Ford 5.0 muffler conundrum

School me. Point me to articles or videos. Whatever it takes. I'm a sponge awaiting a river of knowledge.
 

Say what you will about Motortrend content, but I get a lot of good theory from the various exhaust shootouts they do on Engine Masters, if you have access.  They tend to focus on how exhaust choices affect horsepower and efficiency (and don't touch on sound quality) but it's taught me more than any single source.  If you want to know what various mufflers sound like though, searches on YT is where it's at.

I didn't see you mention you head/cam/intake combo, but if you're running cast exhaust manifolds I'm guessing this is a fairly mild build.  With that in mind I'd agree with others here that you probably don't need a dual exhaust unless you're looking for that sound/look.  But if you're under 400 HP and don't plan to RPM your motor can save some money on exhaust pipe and run a healthy single muffler system without any issues.

I also have a Falcon ('67 wagon) so I will share that I used to run a single Dynomax VT on my 289, which is kinda like a cheap variable tone muffler that uses a flapper valve that opens at full throttle. It sounded pretty mellow at light throttle but when you floored it, things got plenty loud!  It was awesome and all kinds of stupid fun at stoplights, but ultimately it was a bit too raspy for my tastes. Also I found that I got tired of it anytime I had to dip into the throttle in regular driving situations (like climbing a long hill) so I took it off for now and went back to a generic turbo style muffler (Summit branded 2 1/4" I think) which TBH also sounds pretty healthy when you get on the throttle. But I do plan eventually to add the Dynomax VT back along with a a small glass pack (as a resonator) to tame the open throttle sound a bit. Short of running an electric exhaust bypass of some kind I think that will be the Goldilocks solution for me.

Also I haven't really found drone to be an issue with the Dynomax muffler nor any of several no-name turbo muffler setups I've used over the years. Unless you're planning on a chambered flow master type exhaust or an aggressive cam, I wouldn't worry about it. Regardless, if drone becomes an issue on your application you can always tune it out with a Helmholtz resonator.

Looking forward to how you get on with your SBF swap!

Way back when I had my 1993 Mustang GT, I ran Flowtech Warlock mufflers. The had a bypass cap that you could remove which basically bypassed the muffler. Of course they were dumped right at the rear axle. The drone was horrendous. Definitely run the exhaust out the back.

For nostalgia, how about some Spintech mufflers? 

Well, this certainly is a topic, isn't it?  I guess I was light on the details. A few pics for your enjoyment.

Though the engine looks impressive, I suspect it isn't particularly rowdy. The short block was rebuilt and didn't see much use. The cam is a total mystery.Performer intake, Edelbrock AFB carb, Pertronix ignition. It had headers but they won't fit my application.  Can't say I'm unhappy as I find headers to be more problems than they are worth. The heads are "Roush" world heads that mimic what the GT40 ones are. They are cast iron. The oil pan was on it. Fancy Holley fuel pump. Roller rockers. Dude even sprung for an Edelbrock water pump but it didn't look trustworthy due to the goop I found in the cooling system. This came out of a Mustang that was getting a Coyote swap. I heard it run on video, but that's the extent of what I know about it. Oh, it had a no-name gear drive in it that I removed and replaced with an Edelbrock timing kit.

I used a Magnaflow on a 5 cylinder Audi I had and it sounded really good, so it's a brand I'm familiar with.

I had not considered a single muffler as I wasn't sure anything other than stock was available.

The 66-70 Falcon shares almost nothing with the Mustang. It's a Fairlane with a few inches missing between the wheels. 

ddavidv said:

 the engine looks impressive, I suspect it isn't particularly rowdy. The short block was rebuilt and didn't see much use. The cam is a total mystery.Performer intake, Edelbrock AFB carb, Pertronix ignition. It had headers but they won't fit my application.  Can't say I'm unhappy as I find headers to be more problems than they are worth.

 Once you fire it up, I can impress you with my ability to identify a cam duration and lobe separation by the sound.  Ok, not really, but I can get darn close.

Headers can be a pain, and I wouldn't worry about them on a mystery engine.  As with everything we've kinda mentioned, it's all relative to what you want.  Over on another forum I'm involved with a thread where the guy INSISTS his 496 absolutely needs dual 3" straight pipes to maximize power on a weekend driver.  We can't seem to explain to him that absolute maximum power doesn't mean anything if you lose torque and your hearing.

So much of the aftermarket is focused on "up to 15 more horsepower," and people will shell out cash.  I prefer "up to 15 more years without needing hearing aids" instead of 15 hp.

ddavidv said:

I had not considered a single muffler as I wasn't sure anything other than stock was available.

Absolutely!

The aforementioned Dynomax Super Turbo comes in a transverse 1-in, 2-out version:
https://www.summitracing.com/parts/wlk-17739 

As does the symphonic (but heavy, expensive, and ugly) Hooker Aero Chamber:
https://www.summitracing.com/parts/hok-21729hkr

If you search by application using something like a '94 Camaro you will get more transverse-style options, but these two are my favorites.

Mrs Monohue's dad offered us a very clean '67 Fairlane wagon for cheap money.  Maybe it is time to make some garage space and jump on that thing.

Curtis73 (Forum Supporter) said:

I would start trolling google for "mustang GT exhaust sounds" and you'll find eleventy quillion videos.  And trust me on this:  If the video starts looking like the first picture, don't waste your time.  WAY too close.  No one will listen to your exhaust from 3' away, and the recording will sound like snot.  If it starts looking like the second one, watch it.  That's how you and everyone else will experience it.

Is that your van Curtis?

Very nice.

I just put one of these on the Miata.

https://www.summitracing.com/parts/sum-631125-xl

Ho-Lee-Mama, it is nigh perfect.

Loud enough to produce a nice tone, but pretty mellow.  Louder at WOT, and, most importantly, no drone.

I just pulled a chambered muffler off, as the car will see more daily type duty again, and anymore I don't feel like putting up with the drone.  I LOVE the sound of the chambered (i.e. flow master type - and I've used the cheapo Summit ones and Flowmaster) through the gears, just didn't feel like having my cranial matter turned into pea gravel (the rocks in my head now are fine, thank you...).

The reviews on it are spot on, and I'll be adding my 2 cents as well. 

Definitely worth a look.

These are the manifolds I bought.

The good part is they flow far better than the stock ones. The bad part is they exit weird and require a matching head pipe if doing a 'stock' exhaust kit for a hipo 289. While they make a head pipe for a Mustang, they don't make one specific for the Fairlane/big Falcon chassis and I have no idea if it would fit.

If I knew this part would work I could make whatever I want downstream. Magnaflow makes a Mustang dual kit that includes this head pipe, but...Mustang.  CJ Pony Parts is just a half hour away. I hate to be the guy that tries to return something like this when it doesn't fit. 

The 1977 Granada I had with a 302 used the same style manifolds, but I don't know if that y pipe would fit, or if you could even find one.  

I'm not sure when ford stopped using that style manifold, but it made its way onto other models with the 302, so you may be able to fine one that works for your application. 

I prefer the Dynomax Super Turbo for drone free driving, I have also used the Flowtech Afterburner if I want a louder but not Flowmaster 40 loud exhaust, but that is now only available in 3" if I recall. 

I would think the Y pipe would fit damn near anything because those manifolds were made for an early Mustang, which is pretty much as small and cramped as you could get.

QuasiMofo (John Brown) said:

I prefer the Dynomax Super Turbo for drone free driving, I have also used the Flowtech Afterburner if I want a louder but not Flowmaster 40 loud exhaust, but that is now only available in 3" if I recall. 

 

I had a Dynomax Super Turbo on my E36, still had drone.

Wonder if case length makes a difference.  18" case on new muffler, 13/14 on the others.

Your manifold choice will limit you to right at 300 flywheel hp.

i would (and will) do a custom 2 1/4" to a well made Y to 2 1/2" into a single cheap Summit "hemi" length muffler for more quite or "turbo" for a bit more sound. The 2 1/2" will go over the axle.

The key is mandrel bends! Muffler shop crush bends will kill it.

That said the Mustang stuff of similar year range will be a good start

You might be surprised how well the "house" brands at Summit and Jegs work at your power level.

BTW I have Magnaflow 3" over the axle and around a watts link on my very low 68 Mustang.

Different car but similar power level. I have dual 2.25" with a Y into 2.5" into highflow cat into Magnaflow. Cat is right after the Y and the Magnaflow is right before the rear exit. It's got plenty of growl at WOT but not too bad cruising. Not droney.

I used to have a 289 with Flowmaster 40s and turndowns. I can highly recommend not to do that

Lawrence LT Tolman has a YallToob channel that has a couple videos on dreaded drone. I rewatched them last night researching this post. I think that you will enjoy them.