Like others posting here and on other forums, MAC axle-back exhausts have been noted for having a teeth rattling drone at 1800-2000 rpm when under load (not all cases ,but there are several posted). Typically, your cruising 2200rpm and above, then slowly decelerate and land in the range where a very loud drone occurs. In my hands (1 day), it's at its worst cruising in 5th on the highway, then running into a wall of traffic that moves between 50 and 60. God it's awful. Sure, I can downshift and drive in 4th until I speed up again, but it seems odd that I need to change my driving habits around a $300 exhaust system. I've scoured the forums and MAC and other brands have been noted for a drone in the same rev range, wtih a varying amount of nuisance.

MAC tech support didn't have an answer after explaining my observations, but quickly turned me over to his boss. He seemed just as puzzled, and indicated it was the first he'd heard of it. He promised to talk to the owner ("Mac") and see what he thought.

I was given a quick return call. The owner indicated the firing order of the engine has changed, specifically cylinders 7-8, and there was 1) nothing they could do and 2) all brands have the same issue.

It was a courteous enough call, but I felt the guy just didn't want to deal with my issue. I got an unexpected statement of "it's a performance muffler, so expect it to be loud." But I responded that muscle cars and mods have been a part of my life since I was 17 (1974), my son has an '04 stang with a MAC and it's fine, and a friend has a '00 with one too and it doesn't drone like this. It IS loud and I love the sound when it's play time, but for daily driving it's major pain. In the ears.

Anyhow, I'm going to give it a week or two, and if I can't deal with the drone or it doesn't improve, I'll unload them on the cheap and get the Flowmasters or Magnaflows. Man....

John

 

soundclips??

 

I hate to hear about the MAC Exhaust, but I can't say your comments on it weren't expected. Anytime you change from the factory exhaust components you risk drone. I've had a BORLA exhaust on one car and another exhaust on a different removed after only a few days due to drone. I don't like droning exhausts, and I would be willing to bet you will be selling your exhaust system soon, since I doubt you will get used to it. The only thing I can think of that might help would be adding some dynomat, or like product, to your trunk area. Of course, that's just addtional expense and likely won't cure your problem, especially if you drive the car every day.

Good luck.

 

The more posts I read like this, the more I am thinking I will just keep my stock exhaust.

 

I'll take the digital camera out tomorrow and have my son along for the ride and pull a short movie. Just learned it had that feature. Sheesh.

John

 

I had a customer remark his flowmasters were Drone Prone from 40-60 Mph a day or so ago!

 

Hey guys, usually I stay out of non Magnaflow exhaust threads but I wanted to add my input

The firing order DID NOT CHANGE on these cars- in fact we had a preproduction car which had the same firing order-

May I suggest the Magnaflow (not packs) to those looking for a quiet performance exhaust- it is not much louder then stock- just deeper and you get the hp gains

The problem is that a chambered muffler uses sound reflection technology in order to quiet a vehicle- which means the muffler bounces the soundwaves to modify them to quiet the car

Unfortunately many waves get bounced back inside the car if the muffler is not designed properly resulting in drone and the problem is only amplified with a chambered muffler

 

I agree, magnaflows are a perfect fit with power, sound and 'non-drone' performance. If you can, get a set of the Magnaflows and sell the MAC's.

-Bryan

 

Like I said, I'm giving this a week or two. If they wear me out and I need to put the stock exhaust back on, I'm already out $300 , unless I can sell them and get a partial return. Where's the best price on the Magnaflows?

 

Suggest away, that's the most likely replacement if I can't find a happy medium here.

Got any pics of that 67 and 66?

 

Same issue I had with my '00 GT - I couldn't stand the drone of the Series 40 2 chamber FlowMasters and took them off after 4 days. I went with the Magnaflows as they were the straight through design AND added hp - which the FlowMaster did not - only noise. The FlowMasters were much "crisper" sounding and at WOT were a "joy to behold" - but in real life transportation they were a pain in the ****....I still have those boat anchors in my garage to this day!!

 

Sounds like BS to me.

 

Same here, I couldn't stand the drone of the Flowmaster 40s on my 01 GT. I replaced them with the Ford Racing cat-back with 2.5" pipes. Sounds great, louder than stock but no drone. Mello deep sound, similar to, but crisper than the Magnaflows.

 

Like I said, I'm giving this a week or two. If they wear me out and I need to put the stock exhaust back on, I'm already out $300 , unless I can sell them and get a partial return. Where's the best price on the Magnaflows?
[/b][/quote]
I had the JBA"S and they "droned" also...it was worse when i added offroad x-pipe. I went back to stock mufflers with my x-pipe,and all is well. No drone,and still get a louder deeper tone from mufflers! Happy this way,especially that mufflers don't prove to be much..if any HP increase!

 

Suggest away, that's the most likely replacement if I can't find a happy medium here.

Got any pics of that 67 and 66?
[/b][/quote]

I suggest the Magnaflow as well

 

I suggest the Magnaflow as well
[/b][/quote]


Here is a teaser- but look for a post soon with a bunch of new pictures I just took-

 

My 2cents, but I still have the stock exhaust and I notice a slightly annoying drone in fifth doing 80mph around 2100-2200 rpms. Car is still completely stock.

 

I suggest the Magnaflow as well
[/b][/quote]

Not sure if it's just on the Roush setup, but I also get a slight drone with Magnaflow. Not as bad as the Flowmasters did, but it turns up now and again.

 

Yeah ALL chambered mufflers drone. Bottom-line. MAC, FLowmasters, Borla, etc. they all drone from around 1900-2100 rpms. There is no fix except to get a quieter muffler or a straight through muffler that won't hurt your poor little ears. And as far as your son not having drone on his '04, that's bs... I for one LOVE the drone and sound of the chambered mufflers. I might be swapping out the 40 series to some 10's(1-chamber) sometime soon.

So if you really can't live with it, then your best bet would probably be magnaflow. They won't be as loud as MAC but they still sound good.

 

Another vote for Magnaflow, no drone.