I have a magnaflow catback on my 89. It sounds great but has a lot of drone. I have added about 20 lbs of sound deadner and still hasn't helped much.

I think I going to take out the Catalytic converter and replace it with either a straight through resonator or a glass pack. Which would do better at reducing the drone?

Note I am keeping the Magnaflows, so this will be an additional muffler, not the only muffler.

 

You can make all the mid exhaust swaps you want but your drone is caused by the Magnaflows. The drone is caused by mufflers that are designed to absorb sound while mufflers that have no drone are designed to have pressure wave cancelation. Magnaflows are sound absorption design.

If you are 100% committed to keeping the Magna flows, go with the mid section resonator. You will notice a small improvement, but your mufflers will still drone.

 

I bought MAM Quad Power Mufflers for $300. Sound great and no drone. I'm glad I didn't waste my money on the name brands because it seems like they all drone except maybe Corsa if I remember what I've read correctly.

 

Are those "mufflers" actual "mufflers" (with chambers) or more of the straight through design? I looked for them and I came up with a straight pipe design.

 

@billschroeder5842 They're a straight through design but they don't drone. I have them on with a Melrose Smoothflow exhaust system and they don't drone. I don't remember them droning either when I had them on my stock exhaust. All I remember is how good they sound, but I do prefer the more old-school rumble. There's a Melrose thread by 84 4+3 on the forum right now where he has a video of his you can listen to. Any sound clips on my channel would be post header install.

 

You get what you pay for. Sorry, but what did you expect out of Magnaflows?

Almost all cars with mufflers behind the axle suffer from drone with cheaper aftermarket systems. Adding much else to the front won't do much. It is based on frequency and adding another muffler won't change the sound pulse rates. It can obviously reduce it by reducing the sound, but by removing the Cat, you are opening up the exhaust to be louder. If you are set on keeping the magnaflows, you should read this thread.

 

Thanks for the advice. I did not buy the magnaflows, they were on the car when I got it.

 

they're loud and aggressive. I used to take off hard from a light by my house and my buddy used to tell me he heard me grab 3rd. By that point I was well over half a mile away. I love them, but they're not for everyone.

I went under a large overpass in mine at wide open and rolled up to a light last year, a guy in a 69 pulled up next to me, he was behind me and I didn't even notice it, and yelled over to tell me that the thing sounded amazing. I've gotten nothing but compliments on it. To me it reminds me of a 5.0 fox body at wide open that's really pissed.

 

IMO and experience, the "best value" in an exhaust system is, to use a set of long tube headers, and install a stock LT1 exhaust. You have to make or have an exhaust shop make adapters from the headers to the 2.75 exhaust.

FWIW I have been using this setup for a few years now. My car makes 462 rwhp, although, I have not dynoed both systems, I have ran it at the track. I cant see any difference in aftermarket and stock in time slips.

My headers, years ago were $600.00 and a stock exhaust can be found cheap. 100-200 dollars.

I refuse to spend in excess of $2,000.00 for an exhaust on a C4

 

I am not a fan of headers. I've had them before, they are a lot more difficult to get on and off, I don't particularly like the way they sound and mine always seem to leak, either at the head or the collector or both..

 

Seems you have no issue spending it elsewhere.

Money is not only spent for HP/TQ. Ease of installation and appearance are also important as well as materials that protect that appearance. Unless "Race Car" and appearance means zero. I just find it odd that you seem to have no problem spending enough money to get to 460hp to the rear wheels "on a C4" but somehow the exhaust seems to bother you.

 

This is what I plan on doing with my LE2 build. LT headers into a stock system. The only change to the exhaust is a corsa pipe(straight tubes) that replaces the resonator and going with High flow cats.
Back when I joined the forum a few people mentioned LTs to a stock system is No or less drone. Is that the case with your system ragtop 93?

 

Quote:

Originally Posted by auburn2

I am not a fan of headers. I've had them before, they are a lot more difficult to get on and off, I don't particularly like the way they sound and mine always seem to leak, either at the head or the collector or both..

Understood, headers are not for everybody...... If drone is your main concern, I would do the following.
1. Contact magnaflow and see what they have to say. They advertise the system as having a mild interior sound.....
2. Have you considered plugging one of the 2 tips on each muffler. In the past, there has been several post with people doing this on performance mufflers to eliminate the drone.
3. Since you purchased the car with the magnaflow on it, I wonder if by chance someone gutted the cat. that is on the car? You could take it loose on the downstream side and look in there to see. If so, that may be part of your problem.
4. Again, this may not be for you, but since you said you want to keep the magnaflow, and dont mind getting rid of the cat, maybe consider getting an exhaust shop to make a set of true dual pipes coming from the exhaust manifolds to just before the rear axle, and then adding a magnaflow dual inlet and outlet muffler in the system..... Something like the magnaflow 11386.... In addition, it has a built in X pipe. which may help... If you look at the magnaflow system on a 92-96 it would be very similar to that.

Good luck, and let us know what you do.

 

Quote:

Originally Posted by vette196

This is what I plan on doing with my LE2 build. LT headers into a stock system. The only change to the exhaust is a corsa pipe(straight tubes) that replaces the resonator and going with High flow cats.
Back when I joined the forum a few people mentioned LTs to a stock system is No or less drone. Is that the case with your system ragtop 93?

Look forward to heari how that works for you!! First, when I did mine, I had a hotcam, ported heads, and long tube headers. The headers were exotic muscle and used a 3in slip connector. At first, I used exotic muscle header adapters, back to the stock exhaust, no cats, but everything else stock including the resonator. Made 365hp and 370 tq. to rear wheels. At the same time frame, I had to pass emissions.... So I picked up another stock exhaust, cut out the resonator, and put 2 bullet cats in place. To be honest, there was not much difference in the sound, and no performance difference that I could tell... I even have a stock exhaust with the axle back kit that magnaflow sold. I liked the sound of it, but for my use, and where I live, its just too loud.. Ironically, resonance has never been an issue, but I contribute that to mine being a vert.

FWIW, IMO that LE2 build, (I assume is his custom cam, along with him porting your heads....) with long tube headers, is one of the best values out there for engine performance on a LT1-4. Throw a set of gears, and a higher stall converter in there and with good tires, you can have a 11 sec. car!!
Good luck, and again, I look forward to seeing your results!

 

Quote:

Originally Posted by KyleF

Seems you have no issue spending it elsewhere.

Money is not only spent for HP/TQ. Ease of installation and appearance are also important as well as materials that protect that appearance. Unless "Race Car" and appearance means zero. I just find it odd that you seem to have no problem spending enough money to get to 460hp to the rear wheels "on a C4" but somehow the exhaust seems to bother you.

Wow, where do I start? I guess I will try to break this down and answer in sections, beginning with your quotes.

1. "Seems you have no issue spending it elsewhere." Actually, that is incorrect. I will spend, but I try to look for the best value for my money.

2."Money is not only spent for HP/TQ. Ease of installation and appearance are also important as well as materials that protect that appearance." What is easier to install, then a stock LT1 exhaust? Appearance? That is just an opinion. In fact, you can do a search and you will find some who look for aftermarket mufflers with the black rectangular shaped tips. Some believe that the dual round tips coming out of a rectangular opening is cheap and has that rice look. Myself, I dont care, I like them both. Materials that protect that appearance? Not sure how that applies.

3. "Unless "Race Car" and appearance means zero. " Actually, race car, and appearance means quite a bit to me, but again, so does value for my dollar.

4. "I just find it odd that you seem to have no problem spending enough money to get to 460hp to the rear wheels "on a C4" but somehow the exhaust seems to bother you." At this point, I would like to ask you a few questions
a. What do you think it cost to build that motor? Over the next few days, I will try to add up my receipts, and we can see how close your guess is!!
b. Would you tell me what exhaust system would serve me better? The factory exhaust is stainless steel 2.75 pipes. and they seem to last forever....

In closing, I want to say 2 things,
1. It seems to me, that you "think" I have a ragged out race car and looks or other issues mean nothing to me. If that is correct, then you are wrong. Below, I have posted a picture of my car, so others can decide.....
2. This is my personal opinion, but I do not like the sound of the Corsa system. To me, it has a tinny, raspy, megaphone sound...... I prefer the deep bass american muscle sound. .... But again, that is my opinion.

 

If it helps, I feel the same about the corsa sound as well having heard a few in real life...

 

Glad to hear that....saved $1500 that I can apply to LT headers and custom exhaust work

 

I would love if you could post a sound clip of your car...very similar set up as mine. Also I did custom cam (222/228 .570/.565 110 LSA), heads and ported intake(stock TB). At this point I'm wrestling with rear, D36 w/ Richmond 3.54 gears or a D44 conversion(3.45 gears). The torque converter is another decision, Lloyd recommended a 3200 (originally planned 3.07 gears). I want this to be a ground pounding cruiser, not a drag/track car

 

Do not get me wrong, it sounds good, it just isn't my cup of tea. The sound it produces is a direct result of why it doesn't drone in the first place if I had to guess. If you've heard the newer vettes with the performance oriented stock system it sounds similar. Loud but not chest thumping deep. I can't comment on the C7 I'm referring to C6 like a Z06 level. Not bad but not what I want.

 

I'm in the same boat low, deep sound vs raspy(high whine??). I saw and heard a newer vette racing around the streets once and it had that "super car sound" and I didn't care for it