Mandrel pipes /magnaflow/flowmaster crazy?

[bartlett]

today I took my car into a local hotrod exhaust shop and left there a little sticker shocked and maybe suckered alittle ..

  He talked me into mandrel bent system with magnaflow mufflers and flanges so it can be taken off and on for $1,000 out the door....

  I went in with the thought of going with my like new flowmaster 10 series mufflers and 2 1/2" pipe with a crossover  . figured $300-400 max to get that done ...  He quoted me $700 for crushed pipe to get that done ....

  He was very sturn about not using the flowmasters because they suck after 300hp,and how much hp I would lose blah blah blah ....

IS 1,000 for a header back system with a cross over,flanges,02bung ,magnaflows, over the axle and dropped out pointed down by the rear fenders/bumper fair?? or crazy ? Its with 2 1/2 14 gauge pipe....

Sitting at home with the car there, I keep thinking $1000 for 20ft of pipe and a few welds ?? uhhgggg

[amdscooter]

I got a quote from a shop that does a lot of local Shelby club work about 6 weeks ago before I pulled my motor. Estimate I got was $650 out the door for 2.5" aluminized stainless all the way to the rear bumper with a set of Flowmasters. $550 for 2.25". I was actually planning on switching to Magnaflow's or something similar myself on interior noise recommendations alone from My427stang.

[machoneman]

Depends a lot on the area your in and what local labor goes for, as in major markest the rates are high (overhead + labor I should say).  A grand doesn't seem way out of line, especially if they actually did mandrel bend all the pipe sections.

That said, I have Hooker's off-the-shelf  madrel bent 2.5" pipes on my '70 Stang (muffler thru to the rear valence panel) and they were less than $200 IIRC. Add in Hooker's bolt-on 3.5" header collectors, Hooker's H-pipe kit, two old school Flowmasters and some straight 2.5" sections (H-pipe to front of mufflers) and I think it's about $400 in materials alone. And that was done some years ago; prices for all the pieces are higher today I'm sure.   

One more thing; he did b.s. you on the 300+ hp drop off. One trick when I'm confronted by this kind of, ahem, "salemanship" is to ask what range of mufflers does he most often sell? The likely answer is Borla, usually the most expensive brand and only Borla! 

Btw, a few good muffler tests are on the 'Net...I'll see if I can find one in my long its of Favorites and post it here. One of the dyno tests (think it was 15+ mufflers) showed only a 2-3 hp and 3-4 lbs/ft torque among all the leading suppliers!

 

[machoneman]

Two muffler comparions:

http://fullsizebronco.com/forum/showthread.php?t=193545

Sorry, but one will need to click down the page aways to get to the good stuff. The first chart of cfm flow is now pretty old (over 10 years IIRC) doesn't show any Boral stuff, but clearly identifies Hooker's Max Flow as the best flowing at the time.

That said, the next chart shows a 370 hp SBF undergoing a variety of muffler dyno tests. Note the very small differences in both hp and torque, especially  at high rpms where a poor flowing system would show up. One really needs a full race type muffler (think; loud!) for over 500 hp if one doesn't want to run open headers.

[jayb]

Are you able to weld?  If so, you can just buy the mufflers and the pipe, including mandrel bent U bends or J bends, and cut and fit the exhaust system yourself.  Not only will you save some money, but you'll learn a new skill doing it. 

If you can't weld, why not take this opportunity to learn?  It isn't that tough.  You can probably get set up with an oxy-acetylene torch setup for around $400, so you should be able to get the torch setup plus all the materials you need for the exhaust system for less than the $1000 you were quoted.  Then you'll have the torch for any future requirements.

I rationalize new tool purchases like this all the time 

[ScotiaFE]

X2 with Jay's thinking, Although I would be thinking electric welder.
The hardest part of building your own system is cutting the pipe.
You will need a saw. A hacksaw will not do. Your arm will give up. LOL
And a cheap ass welder if you don't have one.
For a 1000 bucks you can buy a welder and a saw and all the parts you need to make your own.
When your ready for another try at it you will think: I can do better than those hacks.
A lot of people think you must have lots of money, you have a Kool old cars.
They don't think about all the years it took to collect the junk. 

[My427stang]

I run Borla Pro XS on my 489, they run good and got rid of the horrible drone I had from Flowmasters prior to the swap.  After the swap I was surprised to feel more power everywhere, it was win/win for me

I recommend that you go mandrel bent and anything but Flowmasters.  I like Pro XS, but Magnaflow or Hooker Max Flow all use the same design and will work great.

I'd also recommend you build your own, buying pieces isnt that expensive, and I'd even consider 3 inch with your build.  I run three inch duals on all of mine, including my truck.

As far as mig versus torch, I wholeheartedly recommend using a torch first if you are learning to weld. Once you learn to manage heat, you can weld with any other type of welder.  plus you have a torch for heating stuck things later

Another option would be to take a welding course if you do not know how to weld, and buy a cheap Mig and chop saw, it's easy to learn and you can build something very nice

...or of course you could pay the bill and pick it up at the end of the day, there is something good about that too!

I would consider 3 inch though for a hot stroker FE  if it is doable and then hold him to very high standards.  I think the cost isn;t unreasonable, it'll take a full day to do it all, he is adding flanges to section it so you can drop it, and I assume the x-pipe and mufflers are included? 

It's not cheap, but the guy has to make money and if its nice, it'll only be uncomfortable to you once.

[bartlett]

Thanks guy's , now I feel worse !  I consider myself to be a pretty good fabricator. I Have a set of torches,I have a cut off saw, I have a miller 210 ..     I realy thought about buying the flowmaster x pipe do it your self kit.  Probly should have done that. Kinda to late now. I shook his hand and told him to get it done. I know he started working on it already. Told me it would be tuesday before its done.  IM not sure why but I was alittle intimidated to buy a universal type kit and have it not work out. The part I was worried about is the over the axle area. I do like that he is going over the axle into the rear wheel well and dropping it  down twards the ground right at bumper height. (you wont realy see the pipe)

 I am sure I would not have thought about adding flanges, I like it can be removed.  Im going to bite the bullet this time. Next project Ill try it myself.....  maybe ....

[amdscooter]

Not trying to pimp a shop here so if this is a forum foul LMK and I'll happily delete. But I found the Borla Pro XS here: http://www.streetsideauto.com/p/borla-borla-pro-xs-40352/ for $70 + shipping. Lowest I've seen it.

[Qikbbstang]

Kind of vague on the discription but from what Ive leaned (by ear) is where the exhaust pipe terminates and where it is aimed make all the difference in the world.  Aiming exhausts at the pavement can make a hell of a mess as the sound waves bounce back off the pavement and hit the underside of the car making a hell of a racket inside.  I also found (by ear) that getting the exhaust tip beyond the car's shell is important. I have a strong feeling sound waves don't go out of the pipe like a sawed off shotgun but rather like a mist nozzle that spreads wide freaking instantly out of the pipe - meaning if the body-shell of car is in close proximity to the ex-tip it can reverb and make a hell of a lot of noise in the car. If the pipe extends beyond the shell a just couple inches the reverb does not work on the shell like a drum.  I put extensions on the exhaust tips to just clear the shell and the sound inside the car went to way less then half the noise inside the car. The car was my 300ZX and I had Ford Racing Borla Fox Body Mustang GT mufflers (picked up at clearence sale) on the rear. Getting the exhaust termination beyond the rear valence did the trick.

The part I was worried about is the over the axle area. I do like that he is going over axle into rear wheel well and dropping it  down towards ground @ bumper height. (you wont realy see the pipe)

[ScotiaFE]

I have to agree with BB here.
The pipes should run out past the rear of the car for the most noise suppression inside the car. What's behind you does not matter. lol
Dumping into the wheelwell is like dumping into an echo chamber.

[bartlett]

they dont dump into the wheel well , the pipes bend up the well and drop out the rear bumper area and point about 3-6 feet back of the rear bumper.... Ill post pics when done ...

[My427stang]

Kind of vague on the discription but from what Ive leaned (by ear) is where the exhaust pipe terminates and where it is aimed make all the difference in the world.  Aiming exhausts at the pavement can make a hell of a mess as the sound waves bounce back off the pavement and hit the underside of the car making a hell of a racket inside.  I also found (by ear) that getting the exhaust tip beyond the car's shell is important. I have a strong feeling sound waves don't go out of the pipe like a sawed off shotgun but rather like a mist nozzle that spreads wide freaking instantly out of the pipe - meaning if the body-shell of car is in close proximity to the ex-tip it can reverb and make a hell of a lot of noise in the car. If the pipe extends beyond the shell a just couple inches the reverb does not work on the shell like a drum.  I put extensions on the exhaust tips to just clear the shell and the sound inside the car went to way less then half the noise inside the car. The car was my 300ZX and I had Ford Racing Borla Fox Body Mustang GT mufflers (picked up at clearence sale) on the rear. Getting the exhaust termination beyond the rear valence did the trick.

The part I was worried about is the over the axle area. I do like that he is going over axle into rear wheel well and dropping it  down towards ground @ bumper height. (you wont realy see the pipe)

Correct in theory and certainly not wrong that a outlet under the car will reverb more than one out back, but don't blame the exits alone, Flowmasters do resonate

Matter of fact, in my experience the SAME exhaust design with just a muffler swap made a dramatic difference.

I wont use a Flow anymore, the difference between an absorption muffler and  a reflective muffler, which even Flowmaster calls "resonant technology", is night and day

The sound reflective mufflers change the noise into mechanical energy and heat.  That mechanical energy at some point will resonate the case.  Ironically I could live with the mufflers on a 433 inch motor, 3.70s and a 4 speed, when I went 489 inch and changed the gearing, I couldn't even think, because it put the resonance in a load/rpm situation that was right where I drove

Absorption mufflers don't do that, however, they potentially wont last as long either.

As far as paying the guy bartlett, nothing wrong with that.  I am a long time mechanic/bodyman, did it professionally for 1/2 my life, and I elected to pay someone to do the paint on my truck.  Sometimes you can't do everything, and if that dual exhaust is done right, you chose a good path

[ScotiaFE]

There are a lot of factors that effect how much sound is in the car.
A small comparison is my Fairlane and Mustang.
The Fairlane has sound mat and a nice full interior and is very comfy.
Even with open headers as it it now (set up for some track time) it's really not that loud inside. Relatively speaking. LOL
The Mustang (when last out) was a basic shell with a piece of carpet and two little seats and just the minimum interior. LOUD inside!
It sounds like your sitting in a steel drum and there's 8 guys pounding on it with sledge hammers.
The Mustang when it comes back out in version 5.1.1, will probably be even louder.

[My427stang]

You are certainly correct! 

I just get very specific when it comes to resonance, it doesn't come out of a tail pipe, it comes from the body of the muffler itself.

So the sound I am looking to control could have tailpipes 3 blocks behind you on a trailer, and the mufflers under the floor would still boom at a certain rpm/load/volume.