Remove mid muffler or not?

[Mustang5L5]

I ran that exact setup on my old 2003 GT and loved it. Stock mid-pipe with Flowmaster American Thunder. Plenty of growl but not excessively loud. Does have a bit of drone at 2k rpm but I liked it.

When I finally get tired of the bone stock exhaust on my ‘00 convertible I’ll probably go that route again.

 

[Daryl]

FWIW, but you’ve probably realized already, a cat-back system is installed MUCH MUCH easier with the rear wheels off and ample clearance below.

Mufflers only… not nearly as tough. But should you ever go the cat-back route, you’ll see what I’m talking about very quickly!

 

[Mustang5L5]

If you do a cat-back, chock the front wheels and set a set of jackstands under the rear subframe ahead of the axle. Disconnect the quads (if still there), the main shocks and put a jack under the rear axle and let it drop as low as you can get it before it starts stretching bushings/brake lines/etc. Put 2 more jackstands under the axle there. Then you should have enough room to get the tailpipes up and over the axle.

If your stock cat-back is in great shape, draw some lateral lines through your cut zone (so it can be lined up and rewelded) and cut it off about 5-6" or so from the muffler on a straight section of pipe. If the exhaust is all rusted out/rotted don't bother. Some folks are on the hunt for stock exhaust systems for these cars given they are entering restoration age

 

[Daryl]

If you do a cat-back, chock the front wheels and set a set of jackstands under the rear subframe ahead of the axle. Disconnect the quads (if still there), the main shocks and put a jack under the rear axle and let it drop as low as you can get it before it starts stretching bushings/brake lines/etc. Put 2 more jackstands under the axle there. Then you should have enough room to get the tailpipes up and over the axle.

If your stock cat-back is in great shape, draw some lateral lines through your cut zone (so it can be lined up and rewelded) and cut it off about 5-6" or so from the muffler on a straight section of pipe. If the exhaust is all rusted out/rotted don't bother. Some folks are on the hunt for stock exhaust systems for these cars given they are entering restoration age

Perfect advice. And removing the wheels goes without saying. Gives you that much more wiggle room to finess the cat-back out especially if you’re removing each side in one piece.

 

[PWNY]

I haven't seen what the stock exhaust system looks like in such a long time lol. I agree with keeping the cats so the exhaust doesn't stink. I bought a 2001 f150 recently that had no cats and it smelled horrible. Had a high flow Magnaflow cat put in and soooo much better.

 

[Musturd]

I haven't seen what the stock exhaust system looks like in such a long time lol. I agree with keeping the cats so the exhaust doesn't stink. I bought a 2001 f150 recently that had no cats and it smelled horrible. Had a high flow Magnaflow cat put in and soooo much better.

So many people don’t like the smell of merica in here . No cats is life

 

[shovel]

my credit score is too high to go catless

 

[Musturd]

my credit score is too high to go catless

400 credit score with a 35 year mortgage doesn’t mean your too good for cats buddy .

 

[shovel]

That's.. some kind of guess I guess

 

[PWNY]

The mustang has no cats and it actually doesn't smell bad. The truck on the other hand is a daily and a kid hauler.

 

[Musturd]

The mustang has no cats and it actually doesn't smell bad. The truck on the other hand is a daily and a kid hauler.

That makes sense . My trucks still got the cats too just the cars don’t

 

[RAU03MACH]

None of my cars have cats
just 2 1/2 bbk straight and back half 2 1/2 with Flow masters the way it was meant to be

 

[RAU03MACH]

none on the trucks also

 

[Terrorist 5.0]

I have the middle cats removed and I can tell you that there is little to no smell. So long as your car is running good, the only time you will really notice any smell is if you are standing next to the car and it is not warmed up yet. Glad you found what works for you.

 

[kas_lar]

Hi everyone, just a quick update: Spring is here in Denmark, and the car is running again!
I decided I wanted to update the car and add a bit more sound as well.
Importing a mid-pipe and having it shipped to Denmark is pretty expensive, so I went with a more affordable option and bought a cheap Davico 14539 mid-pipe with cats from Rock Auto. I wasn’t able to install the mid-pipe because of a bent tube, so I had a real mechanic install it. Now the car sounds a lot better and louder. There’s a deep rumble under 2000 RPM, and the idle sound is much better... but... there’s also a bit more drone from the back of the car.


This is my current cat-back system, which has been on for just around 200 miles and a lot of small test drives: flowmasters


I’ve got a few questions for you guys and girls:
I’m thinking of getting another cat-back system to achieve:

1. A louder WOT sound – just louder...
2. Removing the drone from inside the car during cruising between 800-3000 RPM.

Is this possible, and which cat-back system that bolts on should I look into?

 

[Terrorist 5.0]

Hi everyone, just a quick update: Spring is here in Denmark, and the car is running again!
I decided I wanted to update the car and add a bit more sound as well.
Importing a mid-pipe and having it shipped to Denmark is pretty expensive, so I went with a more affordable option and bought a cheap Davico 14539 mid-pipe with cats from Rock Auto. I wasn’t able to install the mid-pipe because of a bent tube, so I had a real mechanic install it. Now the car sounds a lot better and louder. There’s a deep rumble under 2000 RPM, and the idle sound is much better... but... there’s also a bit more drone from the back of the car.


This is my current cat-back system, which has been on for just around 200 miles and a lot of small test drives: flowmasters


I’ve got a few questions for you guys and girls:
I’m thinking of getting another cat-back system to achieve:

1. A louder WOT sound – just louder...
2. Removing the drone from inside the car during cruising between 800-3000 RPM.

Is this possible, and which cat-back system that bolts on should I look into?

Glad you got around to putting the exhaust on. For louder WOT sound, consider an intake plumbing modification. It will give you more sound when you step on it, and it will be more noticeable in the car, which is where you want it. It is also very easy to access so you shouldn’t have any issues doing it yourself.

As for drone, everyone says Flowmasters drone (or chambered mufflers to be precise), but I don’t really notice it in my car. If it is just the sound of the drone then my only suggestion is switch to a different style of muffler, or add those little sound cancelling tubes to the side of the exhaust. I am not sure what they are called, but they basically branch off the exhaust but have a closed end. They help with harmonics. People have had varied success but they do work. If the drone is rattling the interior and that is what is annoying you, I have a post that will instruct you on how to stop the majority of these rattles. It may help your case.

Good luck!

 

[kas_lar]

Thanks, Terrorist 5.0.
Do you have any recommendations for an intake? I currently have a stock intake with a fresh filter.
Do you have any muffler recommendations for a different style?

 

[shovel]

2 years ago I bought a Flowmaster Force-II catback system for my 96 V6 Mustang (converted to accept a GT catback) which came with Flowmaster 50 series mufflers instead of the Super 44's in Flowmaster's American Thunder catback. No drone at all on that car, it's a V6 but at ~2666rpm it would have the same number of pulses per minute as a V8 at 2000rpm.

Flowmaster discontinued the SN95 Force-II system, maybe there's still one out there somewhere. I was looking for one for my V8 but did not look too hard after I saw it was discontinued.

The Pypes mufflers I just installed on my V8 aren't exactly zero drone but they are 90% less drone at their worst than the Flowmaster 44's were on the same car. We all have different ears so it might be hard to describe in text exactly how a mild drone differs from just exhaust sound but it really is a difference like blowing air across the top of a large jar and even when it's a tiny drone it's still a drone. It might not be possible to 100% eliminate it without a separate tuned resonator or J-pipes, or a quiet "turbo" muffler.

My wife's Mustang may not be exactly comparable but I will say it anyway, she has a V6 which necks both cylinder banks down to a Y and then a Magnaflow exhaust splits back with another Y to two straight-through mufflers and two exits. The construction of the Magnaflow mufflers is very similar to the construction of the Pypes M80 mufflers included in the SFM29V exhaust on my V8. I think overall the hardware quality and materials, welding, fit-and-finish on her Magnaflow system is all a full notch better than the Pypes set. The closest equivalent Magnaflow exhaust to SFM29V is #15677; I have not heard that one.

Interestingly the much less expensive Pypes catback has further silencers built into the tips while the Magnaflow does not.

 

[Terrorist 5.0]

Thanks, Terrorist 5.0.
Do you have any recommendations for an intake? I currently have a stock intake with a fresh filter.
Do you have any muffler recommendations for a different style?

I cannot recommend a muffler by experience, only what I’ve seen recommended. I’m not that big on exhaust stuff. I also kept the stock intake plumbing, and paper filter.

What I can tell you is that dumps will give you the very deep sound you are looking for. They say that tail pipes are so that others can enjoy (or hate) the sound, while dumps are for the driver to enjoy the sound. You will have to deal with drone though, and the exhaust smell with dumps is pretty strong without cats.

Personally, I think the SR performance cold air kit looks pretty good, it’s all black like stock, and I believe it is a fender mount, meaning you won’t really be getting all that hot air from the engine bay where most intakes do, along with a bad reputation for that. Just know what you are in for with a fender mount (careful in the rain! I don’t really like the idea of fender mounts, or cold air kits in general but I’m just trying to help )

Keep in mind though, I have good reason for keeping the intake stock, along with using a paper filter instead of the typical oiled one. The oil from the filter coats the MAF and IAT over time and will make them read wrong, to the lean side. If you are willing to clean it every once in a while, go for it. You won’t notice any difference in power (not talking from experience, but highly doubt it, intake restriction on most cars is not the filter, rather the manifold or cylinder heads), but you will hear more of that loud moan when you step on it.

 

[ttocs]

if you do not absolutely hate what you have now, maybe just add some electronic cut outs and then you can make it loud when you want and quiet when you need to. I love my loud button......