71Riviera questions

[Duff71Riv]

I have a 71 Riviera, 455, and I was wondering what size cherry bomb would sound good? 

Thanks! This is my first car, Iḿ only 15 but I love these old land yachts!! 

[old car fan]

How about a original muffler,it's a 455.Still sounds great.

[Duff71Riv]

It already has an aftermarket glasspacks(not by me) but I does sound good right now. It just is a little too quite high end 

[Duff71Riv]

It already has an aftermarket glasspacks(not by me) but I does sound good right now. It just is a little too quite high end. I’m looking at 2” dia with 12” length would that sound better?

[old car fan]

The original,WITH a 445 ,still sounds great.keep it quite,sleeper.

[Duff71Riv]

Alright, that’s not a bad idea. Thanks old car fan for the quick response!

[Laughing Coyote]

A car with a nice rumble sounds good and still gets attention, but one that is just loud for the sake of being loud is annoying.  JMO.

[rocketraider]

There's PLENTY of rumbly mufflers that sound better than a Cherry Bomb (which is basically just a glasspack painted red)! Look into Walker DynoMax for one; I know a lot of guys using them and very happy with them. I used to like Flowmasters but anymore they have a drone at cruising speed that gets on my nerves after a few miles. You might find that a local muffler shop stocks a good generic turbo style muffler, for less money than name brands, that will sound good.

 

The key to a car like a Riv is subtlety. Dual pipes with a rumble at idle that turns into a snarl under acceleration. Not something "barky" like glasspacks.

[zipdang]

I replaced the remains of the original exhaust on the '71 I owned, and got lots of complements on the sound after installing a factory original exhaust. Even the exhaust guy that bent my pipes was quite surprised. He had tried to sell me something throatier.

[Duff71Riv]

Ok I’ll look into Walker Dynomax thanks. Would u change the 2” exhaust up for a larger diameter or leave it be?

[old car fan]

Depends on your budget,does the complete system in need of replacing.

[Duff71Riv]

No I actually just had the car looked over by a mechanic cuz it was sitting for a LONG time. No exhaust leaks so everything is ok right now. I could afford manifold back if I shoot them out the sides instead of over the rear end

[Paul Dobbin]

It's possible that a car of that size & vintage had a muffler and a resonator to tame the sound.

Maybe a section of pipe to replace the resonator would produce the big Block sound you'll like.

It worked on my 390 T-Bird, but I still vote for silent power in big cars.

My wife had a 1994 Cadillac Fleetwood with a LT-1 Corvette engine.  A really fast car that

surprised a lot of little Hondas with noisy mufflers. (6 que tips, out having fun on Friday

nights)    

[lump]

I'm an old reformed street racer. Had MANY hot rod exhaust systems in my day. But the main reason for the "loud" pipes was trying to gain horsepower. And that started by using headers, with the pipe from the exhaust port of each cylinder down to the collector being the exact same length. If you aren't using headers, then glass packs are nothing but noise. 

 

Headers provide instant power gains, but create endless headaches under your hood, with burnt spark plug wires, recurring leaks, difficult or impossible access to spark plugs and other components, etc. In the end, IF you were racing back in my day, then of course you were willing to put up with the hassles. But no point in racing with a big heavy, wonderful Riviera, when lighter cars with the same engine have too many advantages. So, why put up with the hassles? 

 

My opinion: Save your pennies, nickels, and dimes, and build up enough cash to replace your entire exhaust system with stock components. You could add throatier mufflers, perhaps. Not much difference in cost. Then, if you want to build a hot rod or competitive car, choose a platform that would make that easier, and keep the Riviera for hauling around your beautiful young girlfriend and comfortable cruising. Cars like Chevy Nova 1968-74, Chevelle or Malibu 64-77, or 78-82, Mustangs, 1964 to 1973, Falcons, Darts, Skylarks, and SO MANY MORE cars are still affordable, and easy to make competition cars out of. 

 

That very-classy Riviera will still be cool for generations to come, if you keep in that way. Best wishes to you. Cheers! 

[46 woodie]

I gotta agree with Rocket. There are several companies that build mufflers other than "Cherrybomb". I also think they will be way too loud for your application. After driving a few hours with that noise, it gets really old.

[Frantz]

Don't forget to save the factory manifolds then too! You wouldn't be the first guy to spend a whole lot more money down the road if you decide to go back to stock trying to find factory originals! If you're looking at a street car on somewhat of a budget then I would stick to the factory size. Easier to find headers that way and fewer pipes to engineer. 71 Riviera is one of the best looking cars of the period, congrats and welcome to the hobby!

[Stooge]

a 12" cherrybomb just sounds loud sitting at my desk! I have dual Porter steel packs on my c10, that are about twice that length and although they sound great, they are on the cusp of being questionably loud and I try not to start it up too early if its parked outside. I've used a few different flavors of Dynomax mufflers, and have generally been happy with them, though they have a few race/ turbo style mufflers that are basically just straight through and sound like it, but they have some good budget friendly mufflers that wont make you hate driving, as well as some quiet design ones to mimic a stock style muffler.  Borla has a few offerings that can be tame enough at idle,  have a really nice sound when stepping on it, but they can be fairly expensive. I've never been a fan of the sound of flowmasters and the last few times I've used magnaflows on cars, they have had a lot of cabin drone and get old quickly.

Edited September 18, 2018 by Stooge (see edit history)

[60FlatTop]

14 hours ago, Paul Dobbin said:

I still vote for silent power in big cars.

 

I will pay extra for silent, sometimes a lot extra.

 

One of my cars has 438 factory HP, silent as an electric car, without a hint of exhaust pipe at the rear. Anything else would just be so.... plebeian.

[JACK M]

If you choose to dump you exhaust out the side you will quickly tire if the drone you get.

Better to run a good solid no leak system all the way back with no muffler .

Sounds kick ass in slow traffic and you tend to out run the noise at speed.

[Duff71Riv]

Thanks for all the input everyone! lump, I really like that idea! For a classy car like my Riviera, I now realize that a stock, sleeper would sound better than some punky Honda ricer kinda sound. It saves a few bucks too that i could put in a second project

[Pfeil]

16 hours ago, lump said:

I'm an old reformed street racer. Had MANY hot rod exhaust systems in my day. But the main reason for the "loud" pipes was trying to gain horsepower. And that started by using headers, with the pipe from the exhaust port of each cylinder down to the collector being the exact same length. If you aren't using headers, then glass packs are nothing but noise. 

 

Headers provide instant power gains, but create endless headaches under your hood, with burnt spark plug wires, recurring leaks, difficult or impossible access to spark plugs and other components, etc. In the end, IF you were racing back in my day, then of course you were willing to put up with the hassles. But no point in racing with a big heavy, wonderful Riviera, when lighter cars with the same engine have too many advantages. So, why put up with the hassles? 

 

My opinion: Save your pennies, nickels, and dimes, and build up enough cash to replace your entire exhaust system with stock components. You could add throatier mufflers, perhaps. Not much difference in cost. Then, if you want to build a hot rod or competitive car, choose a platform that would make that easier, and keep the Riviera for hauling around your beautiful young girlfriend and comfortable cruising. Cars like Chevy Nova 1968-74, Chevelle or Malibu 64-77, or 78-82, Mustangs, 1964 to 1973, Falcons, Darts, Skylarks, and SO MANY MORE cars are still affordable, and easy to make competition cars out of. 

 

That very-classy Riviera will still be cool for generations to come, if you keep in that way. Best wishes to you. Cheers! 

Just  not about building a hot rod. Depending on the state where you live and also dealing with Federal mandates. Some of the cars you mention to hot rod cannot legally be hot rodded. Arizona emission test cars all the way back to 1967, and in California 1966-1974 vehicles must have all their emission equipment on the vehicle and working and even though they are not tested. 1966-1974 were tested in the past, but they can be brought back into testing if the Air Quality Management districts deem it necessary to meet air quality goals.  California cars built after 1974 model year with catalytic converters must be tested indefinitely and must have all their emission systems working. So legally 78-82 Mustangs can't be touched, neither can a 76 Malibu or a 1971 Riviera.

 1975 and newer you have Federal laws regarding emissions. Please remember it's not just the testing numbers at idle and 2500rpm, but also your car has to pass the visual first to make sure everything's there first before testing begins.

Before you begin Read your State and Federal  emission standards before you begin.

 

Edited September 18, 2018 by Pfeil (see edit history)

[old car fan]

Sometimes the original cast manifold are better than headers as far I'd size.W30 olds for example.

[Laughing Coyote]

Since I live in the county and don't work in the city limits of Tucson I don't have to emission my newer vehicles. If you commute to work in the city you will have to do emissions.

Edited September 18, 2018 by Laughing Coyote (see edit history)

[lump]

46 minutes ago, Pfeil said:

Just  not about building a hot rod. Depending on the state where you live and also dealing with Federal mandates. Some of the cars you mention to hot rod cannot legally be hot rodded. Arizona emission test cars all the way back to 1967, and in California 1966-1974 vehicles must have all their emission equipment on the vehicle and working and even though they are not tested. 1966-1974 were tested in the past, but they can be brought back into testing if the Air Quality Management districts deem it necessary to meet air quality goals.  California cars built after 1974 model year with catalytic converters must be tested indefinitely and must have all their emission systems working. So legally 78-82 Mustangs can't be touched, neither can a 76 Malibu or a 1971 Riviera.

 1975 and newer you have Federal laws regarding emissions. Please remember it's not just the testing numbers at idle and 2500rpm, but also your car has to pass the visual first to make sure everything's there first before testing begins.

Before you begin Read your State and Federal  emission standards before you begin.

 

Actually, all of the cars you mention can be legally modified, as far as I know, although there may be some exceptions in California. You just have to keep all catalytic converters and other air quality components in place and functional. Today, many header manufacturers make units with fittings for installing A.I.R. fittings and other such components. During my time on the board of directors of SEMA, we were constantly dealing with these issues. And while even now there is PROPOSED legislation which would ban ANY use of any modern car for racing, or modifying them in any way, those laws have been defeated again and again. SEMA has the SAN Network which all car clubs ought to belong to, in order to stay informed, and for collective strength. 

 

But with a 1971 Riviera, I'm pretty confident you can modify that exhaust system even in California...but in CA you'll have to integrate all pollution components with it. 

[Duff71Riv]

It’s a California car but I’m actually in Ohio right now and it’s exempt due to age. I read the manual over and it had no mention of a cat in the “emisions” section so I think it’s alright

[Duff71Riv]

I just registered the car a few weeks ago and everything passed. They didn’t let me get a historical plate though because they said it’s illegal is daily drive a historical plate car in Ohio (I’m not sure why) but I’m sure it’s very losely enforced. 

[TerryB]

15 minutes ago, Duff71Riv said:

I just registered the car a few weeks ago and everything passed. They didn’t let me get a historical plate though because they said it’s illegal is daily drive a historical plate car in Ohio (I’m not sure why) but I’m sure it’s very losely enforced. 

In PA we have the same rule.  For us, the historical car is exempt from our annual safety inspection requirement and some owners may view that as a way to drive an unsafe or car with questionable modifications every day.  

[Pfeil]

In the last two states I've lived in and I'm sure the rest of the states as well the Historic Plates were done for a reason. That reason was that historic vehicles with historic plates are not driven enough to cause any significant impact on emissions. Historic Plates and historic or antique insurance dictates the miles driven. A daily driver exceeds these parameters. According to my local MVD and my antique insurance the moment you change anything on the vehicle ( especially emission controls ) from how it came from the factory your car is no longer historic nor a antique vehicle. What you have is a modified vehicle. Your modified vehicle can still be a collectible car, however it has lost it's historical significance. 

[lump]

34 minutes ago, Pfeil said:

In the last two states I've lived in and I'm sure the rest of the states as well the Historic Plates were done for a reason. That reason was that historic vehicles with historic plates are not driven enough to cause any significant impact on emissions. Historic Plates and historic or antique insurance dictates the miles driven. A daily driver exceeds these parameters. According to my local MVD and my antique insurance the moment you change anything on the vehicle ( especially emission controls ) from how it came from the factory your car is no longer historic nor a antique vehicle. What you have is a modified vehicle. Your modified vehicle can still be a collectible car, however it has lost it's historical significance. 

wow, that's amazing, and totally different than here in Ohio. Indeed, I didn't realize it was really that different elsewhere. Are you certain of this? Which states? 

 

Ohio Historical tags are not to be used for any type of transportation, except to car show events, etc, or to "test and tune."

As you can see, they make no distinction between purely restored or modified antique cars. Below is the info I found on the Ohio BMV website:

Ohio Historical License Plates

You can get an Ohio BMV historical license plate if your vehicle is:

• At least 25 years old.
  AND
• Used only for special events and activities, such as parades.

The historical plate is a one-time fee of $10 PLUS a $21 license tax.

 

[Duff71Riv]

I have a friend who daily drives a 70s MG (if its working) on historical plates and hes never had any trouble. I dont think this law is really enforced but to be safe I just got regular plates. Their more expensive and yearly, but Id rather be safe than sorry. The DMV said if i was caught then they could suspend my license?!

[46 woodie]

If you want to make noise why not install those electric cut outs? Probably a lot less work than changing the entire exhaust. 

[Duff71Riv]

I began looking into those. They are really cool but kinda expensive. Although I guess if you factor cost of a new exhaust it really doesn’t seem that bad 

[Duff71Riv]

[Pfeil]

40 minutes ago, Duff71Riv said:

I began looking into those. They are really cool but kinda expensive. Although I guess if you factor cost of a new exhaust it really doesn’t seem that bad 

I'm sure your neighbors and the neighborhoods you drive through will appreciate that, and giving them a excuse to condemn these old cars. and to impose vehicle inspections in places where they never existed. Also check your MVD/ DMV department rules and regulations. Cut outs are illegal in many/if not all states.

[Pfeil]

While this link applies to cars with a catalytic converter, is also applies to vehicles with exhaust controls which appear in California in 1966 and Federally in 1967.  The law not only applies to you, but if you sell a car with devises disconnected you could be in trouble.

A 1971 Buick has a emission calibrated carburetor, a emission calibrated and controlled distributor also controlled by a TVS switch. The air cleaner inlet air temp is controlled by a ATC valve. Last but not least is your fuel system evaporation is controlled by a carbon canister filter known as a closed fuel system. And believe it or not your rear axle ratio was selected for fuel economy and vehicle emissions results as hard as that may seem to fathom (  I once was able to coax 18-20 mpg out of a 1973 Buick 455  9 passenger Estate Wagon at a steady 55mph with five adults and two teenagers- this is when ca. speed limit was 55MPH at sea level).

 

Please read this link on tampering and keep in mind Ca. is much more stringent and has their own laws which exceed EPA.

Clean Air Act Vehicle and Engine Enforcement Case Resolutions - EPA

https://www.epa.gov/enforcement/clean-air-act-vehicle-and-engine-enforcement-case-

[Duff71Riv]

Wow, 20 mpg out of a 455 is crazy. Exhaust cutouts are illegal, but it seems a lot better than something that's always loud like a glasspack. It keeps everything else stock and it seems easily reversible if I have to change it back. Our town has so many loud cars though I dont think anyone would mind if it was occasional. As for the DMV checks... if they tell me to change it I will (too bad its not a historical plate = one check only) but thats alright. Im just glad to have an old car instead of these 90s blobs in the high school parking lot.  

[Pfeil]

1 hour ago, Duff71Riv said:

Wow, 20 mpg out of a 455 is crazy. Exhaust cutouts are illegal, but it seems a lot better than something that's always loud like a glasspack. It keeps everything else stock and it seems easily reversible if I have to change it back. Our town has so many loud cars though I dont think anyone would mind if it was occasional. As for the DMV checks... if they tell me to change it I will (too bad its not a historical plate = one check only) but thats alright. Im just glad to have an old car instead of these 90s blobs in the high school parking lot.  

The car was my brother-in laws and he could never get past 10MPG. A beautiful wagon painted in Jade Green metallic with Wildcat wheels. He was the only guy I know that on the same car and also a Cutlass of the same year that could burn up a T400, plus wear out nylon timing chain gears in less than 30K. Driving with his foot on the brake most of the time and on the gas and off instead of a steady pedal was his vise and he obviously paid for it with transmissions, timing gears, mileage, and brake pads and shoes.

On a family outing I bet him I could get at least 15MPG out of his Estate Wagon. On the way to the picnic 18 and, on the way home 20MPG of steady 55 MPH mandated FWY driving. Note the EPA figures are 11.1-13.3 MPG, but that is a combined rating and all we were testing was basically a steady state 55 MPH.  The Buick was about a year+ old. That Q jet carburetor is one of the best  for mileage with it's small high velocity primary venturi's, but when the secondary's are open you are getting 800 CFM. And for those of us that do road racing it has a centrally located float so that under high "G" force cornering you will never flood the engine out like what happens to a Holly.

Driving for mileage is, with a properly tuned engine, tires at the very high end of the inflation spec., all in the foot and also keeping your eye on the engine vacuum gauge. The vacuum gauge really is the key and is the next best thing to having a car with a mpg gauge that shows MPG in real time. I have 4 G.M. cars, a 1962, 63, 69 Pontiac's and a 76 Olds and they are all Factory equipped with a vacuum gauge. My two new cars are equipped with a mpg gauge that is always reading in real time.

[Duff71Riv]

The dash on the riviera sadly doesn’t have one, in fact it doesn’t even have an oil pressure gauge or tachometer. I’ll  end up buying at least a tachometer and probably a oil, amp, and temp gauge instead of a temp light. Are vacuum gauges easy to instal?

[Pfeil]

5 hours ago, Duff71Riv said:

The dash on the riviera sadly doesn’t have one, in fact it doesn’t even have an oil pressure gauge or tachometer. I’ll  end up buying at least a tachometer and probably a oil, amp, and temp gauge instead of a temp light. Are vacuum gauges easy to instal?

Vacuum gauges are east to install. T into a vacuum source from the intake manifold and take a wire from the dash light harness for the light in the gauge and then ground the gauge body. Buick did make a Vacuum gauge and a Tach like Pontiac's and Oldsmobile did in the early to mid 60's but they are hard to find, mostly on Wildcats. I couldn't find a Buick gauge on Google however if you Google "Pontiac Vacuum gauge images" a Buick Tach shows up as well as Oldsmobile Tach and Vacuum gauges to give you some ideas of what a Factory gauge looks like.

As far as the replacing the idiot lights go....don't do it. On my cars ( some of them I'm the original owner) I have the Idiot lights and added the gauges, both systems just in case I'm distracted from watching the gauge and something goes wrong I have a light to warn me. 

[lump]

To each his own. Been driving antiques and hot rods for nearly years. NEVER seen any legal problem with modifying cars for more horsepower, greater performance, and with many models you can achieve greater fuel mileage too...if that is what you crave. Manufacturers are forced to make vehicles which please ALL kinds of customers all at the same time, so everything on the car has to be compromised. Not too stiff while cornering for grandma, and yet must provide good handling in the curves, etc, etc. 

 

It's your car...build it to please yourself. My only advice is while a 71 Riviera makes a wonderful, classy cruiser...it's not an easy platform to make a hot rod out of. In MY opinion it's better to "go with the flow," and make the Riviera better at being the kind of car it was designed to be. There are far too many other cars out there which are better choices for hot rodding.