Exhaust Systems

[jjstang 51]

I assume it depends on the application, but I notice that drag race cars do not run anything past the headers.  If running a system would make more power or make the car faster, they would??? 

[DocWok 30]

On 7 April 2017 at 8:01 PM, barnett468 said:

the term "nice sound" doesn't mean anything . if you want it loud and obnoxious and want it to drone inside the cab, get flowmaster single chamber exhaust.

magnaflows are straight thru and make more power but are quieter inside the cab.

you must put a cross over pipe on it to ruduce drone.

2 1/2" is minimum for optimal power and 3" is too large unless you have over round 550 hp, plus as was mentioned, 3" won't be easy to fit . 2 5/8" is a god size but some shops don't have it. 

,

 

 

Could someone advise me where l could buy a 2 5/8" exhaust kit?

l've never seen one advertised anywhere for a mustang.

[barnett468 418]

3 hours ago, jjstang said:

I assume it depends on the application, but I notice that drag race cars do not run anything past the headers.  If running a system would make more power or make the car faster, they would??? 

yes it does depend on the application . those headers are designed/tuned for that one particular application where the engines constantly run at max rpm with absolutely zero regard for how much power they make under say 5000 rpm because they will never ever run there . the fact is that if you put john forces headers on your engine it would produce LESS power than a set of smaller and longer headers.

when you talk to knowledgeable engine builders and tuners like myself and others whom know even more than i do, we typically talk about torque and averaged power over the rpm range that a vehicle will be used, and since street engines also have to perform well at idle and the lower rpm ranges, they require different  setups than a drag car .

[barnett468 418]

1 hour ago, DocWok said:

Could someone advise me where l could buy a 2 5/8" exhaust kit?

l've never seen one advertised anywhere for a mustang.

There are no kits for 2 5/8" or 2 3/4" and I never said there were . It would have to be custom made . Exhaust pipe suppliers have the pipe and summit racing also carries the 2 3/4" from a few different mfg's, and the fact is that if 2 3/4" was an extremely unusual size, they wouldn't carry it because they wouldn't sell enough of it to justify stocking it.

https://www.summitracing.com/search/part-type/exhaust-pipes-straight/outside-diameter-in/2-750-in

[RPM 1,190]

Ladies, you're not helping the OP in his quest for answers. Keep your bickering at home.

[barnett468 418]

On 4/7/2017 at 3:07 AM, 390mach1 said:

I have a 393W stroker, no staggered rear suspension. I'm looking for something with nice sound and also I would like to have the pipes tucked up nice to the floor so it doesn't hang down.

If you have long tube headers with a 3" outlet, I would run a piece of 3" pipe off the headers that was long enough to make the distance from where the tubes converge to where the pipe ends, 18" . I would then taper it down to 2 3/4" with a cone instead of an abrupt step and use 3" magnaflows with 2 3/4 to the rear with some tips that at least equal 2 3/4" pipe in area . I would also use a cross over as I and some others mentioned.

 

 

 

 

 

[Max Power 74]

David Vizard always has interesting things to say about exhaust systems and zero loss systems:

http://www.superchevy.com/how-to/exhaust/0505phr-exh/

If there is one thing you should take away from his work, it's that secondary pipe size isn't really where loss occurs as much as header collector length and muffler design. All those 3" pipes mean nothing if the rest isn't optimized, and like a garden hose, as system only flows as well as its tightest restriction, so if your 3" system isn't mandrel bent, you have restriction.

For street cars, exhaust is almost always a compromise. Practicalities like sound volume, heat generation, fit, expense are all factors in giving up 5hp here or there in the interest of sanity. As such, my system is the same. 398 CID, Heddman shorties, mandrel bent 2.5" x pipe, going through some sort of Dynomax muffler with a flap in it to eliminate drone, out through mandrel 2.5" Flowmaster tailpipes into custom made 2.5" splitters, ala Mach 1 style. It ain't perfect, but my tires are already my fusible link, I don't need more horsepower.

[Machspeed 219]

27 minutes ago, Max Power said:

David Vizard always has interesting things to say about exhaust systems and zero loss systems:

http://www.superchevy.com/how-to/exhaust/0505phr-exh/

If there is one thing you should take away from his work, it's that secondary pipe size isn't really where loss occurs as much as header collector length and muffler design. All those 3" pipes mean nothing if the rest isn't optimized, and like a garden hose, as system only flows as well as its tightest restriction, so if your 3" system isn't mandrel bent, you have restriction.

For street cars, exhaust is almost always a compromise. Practicalities like sound volume, heat generation, fit, expense are all factors in giving up 5hp here or there in the interest of sanity. As such, my system is the same. 398 CID, Heddman shorties, mandrel bent 2.5" x pipe, going through some sort of Dynomax muffler with a flap in it to eliminate drone, out through mandrel 2.5" Flowmaster tailpipes into custom made 2.5" splitters, ala Mach 1 style. It ain't perfect, but my tires are already my fusible link, I don't need more horsepower.

Yes, and I find it intriguing that people spend hours straining their brains and their wallets in an attempt to save 5HP, if that, to put 3" pipes on their "street" cars. If this were something that you took to the drag strip on a regular basis perhaps, but for street driven applications, I just don't see it being worth the hassle. Maybe I'm just an old fart, as I once strained the brain and the wallet on things like this too....I don't know. 

[bryonbush 85]

i have flowmaster 40's with my 351w and dougs headers. While at idle it sounds great, any driving other than around town will make your ears ring by the time you get home. im looking into some magnaflows but with a move in the near future, that expense may have to wait. 

[rwcstang 201]

Here's my setup, 

Ignore the dirty chassis... lol 

 

 

 

[RPM 1,190]

What dirty chassis?

[BuckeyeDemon 211]

On 4/9/2017 at 2:15 PM, LSG said:

 And our friend is wrong about it being tough to fit. It fits fine, it is tight,but you CAN do it, Just get the Magnaflow stuff and put it on. I would recommend reversing the bolts on you rear spring shackles, it give you more room for the 3 inch pipe, AND for your fingers as you are working. If you look around this site, you should find a thread from one of our men who made his own twin outlet tips to fit his 3 inch exhaust. Looked just like stock, only bigger. You might also check Buckeye Demon's build thread. He has a 351W based engine with a custom 3 inch system. Looks nice. And I haven't heard him complain that it was 'too big'.   LSG

i recall reading of issues with the 3" magnaflow kit in the past on these cars requiring rework to get it to fit.  I don't know the reasons why. 

Have you personally installed a 3" system on a 65 to 70 mustang?  I'm curious to what kit it was (or maybe it was your custom design) and how many hours of labor you had in it.

I personally don't think it's easy to fit on these cars and the result is more time. If someone else is doing the labor, TIME = MONEY.   Of course it may not take extra time, if the installer allows it to hang down, or hit the shocks, rearend, leafsprings, etc.

It's true, I haven't complained about the 3".  However, I haven't performed a back to back test with another size/configuration to be able to say if the 3" is hurting me for my application.  One annoying thing i hate on the internet are reviews by people with nothing to compare it to. 

With all that said, I'm building full 3.5" exhaust on my Falcon. 

[latoracing 256]

22 hours ago, BuckeyeDemon said:

With all that said, I'm building full 3.5" exhaust on my Falcon. 

^^^^^ This sounds like fun! ^^^^^^

In having just "a few" hours involved in constructing my exhaust system, I can sympathize with the people who attempt to market exhaust systems to the public on a mass production scale. Ensuring that these systems fit without modifications takes a lot of engineering. I have seen a Magnaflow 2.5" system installed on a '68 coupe, which fit nicely, but have not seen a full 3" over the axle system. Keeping an exhaust system tucked up tight to the chassis is another difficult task, especially with some full length headers and larger pipes. 

I went with Spintech oval x pipe (3" sized universal kit) with some custom spec (read extra baffles and larger case) mufflers. This had better sound good, cause it sure isn't a quick install lol. And I sure would not want to be paying someone to build all of this, I'd be broke...

[390mach1 49]

Thanks for all the help guys I'm probably going to go with the Magnaflow 2.5" Kit and see if I can put a Mach 1 style Tail pipe on it.