Automatic Transmission and Exhaust Drone

2015 Silver GT · Mar 29, 2017

Wait, people still buy Flowmasters?

Southview · Mar 29, 2017

The drone happens because the car wants to shift all the way to 6th gear by 40mph at light throttle. Around here most of the streets are 40-45mph. With the shift pattern of the auto,unless you keep it in 5th and keep the rpms up around town,we get a drone. I only get it if I let the trans go to 6th before 40mph which drops the rpm to 1200-1400. Shift points on the auto suck unless in sport mode. Unfortunately he has the base GT. I have no drone other than that. :thumbsup:

BmacIL · Mar 29, 2017

Southview said:
The drone happens because the car wants to shift all the way to 6th gear by 40mph at light throttle. Around here most of the streets are 40-45mph. With the shift pattern of the auto,unless you keep it in 5th and keep the rpms up around town,we get a drone. I only get it if I let the trans go to 6th before 40mph which drops the rpm to 1200-1400. Shift points on the auto suck unless in sport mode. Unfortunately he has the base GT. I have no drone other than that.

No, drone happens because it's a poorly engineered exhaust system. There's several available on the market that will not drone even in that rpm range. You cannot get Corsa's stuff to drone even if you try, for instance. I hear the same of the AWE as I believe they have a similar method for eliminating it.

jasonstang · Mar 29, 2017

Should've gotten the Roush AB. Mine never droned.

LoveMyWheels · Mar 29, 2017

2015 Silver GT said:
Wait, people still buy Flowmasters?

Yep. In a weak moment a German automotive engineer fell for American marketing.
You have to admit that the exhaust's name "American Thunder" sounds deep, classy, rumbling, burbling, growling, but not raspy, not throaty, not barking... just what I wanted. Reviews on americanmuscle.com were reassuring and a $75 mail in rebate added to the temptation.
But the DRONE got my feet back on the ground now, and I appreciate all the members helping to steer me in the right direction. :thumbsup:

LoveMyWheels · Mar 29, 2017

RNstanger said:
I have an Auto with the Solo Axle backs. Been on for almost a year. They sound excellent. Deep growl but quiet when cruising. Absolutely no drone anywhere in the power band. You might want to look into those.

I am very happy to hear from auto-shift owner about this exhaust. I had researched the Solo Mach XV on the internet. The physics behind this odd looking exhaust is proven. I watched all the videos and was impressed. My assumption was, that the J-pipe length was designed to cancel out the traditional V8 drone around 2000 rpm, which should work perfectly. But since you have only one J-pipe length you can't compensate for a drone at the 1250 rpm - 15000 rpm range (down to 2/3 of the sound frequency at 200 rpm) at the same time. But your experience shows that there is no drone at 1250-1500 rpm.
I am starting to I believe that the 1250-1500 rpm drone is a by-product of the muffler design intended to fight the main drone issue around 2000 rpm. Since the Solo's are basically a straight pipe, there is no such by-product.
There is a completely different reason, why I did not move further on the Solos. I saw 2-3 offers by Solo owners to trade their Solo for a stock muffler, because they were planning to trade in their car. I can imagine that a look under the car at the unconventional design confuses the typical used car dealer and my affect trade-in value. But with you positive review I may rethink.

VinnAY · Mar 29, 2017

Southview said:
The drone happens because the car wants to shift all the way to 6th gear by 40mph at light throttle. Around here most of the streets are 40-45mph. With the shift pattern of the auto,unless you keep it in 5th and keep the rpms up around town,we get a drone. I only get it if I let the trans go to 6th before 40mph which drops the rpm to 1200-1400. Shift points on the auto suck unless in sport mode. Unfortunately he has the base GT. I have no drone other than that.

Man you try and tell the M/T crowd this and they flip their lids. :headbonk:

BmacIL · Mar 29, 2017

LoveMyWheels said:
I am very happy to hear from auto-shift owner about this exhaust. I had researched the Solo Mach XV on the internet. The physics behind this odd looking exhaust is proven. I watched all the videos and was impressed. My assumption was, that the J-pipe length was designed to cancel out the traditional V8 drone around 2000 rpm, which should work perfectly. But since you have only one J-pipe length you can't compensate for a drone at the 1250 rpm - 15000 rpm range (down to 2/3 of the sound frequency at 200 rpm) at the same time. But your experience shows that there is no drone at 1250-1500 rpm.
I am starting to I believe that the 1250-1500 rpm drone is a by-product of the muffler design intended to fight the main drone issue around 2000 rpm. Since the Solo's are basically a straight pipe, there is no such by-product.
There is a completely different reason, why I did not move further on the Solos. I saw 2-3 offers by Solo owners to trade their Solo for a stock muffler, because they were planning to trade in their car. I can imagine that a look under the car at the unconventional design confuses the typical used car dealer and my affect trade-in value. But with you positive review I may rethink.

There are at least two companies that engineer their mufflers with the same 1/4 wave resonator capabilities as J pipes and expand further on it, tuning not only to cancel drone but other frequencies that create unnecessary noise in the car.

jasonstang · Mar 29, 2017

BmacIL said:
There are at least two companies that engineer their mufflers with the same 1/4 wave resonator capabilities as J pipes and expand further on it, tuning not only to cancel drone but other frequencies that create unnecessary noise in the car.

I think the thing about quarter wave cancellation is it will also cancel at even multiplication of frequencies right? so if it's canceling at 2000 rpm, it would also get quieter at 4000 and 6000.

TXAG01 · Mar 29, 2017

EcoSwag1990 said:
The Pypes Street Pro axel-back gives that deep rumble but it had zero drone on my auto with 3.15...

Volstang said:
I also have the Pypes Street Pro axle back mufflers on an otherwise stock exhaust on my 2015 GT. Mine is an auto with 3.15 gears. No drone in mine, just a deep muscle car sound and no rasp. I've had several Fox body Mustangs and wanted something that somewhat sounded like the deep, rich muscle car sound I enjoyed in those cars. I'm very satisfied with the Pypes. Not stupid loud, and no drone or rasp.

Same here. :thumbsup:

Commbubba19 · Mar 29, 2017

Get the solo mach xv catback.

I'm running the mach thunder with mak cat deletes and though loud, drone is minimal. if i was running any other aggressive catback the drone would be horrible.

plus solo is much better priced compard to AWE, Corsa, and Borla and just as good quality. Plus the engineering behind the design is top notch. I love the ball/socket design to get the tips perfect.

Jay-rod427 · Mar 29, 2017

jasonstang said:
I think the thing about quarter wave cancellation is it will also cancel at even multiplication of frequencies right? so if it's canceling at 2000 rpm, it would also get quieter at 4000 and 6000.

No. It's not every 2,000 rpm its a multiplication factor.

bobbyh · Mar 29, 2017

I have the FRPP touring on my 2015 GT A6 that the original owner put on and they do not drone at all.

However; they are quite a bit raspy which I personally could do without.

LoveMyWheels · Mar 29, 2017

Josh/AWE said:
Thanks for the kind words!

I am a bit confused, though. There's a solid 20 seconds of driving at 2k rpm and below :shrug:

Simulation of highway driving starts at the :54 mark.

A fun fact: we intentionally develop all of our systems on AT-equipped cars to make sure what you're currently experiencing doesn't happen with our exhausts. Drone zones are much more prominent, accessible, and apparent with autos. We find the hot spots, analyze frequencies, fine-tune the configuration, then decimate them with 180 Technology® addle:

You are right, my statement was not accurate. The video sequence with highway cruising shows the critical drone area around 2000 rpm and indeed covers some seconds under 2000 rpm:
2250 rpm @ 0:54 min (start cruise)
2400 rpm @ 1:00 min
2000 rpm @ 1:05 min
1900 rpm @ 1:10 min
1800 rpm @ 1:15 min
1750 rpm @ 1:20 min (end cruise)

Maybe we can deduct another 100 rpm due to the angle of the camera relative to the gauge. However, the engine speed does not go down to the range 1250rpm - 1500rpm, which is the range where my drone problem exists. For the sake of fuel economy Ford programmed the automatic to shift up early and stay in that very low rpm range in many cruising situations under 50 mph.

kenbidwell · Mar 29, 2017

My Roush axle backs droned terribly. So much so that I returned to stock exhaust. Recently went with Steeda axle backs and still had a small drone problem. Found a custom exhaust shop that put J-Pipes in for me last weekend. I would say that the drone is 75% gone now. Probably would be completely gone but I guessed at the length trying to kill drone around 1500 and around 2200 rpm. Going to shorten the J-pipes next weekend to the correct length for the 2200 rpm drone. I am amazed at how well these work. All in, I am still under half the cost of Corsa axle backs. Love the Corsa's just hate the retail price and I couldn't find any used. Love the sound of my Steeda's .

Automatic Transmission and Exhaust Drone

2015 Silver GT

Well-Known Member

Southview

Well-Known Member

BmacIL

Enginerd

jasonstang

Well-Known Member

LoveMyWheels

LoveMyWheels

LoveMyWheels

LoveMyWheels

VinnAY

Well-Known Member

BmacIL

Enginerd

jasonstang

Well-Known Member

TXAG01

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Commbubba19

Well-Known Member

Jay-rod427

Well-Known Member

bobbyh

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LoveMyWheels

LoveMyWheels

kenbidwell

Well-Known Member