BBC Exhaust Sounds Awful - Will adding glasspacks help?
04-22-2016, 11:30 AM
#1
BBC Exhaust Sounds Awful - Will adding glasspacks help? So I have the original 396 in my 68 Suburban. It's got a mild cam, heads, intake but stock exhaust manifolds. It also has a 2.5 inch true dual (non mandrel) exhaust with 40 series Flowmasters. The previous owner had it installed and looks practically new.
Problem is, it sounds like absolute ****. At idle it sounds good, although a bit too loud given that I want to take my family in it. But once you get going and start revving it up it sounds AWFUL!!!! It makes like blAAAAAAAAt type sound. It's just loud as F and gross sounding, like it is being choked or something.
Headers might help but are down the road for now, but would probably make it louder. So my question is, what will happen if I stick a short glasspack on each side before (or after??) the muffler to use like a resonator? Would it quiet it down some? Change the tone? Better or worse?
This thing doesn't sound like a typical Flowmaster exhaust, maybe the non-mandrel 18 foot long system is causing it? Thoughts on all of this?
Problem is, it sounds like absolute ****. At idle it sounds good, although a bit too loud given that I want to take my family in it. But once you get going and start revving it up it sounds AWFUL!!!! It makes like blAAAAAAAAt type sound. It's just loud as F and gross sounding, like it is being choked or something.
Headers might help but are down the road for now, but would probably make it louder. So my question is, what will happen if I stick a short glasspack on each side before (or after??) the muffler to use like a resonator? Would it quiet it down some? Change the tone? Better or worse?
This thing doesn't sound like a typical Flowmaster exhaust, maybe the non-mandrel 18 foot long system is causing it? Thoughts on all of this?
Last edited by AnotherWs6; 04-22-2016 at 12:30 PM.
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04-28-2016, 09:57 PM
#10
Definitely agree the H pipe will "clean" up the sound a bit. You may want to look at Dynomax ultra flow welded mufflers instead of the 40 series flowmasters. They are roughly the same size and shape, but considerably quieter.
IMO the flowmasters sound good on a race motor, not so much for mild street engines.
IMO the flowmasters sound good on a race motor, not so much for mild street engines.
04-30-2016, 02:45 PM
#11
I second Z28 - H pipe will clean up the sound, an X will as well but won't tame it as much as an H.
Also get rid of the cheap Flowmasters - you get what you pay for. Put a proper brand name set of mufflers on with an X or H and see if you like it when cruising. Can always add in-line resonators from there if it's still too loud.
Long tubes won't help - factory manifolds will be quieter than LTs.
Also get rid of the cheap Flowmasters - you get what you pay for. Put a proper brand name set of mufflers on with an X or H and see if you like it when cruising. Can always add in-line resonators from there if it's still too loud.
Long tubes won't help - factory manifolds will be quieter than LTs.
05-01-2016, 09:29 PM
#13
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Add a couple Vibrant Ultra Quiet resonators. My Nissan Titan was obnoxious after I deleted the cats. I put 2 Ultra Quiets on and it killed the shitty sound and kept a deep tone, but is still loud enough.
05-02-2016, 08:14 AM
#14
Thanks, I am thinking about them, I actually have them in my Amazon cart already. Someone recommended them to me as well and I see many reviews on Amazon and Summit that mimic yours. I'm going to do an H-pipe for sure, but I'm still contemplating whether I should just do the H and see what happens or do the H and the resonators at them same time. Leaning towards the latter - this is meant to be a family vehicle as well as a hot rod-ish type thing. So even if it ended up being a little too quiet for my tastes that would probably be a good thing when on a five hour drive with m wife and daughter.
05-07-2016, 11:24 AM
#15
Launching!
flowmasters on real long systems sound like crap been there with my Camino
Got some ultraflows on there now still kinda loud but sounds great. They make an oval type that is quieter
For something likeyours always liked the long case dynomax turbos, quieter and not as brappy. Glasspacks will sound like a tractor
Got some ultraflows on there now still kinda loud but sounds great. They make an oval type that is quieter
For something likeyours always liked the long case dynomax turbos, quieter and not as brappy. Glasspacks will sound like a tractor
05-07-2016, 06:58 PM
#16
take some measurements of how much space you have. Then locate one or two high quality OEM mufflers from high power cars (same power level as you) and have a good welder/fabricator if you cant handle the job set them up under there.
This will give you OEM noise levels, or nearly so. Then, you can add an electric cut-out to hear the engine when you feel like it. The OEM mufflers will complement the OEM exhaust manifolds, the stock-ish cam, a low stall converter, numerically low gearing, its good for trucks/towing, everything is mated together. What you don't want is a huge old dual 3" exhaust with open dumps. There will not be enough exhaust gas velocity to give you the torque the engine is capable of producing at lower rpms.
This will give you OEM noise levels, or nearly so. Then, you can add an electric cut-out to hear the engine when you feel like it. The OEM mufflers will complement the OEM exhaust manifolds, the stock-ish cam, a low stall converter, numerically low gearing, its good for trucks/towing, everything is mated together. What you don't want is a huge old dual 3" exhaust with open dumps. There will not be enough exhaust gas velocity to give you the torque the engine is capable of producing at lower rpms.
05-09-2016, 05:10 AM
#17
flowmasters on real long systems sound like crap been there with my Camino
Got some ultraflows on there now still kinda loud but sounds great. They make an oval type that is quieter
For something likeyours always liked the long case dynomax turbos, quieter and not as brappy. Glasspacks will sound like a tractor
Got some ultraflows on there now still kinda loud but sounds great. They make an oval type that is quieter
For something likeyours always liked the long case dynomax turbos, quieter and not as brappy. Glasspacks will sound like a tractor
07-18-2016, 12:26 PM
#18
OK - reporting back. I bought a bolt on h-pipe kit from summit, a bunch of their 2.5 inch band clamps and a pair of Vibrant resonators. The raspy sound is now 100% gone. The truck still sounds good, quieter but far from quiet. It has less of the trademark Flowmaster sound - that chamber type sound - but it's got a good, fairly deep rumble. I contemplated just running the H-pipe to see how much that helped, but since this is a family vehicle I threw the resonators on too to make it reasonable to ride in.
Keep in mind that the rear floor of this thing is nothing more than a piece of wood. No carpet, no insulation - just the wood as it came from the factory 50 years ago. It does very little to muffle sound. And with the wheel wells being uncovered as well a good pebble hitting them can make you jump! Sounds like it's next to your head. So it's probably still louder than what would be ideal, but unless I put some suuuper quiet mufflers on I think that it is what it is. All in all I am pleased. I took my wife and daughter to a lake last weekend. Daughter snoozed most of the way there and back, wife was OK with the sound. It was beyond loud over 1,500 rpm before.
Thanks to ringmaster72.
I was looking for a super cheap solution, but we all know how that usually goes. Oh well. I spent around $200 and was able to do it all by myself in my driveway, so not bad.
Keep in mind that the rear floor of this thing is nothing more than a piece of wood. No carpet, no insulation - just the wood as it came from the factory 50 years ago. It does very little to muffle sound. And with the wheel wells being uncovered as well a good pebble hitting them can make you jump! Sounds like it's next to your head. So it's probably still louder than what would be ideal, but unless I put some suuuper quiet mufflers on I think that it is what it is. All in all I am pleased. I took my wife and daughter to a lake last weekend. Daughter snoozed most of the way there and back, wife was OK with the sound. It was beyond loud over 1,500 rpm before.
Thanks to ringmaster72.
I was looking for a super cheap solution, but we all know how that usually goes. Oh well. I spent around $200 and was able to do it all by myself in my driveway, so not bad.