straight thru high flow.
Loud Vette
Thread Starter
Intermediate
Joined: Jan 2013
Posts: 40
Likes: 0
From: Riverview Florida
Loud Vette
Hi everyone
I have a 1992 LT1 C4 which I bought used. It has shorty headers, stock mufflers wit no cats from previous owner. I wanted more sound so I installed a set of muffler eliminators and this car may have just became a little too loud. idle is very calm and when coasting at 70 is calm but if I touch that gas BOY she awakes.
I don't mind the outside noise, it sounds good but its a lot to deal with on the inside. i'm looking for answers to calm it down a little. Wondering if I should install cats? I do want to keep my eliminators.
Thanks
BWB
I have a 1992 LT1 C4 which I bought used. It has shorty headers, stock mufflers wit no cats from previous owner. I wanted more sound so I installed a set of muffler eliminators and this car may have just became a little too loud. idle is very calm and when coasting at 70 is calm but if I touch that gas BOY she awakes.
I don't mind the outside noise, it sounds good but its a lot to deal with on the inside. i'm looking for answers to calm it down a little. Wondering if I should install cats? I do want to keep my eliminators.
Thanks
BWB
Advanced
Joined: Jul 2013
Posts: 92
Likes: 2
It will get more quiet if you install cats. Worth trying! I have melrose long tubes, 3" metal cats, stock resonator modified to be muffler and muffler eliminators at back. Quiet enough to drive looong trips without getting annoyed. And no drone!
Burning Brakes
Joined: Jun 2000
Posts: 865
Likes: 6
From: Auburn Michigan
I had stock manifolds, straight duals, no cat with Hooker Aerochamber mufflers on my 85 and it was very loud. Very nice, low frequency sound, but loud. (not like the annoying "crackle" noise of straight piped pee-cup trucks that leave the bar a couple miles down the road at 2:30am)
I was very happy with the sound, but thought I should try to tone it down a little, and try to reduce some of the drone. Last summer I added a couple low cost resonators (glass packs) from Summit and welded them on. They come in all different lengths/sizes, and I bought the shortest ones (12" body I think). It did tone it down, but not quite as much as I thought it would. If I had to do over, I would get resonators with a longer body.
Jones makes many other sizes than what Summit lists, but I they may be able to get the other sizes in. For an inexpensive glass pack, I'd give them a 9/10. I was expecting difficult to weld thin gage metal, but they are very stout.
Melting Slicks
Joined: Jun 2013
Posts: 3,065
Likes: 39
If you put the cats back on you will probably lose some power.
I recommend you find a cheap but good muffler like Flowmaster or Dynomax and sell the eliminators so you don't lose power.
My L98 has Long Tube headers, gutted cat and 2 Dynomax Ultra Flo mufflers, with a flat tappet ZZ409 camshaft that also contributes to sound, but it sounds awesome. Loud, but not too loud.
I recommend you find a cheap but good muffler like Flowmaster or Dynomax and sell the eliminators so you don't lose power.
My L98 has Long Tube headers, gutted cat and 2 Dynomax Ultra Flo mufflers, with a flat tappet ZZ409 camshaft that also contributes to sound, but it sounds awesome. Loud, but not too loud.
Race Director
Joined: Feb 2002
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From: Compound in the Grove, Ga.
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St. Jude Donor '16
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Burning Brakes
Joined: Mar 2005
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Likes: 2
If you put the cats back on you will probably lose some power.
I recommend you find a cheap but good muffler like Flowmaster or Dynomax and sell the eliminators so you don't lose power.
My L98 has Long Tube headers, gutted cat and 2 Dynomax Ultra Flo mufflers, with a flat tappet ZZ409 camshaft that also contributes to sound, but it sounds awesome. Loud, but not too loud.
I recommend you find a cheap but good muffler like Flowmaster or Dynomax and sell the eliminators so you don't lose power.
My L98 has Long Tube headers, gutted cat and 2 Dynomax Ultra Flo mufflers, with a flat tappet ZZ409 camshaft that also contributes to sound, but it sounds awesome. Loud, but not too loud.
I bet you would benefit ditching that single cat exhaust and running a dual exhaust back to your ultra flows.
On my otherwise stock LT1 car I ran muffler elims and loved the sound, I had no resonator on the car and little did I know the cats were empty too. It was just too loud to live with. I would almost bet with some cats it would have been perfect.
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Melting Slicks
Joined: Jun 2013
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Flowmaster mufflers are over rated, more times than not create drone, especially in our cars.
I bet you would benefit ditching that single cat exhaust and running a dual exhaust back to your ultra flows.
On my otherwise stock LT1 car I ran muffler elims and loved the sound, I had no resonator on the car and little did I know the cats were empty too. It was just too loud to live with. I would almost bet with some cats it would have been perfect.
I bet you would benefit ditching that single cat exhaust and running a dual exhaust back to your ultra flows.
On my otherwise stock LT1 car I ran muffler elims and loved the sound, I had no resonator on the car and little did I know the cats were empty too. It was just too loud to live with. I would almost bet with some cats it would have been perfect.
Plus, Dynomax is also a lot of drone, so was my straight pipes. If you don't want drone you gotta go with Corsa. I can deal with the drone.
Race Director
Joined: Feb 2002
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From: Compound in the Grove, Ga.
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St. Jude Donor '16
Still have the stock set up cats/resonator mufflers eliminated on my LT4 sounds great no drone.
Team Owner
Joined: Sep 2003
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From: Freedom is never more than one generation away from extinction.
St. Jude '03 thru '24
Or the ceramic is fine.
Both provide very minimal flow restriction and will "smooth out" the exhaust and dampen it a bit.
This should provide the sound your looking for.
Plus the smell from behind will be much better.
Team Owner
Joined: Dec 1999
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From: Lacey WA RVN 68-69
NCM Sinkhole Donor
If you put the cats back on you will probably lose some power.
I recommend you find a cheap but good muffler like Flowmaster or Dynomax and sell the eliminators so you don't lose power.
My L98 has Long Tube headers, gutted cat and 2 Dynomax Ultra Flo mufflers, with a flat tappet ZZ409 camshaft that also contributes to sound, but it sounds awesome. Loud, but not too loud.
I recommend you find a cheap but good muffler like Flowmaster or Dynomax and sell the eliminators so you don't lose power.
My L98 has Long Tube headers, gutted cat and 2 Dynomax Ultra Flo mufflers, with a flat tappet ZZ409 camshaft that also contributes to sound, but it sounds awesome. Loud, but not too loud.
Flowmasters like the Super 44's or even the 40 Series are probably the worst for interior resonance. Some people have also reported that the Flowmasters will have more backpressure than mufflers like the DynoMax and may cause a slight loss of power.
I use DynoMax race mufflers on my '87 with Hedman longtubes, true duals, and an X-pipe located about 10" past the collectors. There is very little noise and no drone at all at cruising speeds. Even at WOT, I really don't hear a lot of interior noise. But at one area track that uses microphones for checking noise limits, the car has been read at 101 dB (3rd gear, WOT at 5500 RPM).
Burning Brakes
Joined: Mar 2005
Posts: 800
Likes: 2
Factory LT1 cats flow very well and re-installing them may only cost 2-3 HP. The OEM exhaust from the manifolds to the center resonator is 2-3/4" in diameter so there is very good flow. Also with the stock LT1 exhaust, the factory mufflers don't really quiet the exhaust that much. Between the cats and the resonator (which is a fairly long open X-pipe) and the larger pipe diameter, most of the noise has been dampened by the time the exhaust gasses and sound hit the mufflers.
Pro
Joined: Mar 2013
Posts: 628
Likes: 13
From: Indiana
I saw an LT1 resonator cut in half and it consisted of two pipes with holes the entire length wrapped in sound deadening material inside of a single enclosure. So the labeled "Dual Exhaust" on an LT1 is not a true dual exhaust. I guess the resonator could be considered a cross pipe of some sort. It most likely does reduce the noise level considerably.
Burning Brakes
Joined: Mar 2005
Posts: 800
Likes: 2
It does reduce sound, just not as much as you think. That's why a lot of people do muffler elims and leave the res in place. It quiets thing some, but gets rid of resonance, hence the name. The reality of it is, the cats quiet more than the resonator.
Melting Slicks
Joined: Nov 2013
Posts: 2,264
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From: Orchard Park NY