock old cat and one new free-flow cat, but the car just drones like crazy now...and I also feel a vibration at idle and just off-idle it's never had before...this car has always been smoooth. When I rev the motor it sounds raspy too..yuck. I'm just pissed...wish I'd just left it ALONE! For 11-years it sounded good with the stock exhaust and the Flowmasters...but I HAD to mess with it. For now, I'm going to see if I can get the bung on the other new cat moved to the right location at my local exhaust shop, and then will install that other new cat and see how it sounds, and then will determine if I want to re-add resonators or replace the Flowmaster 40's with different mufflers. I like a nice rumble...but I don't want my wagon to sound like an old redneck truck.. Grrr....




-Texas Mike

Ditch the Flows, put resonators back on, enjoy.

you know, your tuner will probably edit your tune to remove your rear O2 sensors on your off-road only car *stomp stomp* for free. Pretty sure shipping will be less than moving the bung. Just plug it with a nut.

I enountered a similar issue with my '04 Chrysler Town & Country when I replaced the original catalytic converter with an aftermarket one. The aftermarket cat was a lot louder than the stock one. It's also smaller.

Clearly a lot has changed in emissions technology since older cars were new. If you're questioning your driver's side cat, just look in from the downstream side while you shine a flashlight in the upstream side. If you can see through most of the grid, it's fine.

And yes, what Jayoldschool said, put the resonators back on. They cost you zero horsepower and kill the internal resonant frequencies in the exhaust system that cause drone.

SO just to update, I took that new converter to my exhaust folks, Taylor Muffler here in Taylor Texas. They welded the hole that was in the wrong location, and drilled and welded-on a new bung in the correct spot, and installed the cat.

I then had them cut off the old Flowmater 40's and we discovered the one on the passenger-side was totally clogged with failed catalytic converter packing...nice. I ended up installing new Flowmaster FlowFx straight-through (not chambered) mufflers. That was it for that trip.

The wagon sounds good again and seems much happier to be able to breathe again. I DO think I may re-install some kind of resonators at the very back, as it does have some drone at certain speeds.

Projects!

-Texas Mike.

Glad you got things fixed.  I was going to say you might get the vibration from the loss of the weight thingee that is placed on/near the end hook up area of the pass side cat pipe.  But it looks like you found the issue!

So it turns out when my friend installed the new cat converter w/pipe on the passenger-side of my 96 Roady, he left the damper weight off, because he said the bracket didn't line up correctly.  He said it would have to be drilled to mount it.    

To be honest, I never even KNEW it had this weight on the exhaust until it was mentioned after the fact.    Well I DO have an odd resonance at certain speeds, and I believe I need to have this damper re-mounted.   He has the damper weight at his shop still...thankfully.    I'm not scared to modify the mount to re-mount it, but I don't even know how exactly it fits.   Anyone have a picture?   And I'm curious, why is there only one damper?   Should there not be ones on each side?  It IS on the passenger-side, correct?

Looking forward to hearing replies and hopefully seeing a pic.   THANKS ALL!

-Mike

I've never added mine back...but I don't mind a little drone honestly. I have also seen some get another weight and add it to the other side. From my understanding, it is to help reduce harmonic vibrations that could cause drone on a stock exhaust. Prob on the pass side due to the way an engine will "torque" under load going forward? To the right? So will the right side naturally have more vibration?

Dunno...

Pics I found online:

As always, you're the man brokecello!!!

I always thought the weights were to counterbalance the exhaust system for stress purposes, and allow the replacement of the cat without the catback rotating up, and away from the cat pipe.

If anyone tells you that you don't need the exhaust damper/weight near the catalytic converter on the passenger side...they are wrong. Car had a noticeably rougher idle in gear without it. Added it back and the wagon is smooth as glass again.



Finally took some good pics of the updated exhaust system. Flowmaster FlowFX straight-through mufflers, free-flow Magnaflow catalytic converters, and new straight-through rear resonators with angle-cut chrome tips in the stock locations.




Love the chrome tips too, but I have to get under here with the pressure washer and blow off all that ugly undercoating that's coming off the tank and floorspans, and want to re-paint the bare lower framewells and driveshaft.  I drive that car on the beach down at Corpus ONE TIME and now it looks like that! Crazy!  Dang!



Still the exhaust came out really well!  Nice mellow sound and no drone.




-Texas Mike

Guess, I better put the weight back on to fix the rough idle my wagon doesn't have.

94Woody wrote:

Guess, I better put the weight back on to fix the rough idle my wagon doesn't have.

To be clear it was not really a rough idle...you could just feel a slight vibration through the floor...through the seat and your feet, that went totally away when that weight was re-installed. Really only noticed it when sitting at a light with the car in gear and a/c on, but the before-and-after difference was for-sure noticed by myself and my passenger.

If you have a loud exhaust or a big cam or something...again it might not be missed, but after 11-years I know the "feel" of my old whale-wagon. I'm actually kicking around pulling a weight off the driver's-side exhaust on a Fleetwood during fall junkyard adventures...just to see if adding one to that side makes a difference too.

-Mike

Glad you got it adjusted how you want! System looks really good too. I only knew about the weight because of my cello life...we have to buy little things called "Wolf Eliminators" (which are little weights) to add them to a specific string to help eliminate the wolf tone (or vibration) made when you hit a certain note on the cello.

brokecello wrote:

Glad you got it adjusted how you want!  System looks really good too.  I only knew about the weight because of my cello life...we have to buy little things called "Wolf Eliminators" (which are little weights) to add them to a specific string to help eliminate the wolf tone (or vibration) made when you hit a certain note on the cello.  

Well I'm glad I killed the wolf in my wagon. Ha! Thanks again for the pics!

So mike has to put a cello on his exhaust to get rid of wolves howling?

I'm so confused,.

So how long until you paint your driveshaft? :p


Looking good, Mike.

RedandBlack wrote:

So how long until you paint your driveshaft? :p


Looking good, Mike.

I'm planning to paint the driveshaft and bottoms of the frame rains this fall, along with taking a pressure-washer to the undercoating on the fuel tank that's falling off now.

Yes my OCD flared-up badly when looking under the car on the lift. It did NOT look like that just a few years ago. I drove the car on the beach and bay sand down on North Padre Island and I'm convinced, even though I sprayed the underside off really well right after at a car wash, that I got some salt-water spray under there.

Projects!

That's a bummer.

VHT Epoxy primer in satin black looks really nice and lays down well. I sprayed my entire floor pan and frame with it under the car. Still holding up 4 years later.

Looks like the shop does some clean work for custom sweet!

The most satisfactory modification to my exhaust, was the addition of an Xpipe. Changed the note from pickup truck to sports car instantly. Smoothed out idle and response. It maybe something to consider in the future.

BBK headers> Custom X pipe> Custom 3" pipes> Flowmasters> Rear Exit Chrome Tips.

3600-3800 stall converter lets it sound off nice.

When the rear pop outs are open it sounds a bit evil in the tunnels, makes me grin on the worst days.

RedandBlack wrote:

That's a bummer.

VHT Epoxy primer in satin black looks really nice and lays down well. I sprayed my entire floor pan and frame with it under the car. Still holding up 4 years later.

Thanks for the tip! May try that stuff. It's all just surface rust but it bothers me.

-Michael

gingergarnet1111 wrote:

Looks like the shop does some clean work for custom sweet!

The most satisfactory modification to my exhaust, was the addition of an Xpipe. Changed the note from pickup truck to sports car instantly. Smoothed out idle and response. It maybe something to consider in the future.

BBK headers> Custom X pipe> Custom 3" pipes> Flowmasters> Rear Exit Chrome Tips.

3600-3800 stall converter lets it sound off nice.

When the rear pop outs are open it sounds a bit evil in the tunnels, makes me grin on the worst days.

Two people worked on it, and you can really tell the difference in skill-level between the kid that welded on the mufflers and the owner in his late 50's that did the resonators. The welds on the resonators are beautiful...the muffler welds...not so much...but they don't leak and it sound really nice again now. It's just a low rumble at idle but it barks well when you goose it and sounds great wheel accelerating. Happy with it for now!

Sorry to hear about your frustrations...  I had the driver side cat go bad on my at about 175K and of course just a month or so before emissions was due..  got one thru NAPA and its been fine. I run reg cats, Pypes X pipe Thrush Turbos, and a 2.5 over the axle pipe with Resonator delete. The Thrush's are a bit quieter that i would have liked but still sound nice when you stand on it.

Off topic 81x11, but where are people getting the impala SS style wheels with the Buick centers? I have seen them in a few places around the web and looking for a set.

thanks

gingergarnet1111 wrote:

Off topic 81x11, but where are people getting the impala SS style wheels with the Buick centers? I have seen them in a few places around the web and looking for a set.

thanks

I actually had these made and sold them for a couple of years, but my print shop got wise and tried to raise my pricing on making them, so I stopped.

I need to look around and see if I can find another shop that's not so greedy...

-Mike

You can get these dirt cheap from eBay

https://www.ebay.com/itm/4pcs-65mm-Wheel-center-Hub-Sticker-Cover-Caps-Car-Logo-Emblem-Fit-for-Buick/273381413122?hash=item3fa6cd5102:g:towAAOSw519bYDta

I run them on my daily driver Buick Century with FWD Impala wheels (same exact center cap)

RedandBlack wrote:

You can get these dirt cheap from eBay

https://www.ebay.com/itm/4pcs-65mm-Wheel-center-Hub-Sticker-Cover-Caps-Car-Logo-Emblem-Fit-for-Buick/273381413122?hash=item3fa6cd5102:g:towAAOSw519bYDta

I run them on my daily driver Buick Century with FWD Impala wheels (same exact center cap)

Thanks for posting this..... and ..... the Link....

I blew in there and bought two sets......
You just know you're gonna lose ONE... some day.....

Yep I did the same thing... hahaha

Sorry I hijacked your thread, Mike.

""that I got some salt-water spray under there.""

If you listen carefully at night, you will hear the tiny salt monsters devouring your ride. Ocean salt spray is worse than de-icing corrosion creators. The manufacturers use it to run 10 year wear tests in 90 days.

Rev Bob wrote:

""that I got some salt-water spray under there.""

If you listen carefully at night, you will hear the tiny salt monsters devouring your ride. Ocean salt spray is worse than de-icing corrosion creators. The manufacturers use it to run 10 year wear tests in 90 days.

I believe it! I didn't go blasting through the waves, but did drive on some damp (firmer) sand. I sprayed the underside off the same day, but still it has light surface rust on it now that it never had before.

No pics of the Roady on the sand, but we ALWAYS cruise on the beaches when we go to North Padre Island. It's such fun to cruise on the sand!

ugh... same thing happened to my frame - was west coast florida car all it's life, but after a few times visiting family on east coast (a few blocks off beach) and parked in the driveway, it developed the surface rust on the frame rails

""It's such fun to cruise on the sand!""

Only in a rental car.

Fresh water beach,. Good for the underneath,..

Nice looking exhaust! I've never heard of those weights..lol...the guy I bought my 91 from had a flowmaster on it but took it off and straight- piped it...its a little loud but not bad and idles real smooth.

Phantom 309, that's a nice pic!