Muffler only question

[zookeeper]

I was under my '88 GT today and found an exhaust leak due to a small split in one of my original mufflers. Anyway, since I need new mufflers, I've been kinda thinking of using my stock exhaust and just swapping on 40 series Flowmasters. But here's my question: I'm really interested in hearing from someone who has done this to hear how loud it actually is. I've heard a local car with 40 series and an off-road H pipe and dumps and it was waaaaay too loud for me. But knowing the cats and small stock exhaust are going to quiet it somewhat, and the fact I love the way Flowmasters sound, I'm hoping it'll be civil enough to at least try it. I've searched but can't find anyone who's just swapped in 40's, but would love to hear some feedback from those who have. Thanks, Jim

 

[85_SS_302_Coupe]

I think it would be more on the quiet side, probably a bit louder than stock but i think that should be expected with most Flows. The stock catted H and 2.25 pipes will help contain it. I don't know if you'll get much experience on this since most people just swap it all out for 2.5 stuff.

 

[zookeeper]

Thanks for the response, I hope you're right about that since I want it a little louder than stock without being too over the top.

 

[85_SS_302_Coupe]

Well, of course it depends on what you think is over the top. If you're really on the conservative side you might wanna look into the 3 chambers instead of 2 chambers just to be safe. Stock mufflers were pretty quiet...i've only owned one that had them but i remember the roar of the engine being louder than the mufflers, and i know 40s will definitely switch that around.

 

[wythors]

Just a thought:

By the time you buy two mufflers ($185-ish) and pay an exhaust shop to hack them in (reducers, clamps, labor time - $120-ish), you're already 3/4 of the way to buying a brand new, stainless steel Flowmaster cat-back system that you can install yourself in 90 minutes in your driveway. Bear in mind that if your muffler is rotted out, the pipes aren't going to be far behind. When I bought my 93 LX in 1999 with 30k on it, the tailpipes had a bunch of rust pin holes in the top of the arch over the axle. If you just do the mufflers, sooner or later the flow tubes or tail pipes are going to need replacing and you're going to be stuck dealing with that. A new stainless system now will save you money in the long run.

In response to your original question about sound, you probably want to go with the 3-chamber mufflers or the Force II cat-back. They give you a nice rumble without being over the top.

 

[88Ttopp]

Dynomax Mufflers

What is the difference between the 3 chamber and Force ll mufflers?

I put a Dynomax super turbo mufflers cat back system on my 90 GT with
stock headers and cats. It had a good tone but was not loud enough for me
and at about 2000 rpm it was to loud in the cab for me .

I like the sound of Flowmasters but how are they for the dreaded 5.0
2000 rpm cab noise? How about some others mufflers for the Fox body's?

Stephen

 

[SteedaGT9150]

flowmasters drone like no other at cruising speeds

 

[2000xp8]

Just a thought:

By the time you buy two mufflers ($185-ish) and pay an exhaust shop to hack them in (reducers, clamps, labor time - $120-ish), you're already 3/4 of the way to buying a brand new, stainless steel Flowmaster cat-back system that you can install yourself in 90 minutes in your driveway. Bear in mind that if your muffler is rotted out, the pipes aren't going to be far behind. When I bought my 93 LX in 1999 with 30k on it, the tailpipes had a bunch of rust pin holes in the top of the arch over the axle. If you just do the mufflers, sooner or later the flow tubes or tail pipes are going to need replacing and you're going to be stuck dealing with that. A new stainless system now will save you money in the long run.

In response to your original question about sound, you probably want to go with the 3-chamber mufflers or the Force II cat-back. They give you a nice rumble without being over the top.

Agreed.
Changing just the mufflers is just plain old unwise.
First off, and offroad pipe with 2 chamber flowmasters is going to be loud as hell.
Make it twice as bad with dumps, you're whole damn car is going to vibrate and rattle.

Buy a 2.5 three chamber flowmaster catback if that's the sound you like.
Probably about 25% quieter than the 2 chamber, but still by no means quiet.

No dumps, they are ghetto.

 

[LX302]

Flowmaster Force II 2.5" Cat-back Exhaust is the way to go in your application.
I had Dynomax Superturbo's on and while not as quite as stock, they droned like hell at 2K RPM.

The Flows with stock headers and an H-pipe have that traditional Flow sound and not obnoxious and they don't drone nearly as much as the Superturbo's.
Hope this helps.

 

[Kman]

Did the exact thing many years ago with my 87 LX, added 40 series Flows to an otherwise stock system. Was throaty but not loud. Since then I added shorty headers, 2 1/2" Mac catted H pipe and 2 1/2" cat back with Flow 40's and is probably slightly louder than previously but IMO not what I would consider loud by any means.

 

[Gearbanger 101]

I like the sound of Flowmasters but how are they for the dreaded 5.0
2000 rpm cab noise? How about some others mufflers for the Fox body's?

flowmasters drone like no other at cruising speeds

Agreed. The interior resonance between that 1,800-2,200RPM range is unbearable at times. The biggest drawback to aftermarket mufflers.

Mac's are no better. It pretty much goes for all chambered mufflers.

That being said, I had a set of strait through Magnaflow's on my last car and it droned along as bad as my Macs did.

I'm actually considering a set of the new Dynomax VT series mufflers as my next buy. Seems like the only answer to drone free operation?

Dynomax® Performance Exhaust | Mufflers | Dynomax VT™ Muffler

 

[zookeeper]

Hi guys, thanks for all the responses. Lots of good points here and let me address some of them. As for the comment that the pipes and and mufflers are in the same, rusty conditon, that's good reasoning, but doesn't apply here. Why? First off, the car is garage kept and living in California, not much external corrosion at all. Also, my wife bought the car nearly new and it was still under warranty when she bought it. About 2 yrs after she bought it, the entire exhaust system (except headers) was replaced by Ford due to a recall. Yes it has many miles on it since then but rest assured it's very solid with the exception of the one muffler. That muffler isn't rusted out, but rather has a split seam, so I don't think it's unwise at all to just replace the muffler. Also, I already know what 50 series Flows sound like, and to me they are a bit tame. My wife's '69 Corvette withe a 427 has them and while they sound nice, they also sound, well, tame. I have heard a Fox-bodied Mustang with 40's and a 2.5" off-road H-pipe and agree they are a bit more than I want. But I was hoping to hear some real-world experience from someone who has just replaced to the stock mufflers on the stock system with 40 series and kept the rest. Drone? I can deal with it, after all it's not like I'm driving the thing all day on the freeway, I just want something with some bark to it without sounding like my wife's Corvette (too quiet) or the dumbass up the street with the primered 5.0 and open headers. Thanks guys, I do appreciate the help .

 

[zookeeper]

Did the exact thing many years ago with my 87 LX, added 40 series Flows to an otherwise stock system. Was throaty but not loud. Since then I added shorty headers, 2 1/2" Mac catted H pipe and 2 1/2" cat back with Flow 40's and is probably slightly louder than previously but IMO not what I would consider loud by any means.

Somehow I missed your post. THANK YOU!! This is what I wanted to know and it sounds like just what I wanted. I think this is just what I want, and since I can do all the work myself ( I did the entire exhaust install on my '68 fastback) it'll just cost me mufflers and time. Thanks again!

 

[Kman]

No problem. Keeping the cats will definitley keep the sound level down significantly especially if you are still using the stock 4 cat pipe.

Jack