exhaust dilemma

[RivVrgn]

Hey guys, i've seen this subject discussed but I have a differant angle. I'm about to put a new exhaust on my 65. It has the original on it now, plus about five pounds of muffler putty and exhaust bandage. I'm looking at a tranverse mounted flowmaster with no resonaters ( they are shot).

I don't want any popping or cackling like you get from glasspacks (no offense for those who have them). I'm after a mellow rumble sound.

The guy I'm having do it wants to put 2.5 inch all the way, he says that will give a deeper rumble. I was looking at 2.25, since I have a 425 (non GS) and that's what a GS runs, it has the 2 inch on it now. I was wondering should I stay with 2 inch, upgrade two 2.25 or go all out to 2.5. I figure since a GS runs 2.25 with a 425 that would be the way to go. But, is he right will I get a deeper rumble from a 2.5? Also will a 2.5 hurt my performance, because I know you have to have a certain amount of back pressure?

So, everybody put your thinking caps on and let me know what you think.

thanks

Joey #12735

[RivNut]

Joey,

IMHO, 2.5" is just a way for the installer to put some addtional $$$ in his pocket. I've always had this point of contention with larger pipes, even the factory pipes that were on the GS models:

The exhaust manifolds are no different on the GS with it's 2.25 inch pipes and the non-GS models with their 2" pipes. The opening on the manifold is the same size for both sized pipes. Both sized pipes have the same bottle neck before any exhaust gasses hit the exhaust pipes/muffler/tailpipes. Along with the larger 2.25" pipes, does the GS also have larger inlets than the standard exhaust? The standard tail pipes are 1-7/8", does the GS have a larger tail pipe as well as exhaust pipes?

If I were you, I'd have the installer make a full set of 2-1/4" pipes all the way to the muffler, make sure the muffler has 2-1/4" inlet and outlet and use 2-1/4" pipes for the tail pipes as well. The other thing I'd do, and this would involve removing the exhaust manifolds, would be to enlarge the opening of the manifold where it empties into the exhaust pipe.

Flowmaster makes different muffler series. I think you can even go online and listen to the different series to see what you might like in the way of "mellowness." This type of muffler does not have the crackle that you described as found in a glass-pack.

Here's link to a video / audio of five different flowmasters on a '72 El Camino.

Flowmastertv : Featured Flowmastertv // on the PowerTV Network Hope this helps.

Ed

[Jolly_John]

Hello, Joey. I sent you a PM about some stock Riv. exhaust parts I have available. John

[1965rivgs]

In addition to the larger pipes the GS models also followed a different routing. No snaking back and forth under the floor but hugging the frame all the way to the rear, a much straighter path. Tails were also larger than standard at 2 inches, not as large as the header pipes because the muffler and resonators present the most significant "choke" in the system and the they are both ahead of the tails. Choke points are critical but so is system capacity; if the overall system is too small the entire system becomes a choke immediately after the exhaust valve.

I agree with Ed, anything larger than 2.25 on a standard Riv is overkill. In addition, anything larger is even more of a P.I.A. to install properly. The stock style system is hard to get "right", good luck!

Tom Mooney

[CTX-SLPR]

I had good luck starting with TA's 2.5in kit and customizing it to make it fit tighter and I relocated the mufflers to just behind the rear axle with only ~5in of tail pipe afterwards but it gave me more ground clearance and a better sound than the stock system. However I had to get TA to specially make the headpipes since they listed it as working with stock manifolds but that choke point that Ed mentioned in the manifold flanges was wrong so they fixed mine and pulled the fact that it worked with stock manifolds from the catelog.

I now have a single 3in pipe to an F-body 3in in dual 2.5in out transverse muffler and a glasspack type muffler in the middle as a resonator. Oh and I'll have a turbo soon which is like 1/3-1/2 a muffler.

[RivVrgn]

Good points, I think I'm going to go with 2.25, no resonators, and the flowmaster transverse muffler. I might also go with 2 inch after the muffler. If it's too loud I have a line on some resonators.

By the way, what is the reason the exhaust is snaked like it is? Does anyone know?

Thanks all, Joey #12735

[1965rivgs]

To dampen resonance..

Tom

[NTX5467]

Ed makes some very good points! 2.5" pipe might not be capable of being bent without being "squished" in the tighter radius which the stock pipes make with no issues. 2.25" would probably be the best compromise. Pipe thickness, or "gauge" can also affect the ultimate sound of the system, too!

The OTHER thing about getting a muffler-shop-built system is that should it ever need repair, you'll have to find somebody to do what the original shop did, OR one that has those same capabilities. This might not be a really big deal, but it could be in a few years. One reason I prefer OEM-replacement systems or something from an exhaust system supplier, in the larger pipe size, if possible. Not to forget about exhaust system hangers which are at least of OEM quality and configuration! Also, I like clamped systems so that it only takes a wrench and penetrating oil, rather than a "gas wrench", to replace the muffler(s) later on.

I know that FlowMaster is a highly buzz-worthy brand, but I think that if you're more after a "rumble/burble", but without a "drone", you might also consider Walker's DynoMax mufflers. Many are stock OEM replacements, but with better flow. I've listened to the online "sounds" and have found them all flaky. Reason is that each system and engine has their own unique sound, although the FlowMasters have their own signature sound. How many FlowMastered Mustang 5.0Ls have I heard over the years???

Several years ago, I had two friends who were getting their cars ready for a Muscle Car Club shootout drag racing event. One had a '70 Dart 340 with Flowmasters on it, with a slightly hotter cam than stock. The other was a '70 Road Runner 440+6 with the Walkers on it. BOTH cars were very loud inside from exhaust noise. For grins, they both swapped mufflers and both cars got quieter and much more liveable. So, it might be advisable to find a similar Buick engine and listen to the exhaust, then attempt to emulate that sound, if you like it. You might well discover that some un-exotic "replacement" muffler might have the sound you're after.

One function of the smaller hole in the end of the exhaust manifolds, compared to pipe diameter, could also effectively be an anti-reversionary situation. Certainly, it might "neck down" the size and be a "choke", but it can also lessen any reverse pulses in the system.

Both pipe size and how it's bent can affect any system resonances. Longer runs will have lower frequency resonances, for example. The additional bends can also make the pipe stiffer, in comparison. PLUS where the hanger clamps are located can also be a factor.

In shopping for muffler shops, do your due dilligence in making sure what you're getting is what you really want . . . and are paying for. EACH muffler shop has their own "tricks" to do things, by observation, plus ways of doing things . . . with possibly significant differences in price, too. Remember, too, the more involved the pipe bending might be, which relates to "time", the more things can cost. Some people have widely varying views of what a good exhaust system is, too. You might see a system that somebody has raved about and discover it's really hacked together . . . or you might see a system somebody says is "so-so" and it's a really nicely-done system, at a reasonable price. Be that as it may . . .

Sounds like you're got your basic ideas pretty well lined-out.

Enjoy!

NTX5467

[RivVrgn]

In addition to the larger pipes the GS models also followed a different routing. No snaking back and forth under the floor but hugging the frame all the way to the rear, a much straighter path. Tails were also larger than standard at 2 inches, not as large as the header pipes because the muffler and resonators present the most significant "choke" in the system and the they are both ahead of the tails. Choke points are critical but so is system capacity; if the overall system is too small the entire system becomes a choke immediately after the exhaust valve.

I agree with Ed, anything larger than 2.25 on a standard Riv is overkill. In addition, anything larger is even more of a P.I.A. to install properly. The stock style system is hard to get "right", good luck!

Tom Mooney

Even though my cars not a GS, it is 425 equipped. So should I follow the GS routing and follow the frame to the axle. If the bends are to dampen resonance why does the GS not do it? also I guess the 2.25 pipe would be easier to bend following the frame than snaking.

[NTX5467]

The resonance issue is a highly variable one. With the standard system, "silence" was probably a key consideration in how the system was designed and configured. With the more performance-oriented issue of the 425 in place of a 401, there might be an expectation for a little more "sounds" than for the stock 401 vehicle.

The "fewer bends" might have been due to the fact that the 425 system has difference resonances to deal with than the 401 system would. "Fewer bends" also means "less total pipe length needed" to do the complete system, which relates to "$$$$" with respect to "assembly cost" of the vehicle. "Fewer bends" might also give it a more "straight-through" look, which is a visual perception of "higher performance", too. Several possible things . . . visual, financial, and engineering . . . which might have influenced what's under the 425 car.

How closely your system might follow the system for a 425 V-8 Riv can relate to many things AND who you get to do it. Many muffler shops, in running pipes on a vehicle, will generally do it as close to a straight line as they can get away with. This definitely gives the result a "low $$$ look", all things considered. Finding one which will allow your "guidance" and input as it's done, compared to known accurate systems' illustrations, might take some doing, but WHEN you find that shop, you could well get a better-built system AND one that not only looks more correct, but also one which will give fewer problems in the coming years. Unfortunately, these are NOT hard and fast rules. So, you'll need to be there when it all happens. Key things would be how things fit "over the axle/rear suspension area", which can have tight clearances, even for a stock system.

Good luck!

NTX5467

[RivNut]

Sounds logical but all '64 Rivieras came with 425's. Did every 1964 Riv then come with the larger exhaust? The Super Wildcat engine was an option in '64, same as the GS engine. What about the 2,000+ 1965 Rivieras that came with a single 4bbl 425? Did they also come with the larger exhaust? As far as what's been published, only the '65 Gran Sport had the larger pipes. Probably nothing to do with engine displacement.

Ed

[RivVrgn]

My 65 has the 425 single 4bbl (non GS) and it has 2 inch exhaust with all of the bends in it. I'm pretty sure it's original.

The shop I am going to have do it said he will make it just like OE, with all of the bends or how ever I want it. He has done a lot of classics and rods, and stuff in between. He listens to what you want, tells you how he will do it, and you can also bounce ideas off each other. Thats why i've asked the Riv community about my options.

I'm right there with you RivNut, does the 64 have all the bends and or the larger size?

Less bends less money, yes. That might not be a bad idea. If I don't need the bends I don't want to pay for them.But, I guess it will make it a little louder(no resonators and a transverse flowmaster).

lot of info,thanks

Joey #12735

[Guest carlbraun]

Guys

after a lot of head scratching I've decided to go pure stock with my exhaust for my 65 Riv GS. I bought mine from Waldron's in Michigan for $580 +$110 for shipping to so Cal.

here it is...

[TexRiv_63]

A few years ago I had a system done for my 63 Riv 401 at a well regarded custom exhaust shop. It was 2.25" front to back and used a transverse muffler from a later Grand National with no resonators and chrome tips. The pipes were mandrel bent and generally matched the curves and bends of the OE system, some of which are necessary to get the pipes to hug the floor and not be hanging too low. The end product was a work of art and sounded great when I first started it up. When I actually drove it though, I had two problems. The first was a slight buzzing vibration at certain speeds, this was caused by the hangers being set up too tight. The second and worst problem was a sharp rapping noise under acceleration which actually sounded like an engine knock. It actually was the resonance issue mentioned above, in order to solve it two small bullet resonators were added on each side. After that no more rap and great sound. The shop took care of all this at no extra cost. Moral, anything custom will probabaly need tweaking, use a shop you can trust.

[RivVrgn]

Guys

after a lot of head scratching I've decided to go pure stock with my exhaust for my 65 Riv GS. I bought mine from Waldron's in Michigan for $580 +$110 for shipping to so Cal.

here it is...

So, Your GS has all the bends of a regular rivs exhaust? Is it 2.25 inch? Just exhaust no hangers? bolts together?

Joey #12735

[60FlatTop]

Recent experience has given me costly knowledge. Do not buy any "bent" exhaust systems from vendors, including the one above.

If possible buy original equipment "manufactured" exhaust parts like Walker.

If you have to have pipes fabricated only do it in a shop where your car is directly fitted.

Do not buy a muffler from these guys who make replacements in their shops.

Bernie

[Jolly_John]

Hi, Bernie. I hope the original equipment Walker intermediate pipes you bought from me arrived in good shape.

In case anyone is looking, I have one NOS 1963-65 Riviera left intermediate pipe left (the weird, complex pipe between the resonator and the transverse muffler). I also have a pair of correct older, new-in-box resonators remaining. Totally original with factory flaring at one end, and the stock bolt-on flange at the other. John

[60FlatTop]

John,

Thank you. The pipes I bought from you are excellent. No one can match manufactured pipes by using a reference card and a bender. I am stocking up spares every chance I get.

Bernie

[Guest carlbraun]

So, Your GS has all the bends of a regular rivs exhaust? Is it 2.25 inch? Just exhaust no hangers? bolts together?

Joey #12735

Waldron wanted to know (specifically) if I needed my exhaust for a Riv GS vs a standard Riv...they are manufactured differently and require different sized tubing.

I'll have my system installed at a local custom exhaust shop that will use OEM hangars and clamps and, all told, the system will probably total out at $1000. I like the look of stock pipes and resonators as compared to the generic kits offered by the larger vendors.

In my opinion, the GS cars (especially) are getting too valuable to hang a non-stock appearing performance exhaust system on even if it costs a few HP. I had a performance exhaust system (2 1/2" with X crossover) installed on my Ram Air IV GTO after removing a fairly stock exhaust system (2 1/4"). THe flowmaster mufflers sounded pretty cool though there was NO seat of the pants improvement in performance. I did, however, get points deducted at the GTOAA meet in St Louis for non-stock exhaust.

We'll see how it sounds when its installed. I'll take some photos with the car on the rack during installation.

Carl

[George Buick Riviera]

I'll take some photos with the car on the rack during installation.Carl

Carl, please post the pictures and some final informations regarding quality of Waldron product. Was it fitting perfectly, or required some modifications ? etc.

Thank you - this will help me in my future restoration....

[Guest carlbraun]

Carl, please post the pictures and some final informations regarding quality of Waldron product. Was it fitting perfectly, or required some modifications ? etc.

Thank you - this will help me in my future restoration....

Will do.

I'm hoping to receive the exhaust via the shipper within the next few days.

[TexRiv_63]

Joey,

Here is the photo of the resonator you asked for. By the way, I said my system was mandrel bent but looking at these photos I was wrong.

[Guest carlbraun]

In addition to the larger pipes the GS models also followed a different routing. No snaking back and forth under the floor but hugging the frame all the way to the rear, a much straighter path. Tails were also larger than standard at 2 inches, not as large as the header pipes because the muffler and resonators present the most significant "choke" in the system and the they are both ahead of the tails. Choke points are critical but so is system capacity; if the overall system is too small the entire system becomes a choke immediately after the exhaust valve.

I agree with Ed, anything larger than 2.25 on a standard Riv is overkill. In addition, anything larger is even more of a P.I.A. to install properly. The stock style system is hard to get "right", good luck!

Tom Mooney

Tom

Do you have a GM drawing showing the GS exhaust routing? The 65 technical manual shows a single diagram for the 49000 model (Riviera)...nothing special for the GS.

Thanks

Carl

[john hanson]

If anybody is still looking for 63 to 65 rev exhaust i have two sets of pipes no mufflers. These are O.E.M.

John Hanson

johnanddee1956@yahoo.com

[George Buick Riviera]

If anybody is still looking for 63 to 65 rev exhaust i have two sets of pipes no mufflers. These are O.E.M.

John Hanson

johnanddee1956@yahoo.com

Hi John

are these for GS or non GS ?

[whitewatersky]

well, timings everything ! I looked under my baby this afternoon and my muffler's a bit of a dud.

our mechanic who was looking over it was puzzled about the snaking of the pipes here there and everywhere. he'll be interested to read this thread.

i hadn't yet read this thread, but as we were looking it over, he talked about just running pipes straight thru (maybe pop em out in front of the rear wheels, old hotrod style ! or maybe not.....)

we're gonna get the best local exhaust shop to look over it. it'll pass a registration inspection for now, but it needs work.

[RivNut]

I'm betting that the GS pipes follow the same routing as the non-GS pipes. The pipes are larger and have smoother bends, but Buick probably used hangers in the same locations as the non-GS cars. If they weren't routed the same way, a completely different placement of hanger brackets would have to have been made for the GS. I doubt that that would have happened. I'd venture to say that a mandrel bent 2-1/4" set of pipes would give the same flow characteristics as the GS pipes. Remember, the GS package was an option. Most options are designed to be bolted on. The GS is not a separate model.

Ed

[RivVrgn]

After all of the info batted around on here I decided to run 2.25 inch pipe. I didn't follow the original routing though. My exhaust guy came down from the manifolds over the frame, tucked next to the center then turned where the resonators were(i didn't run any) hooked up with the resonator hanger there, (stock hanger placement)went over the axle into the flowmaster muffler (stock hanger placement ) and out the back(stock hanger placement) with factory cuts on the tips (no chrome).

It does have a slight drone in the cabin when it's in gear and you are at a light, but I think I can tweak this with some small resonators. Otherwise it sounds great. I expected to do some kind of tweaking with not going stock.

The exhaust guy did a great job. The pipes are straight as an arrow and the bends on both sides match all the way back. Anybody that can make stuff like this with there hands has my respect any day.

I'll try to get a pic or two. I'm real happy with it.

Thanks for all of the input guys.

Joey #12735

[RivNut]

Joey,

You might be able to get rid of the drone by putting an H or X pipe between the two main pipes. (If it wasn't done that way to begin with.) Any chance of seeing a picture of how the pipes went over the frame instead of under it?

Thanks,

Ed

[60FlatTop]

I wanted to give my Riviera a little rumble last time I needed a muffler. I took a stock muffler and tail pipes as well as a pair of Hushpower mufflers to the shop. I told the mechanic to install the Hushpowers at the rear with an equalizer pipe in place of the original muffler. If it looked like a PIA, just put the stock stuff on.

I brought the stock parts home.

The full size equalizer pipe mellowed it out real nice. It has that bubbly Chris Craft boat sound at idle and a rumble but no drone while driving.

Since these pictures were taken I added short rounded opening chrome tips. Very Happy!

[RivVrgn]

Joey,

You might be able to get rid of the drone by putting an H or X pipe between the two main pipes. (If it wasn't done that way to begin with.) Any chance of seeing a picture of how the pipes went over the frame instead of under it?

Thanks,

Ed

My mistake Ed, I meant under the frame. When you lose your point of reference you don't know what's up or down.

Where would you put an H or X pipe, my pipes follow the frame?

I've got a line on some 12 inch hushpowers that i'm going to put where the stock resonators were. I'll let you know what happens.

Joey#12735

[RivNut]

Most of the systems I've seen have the H / X pipe close to where headers flanges would be if you were running full length headers. However, after having seen the configuration in the picture of 60Flattop's pipes, who's to say that it wouldn't work there. It seems to work for him. He gets the sound he wants without the resonance in the passenger's compartment.

Ed

[john hanson]

I have 1# 1372928 Resonator for 1965 riv. gs only. No other exhaust parts.

John Hanson

[RivVrgn]

Here's what I went with. Pictures aren't real good, the sun was awful bright that day. 2.25 inch to two flowmaster hushpower resonators (mufflers), a flowmaster crossflow muffler and 2.50 inch tailpipes. Pipes run along the frame and the tailpipes have a little turndown with a slight cut in the end. Sounds great, nice and mellow,and the tailpipes look good from the rear with the cut, not just a pipe sticking out.

Joey #12735

[Guest Rob J]

Carl, any updates on pics and fit/finish quality of that Waldron's Exhaust system? I need a new exhaust in the near future, so I would like to hear your feedback.

Rob.

[60FlatTop]

I finally got around to making the tips of mine pretty.

Bernie

[Guest carlbraun]

Carl, any updates on pics and fit/finish quality of that Waldron's Exhaust system? I need a new exhaust in the near future, so I would like to hear your feedback.

Rob.

Rob

the exhaust system hasnt been installed yet. I'm restoring the whole undercarriage of the car and the last thing to do will be the exhaust.

Regarding the waldron's exhaust, the pipes are so beautiful that I dont even want to install them. Pics to follow

[60FlatTop]

Carl,

I am curious about how those new pipes fit. Are they installed?

Bernie

[Guest Gearheadjohn]

In shopping for muffler shops, do your due dilligence in making sure what you're getting is what you really want . . . and are paying for. EACH muffler shop has their own "tricks" to do things, by observation, plus ways of doing things . . . with possibly significant differences in price, too. Remember, too, the more involved the pipe bending might be, which relates to "time", the more things can cost. Some people have widely varying views of what a good exhaust system is, too. You might see a system that somebody has raved about and discover it's really hacked together . . . or you might see a system somebody says is "so-so" and it's a really nicely-done system, at a reasonable price. Be that as it may . . .

NTX5467

Exactly what this man said, I had a shop do the exhaust on my Trans Am and I could have made a better system in my driveway with a box full of 180 degree bends and some straight pipe. I still have it in my garage ill get a pic of it tonight or tomorrow and post it here.

[whitewatersky]

my exhaust from Waldrons has hit Aussie shores.

I'll let everyone know what it's like once it arrives at my place and is fitted.

i didn't get new pipes