lost low end torque
Senior Member
Joined: May 2007
Posts: 1,413
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From: Iowa
You've got a pretty common misconception regarding "straight through" mufflers and their "superior" performance over a chambered muffler. Straight through mufflers don't flow straight through like a solid pipe or there would be no noise reduction. They're all louvered and they are designed to direct flow into and around the packing in order to suppress sound, and this causes a very turbulent flow of gas. Also those mufflers are rated in CFM rating using cold air blown in a steady stream, which is very different from the hot pulsing gas stream that our engines produce. Well designed chambered mufflers actually increase scavenging from the exhaust system and subsequently increase exhaust velocity and flow - You can tell me about all the people on this forum with stories about decreased performance from FM systems, but I'm willing to bet there are a whole bunch who love them as well. Don't take my word for it, go to any Fun Ford Weekend event and look under some of the cars in the classes that require mufflers and you'll be surprised to see just how many are running the "Dreaded Slowmaster", and that includes Tough Truck which is dominated by the Blue Oval...
Here's the Magnaflow ---
Mmm... Looks pretty straight through to me. Yes, with ceramic packing for sound dampening. Looks like it'd flow pretty damn well. If you dropped a bag full of cotton ***** in there, it doesn't look like you'd have any trouble forcing them out with an air hose.
Here's your Flowmaster ---
Huh... Look at all those "dead ends" and "blockades" known as baffles... Yes, with all those extra blockades errr, I mean baffles for sound dampening. Now if you dropped a bag of cotton ***** in there and tried to use an air hose to blow them all out, you'd still have quite a few stuck in there.
Chambers help exhaust scavenging? Huh, well I guess that's why I see so many "Flowmasters type" mufflers on professional race cars, drag cars, prerunners, snowmobiles, ATVs, bikes, and sled pullers around the world... Chambers work a lot better than their tuned straight through exhausts... NO!
And as far as Flowmaster being popular everywhere, it's because people love the loud aggressive Flowmaster sound!!! It's a "household name" when talking about aftermarket exhausts. Not because it's a "great performance exhaust".
Heck, even Mike Troyer recommends anything other than a Flowmaster...
Yes, I'm sure there are a lot of people happy with their Flowmaster exhaust. However, I have never seen so many complaints about "lost horsepower", "lost torque", "can't spin my tires anymore", ect. from any other brand.
Lets look as some pictures...
Here's the Magnaflow ---
Mmm... Looks pretty straight through to me. Yes, with ceramic packing for sound dampening. Looks like it'd flow pretty damn well. If you dropped a bag full of cotton ***** in there, it doesn't look like you'd have any trouble forcing them out with an air hose.
Here's your Flowmaster ---
Huh... Look at all those "dead ends" and "blockades" known as baffles... Yes, with all those extra blockades errr, I mean baffles for sound dampening. Now if you dropped a bag of cotton ***** in there and tried to use an air hose to blow them all out, you'd still have quite a few stuck in there.
Chambers help exhaust scavenging? Huh, well I guess that's why I see so many "Flowmasters type" mufflers on professional race cars, drag cars, prerunners, snowmobiles, ATVs, bikes, and sled pullers around the world... Chambers work a lot better than their tuned straight through exhausts... NO!
And as far as Flowmaster being popular everywhere, it's because people love the loud aggressive Flowmaster sound!!! It's a "household name" when talking about aftermarket exhausts. Not because it's a "great performance exhaust".
Heck, even Mike Troyer recommends anything other than a Flowmaster...
Yes, I'm sure there are a lot of people happy with their Flowmaster exhaust. However, I have never seen so many complaints about "lost horsepower", "lost torque", "can't spin my tires anymore", ect. from any other brand.
Here's the Magnaflow ---
Mmm... Looks pretty straight through to me. Yes, with ceramic packing for sound dampening. Looks like it'd flow pretty damn well. If you dropped a bag full of cotton ***** in there, it doesn't look like you'd have any trouble forcing them out with an air hose.
Here's your Flowmaster ---
Huh... Look at all those "dead ends" and "blockades" known as baffles... Yes, with all those extra blockades errr, I mean baffles for sound dampening. Now if you dropped a bag of cotton ***** in there and tried to use an air hose to blow them all out, you'd still have quite a few stuck in there.
Chambers help exhaust scavenging? Huh, well I guess that's why I see so many "Flowmasters type" mufflers on professional race cars, drag cars, prerunners, snowmobiles, ATVs, bikes, and sled pullers around the world... Chambers work a lot better than their tuned straight through exhausts... NO!
And as far as Flowmaster being popular everywhere, it's because people love the loud aggressive Flowmaster sound!!! It's a "household name" when talking about aftermarket exhausts. Not because it's a "great performance exhaust".
Heck, even Mike Troyer recommends anything other than a Flowmaster...
Yes, I'm sure there are a lot of people happy with their Flowmaster exhaust. However, I have never seen so many complaints about "lost horsepower", "lost torque", "can't spin my tires anymore", ect. from any other brand.
Technical Article Contributor
Joined: Aug 2006
Posts: 7,862
Likes: 0
From: Northern California
7lug, thats an argument you will never win. Put a straight through muffler like magnaflow or dynomax on a dyno against a flowmaster, the flowmaster will lose every time. want proof? here ya go....
Now, if you are just after sound, yes flowmaster is probably the best (i think they sound amazing in the higher RPMs). But a straight through like dynomax sounds great at idle and lower RPM, which is where a truck should spend most of its time.
Now, if you are just after sound, yes flowmaster is probably the best (i think they sound amazing in the higher RPMs). But a straight through like dynomax sounds great at idle and lower RPM, which is where a truck should spend most of its time.
Last edited by mSaLL150; Jun 30, 2008 at 10:43 PM.
Senior Member
Joined: Mar 2008
Posts: 248
Likes: 0
From: Vegas baby!!!
7lug, thats an argument you will never win. Put a straight through muffler like magnaflow or dynomax on a dyno against a flowmaster, the flowmaster will lose every time. want proof? here ya go....
Now, if you are just after sound, yes flowmaster is probably the best (i think they sound amazing in the higher RPMs). But a straight through like dynomax sounds great at idle and lower RPM, which is where a truck should spend most of its time.
Now, if you are just after sound, yes flowmaster is probably the best (i think they sound amazing in the higher RPMs). But a straight through like dynomax sounds great at idle and lower RPM, which is where a truck should spend most of its time.
Technical Article Contributor
Joined: Aug 2006
Posts: 7,862
Likes: 0
From: Northern California
Again...look underneath some of the cars at ANY FFW event and you'll see quite a few "Slowmasters". That design has thousands of hours in R&D for a reason. FTR - I've never said that Maggies etc weren't any good, I've always refuted people who come on here and bash a chambered muffler and say things like "not performance oriented" etc. How can something not "performance oriented" even be considered in such a muffler shootout? There are several chambered designs in this shootout, and obviously a 370rwhp N/A Mustang isn't the same as a near stock 3v 5.4 nor will it have the same exhaust characteristics or demands. I just hate it when people blame the poor performance on a muffler rather than the poorly designed system. We can agree to disagree, I know what I've felt/seen/heard and so do you
Yes, many high performance cars use flowmasters, which i guess flow fine in higher RPMs. Lower RPMs where trucks need torque is where the straight through muffler is better performaing.
But guess what? i currently run a flowmaster on my truck.:o Why? Becuase it sounds awesome, much better toned and louder than my friends 14" magnaflow on his 04 F150.