Blocked off Side Exhausts?
12/30/12, 08:47 AM
#41
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Well Gentlemen,
I have a 2005 GT-different engine. I love the Coyote engine so that's why I want a Boss. I would actually prefer the GT but can't get the Boss engine (as modified by Ford) in that car so I'm trying to modify the Boss to fit my desires.
I have been involved with bikes for many years and have a 2012 BMW S1000RR. It weighs about 450 lbs and has 193hp at the crank, look it up. In other words weighs about one-tenth as much as a Boss with almost one-half the HP. It has a custom full Akrapovic exhaust system installed amongst other modifications. So I have some experience with exhaust systems.
I think the side pipes like the Boss's sound tube are there to appease the buyer and are not performance enhancements. The manner of the side exhausts and the tiny little hole may well create turbulence in the tubes which may hinder the extraction of exhaust gases I don't know this for a fact but I don't like the right angle turns and small diameter. Exhaust gas behaves like a liquid and even if the restrictor plates are removed not much exhaust is going to make a 90 degree turn to enter these little side pipes. They are there to make noise for the driver and if I'm that driver I would rather the exhaust continue undisturbed to the rear of the car.
For the gentlemen who was concerned that blocking off the side pipes would create too much back pressure, I offer: Back pressure is not always bad, especially at low RPM. Moreover since this engine has variable cam timing on both the intake and exhaust, I doubt back pressure or the lack thereof is an issue for it.
Curtis
I have a 2005 GT-different engine. I love the Coyote engine so that's why I want a Boss. I would actually prefer the GT but can't get the Boss engine (as modified by Ford) in that car so I'm trying to modify the Boss to fit my desires.
I have been involved with bikes for many years and have a 2012 BMW S1000RR. It weighs about 450 lbs and has 193hp at the crank, look it up. In other words weighs about one-tenth as much as a Boss with almost one-half the HP. It has a custom full Akrapovic exhaust system installed amongst other modifications. So I have some experience with exhaust systems.
I think the side pipes like the Boss's sound tube are there to appease the buyer and are not performance enhancements. The manner of the side exhausts and the tiny little hole may well create turbulence in the tubes which may hinder the extraction of exhaust gases I don't know this for a fact but I don't like the right angle turns and small diameter. Exhaust gas behaves like a liquid and even if the restrictor plates are removed not much exhaust is going to make a 90 degree turn to enter these little side pipes. They are there to make noise for the driver and if I'm that driver I would rather the exhaust continue undisturbed to the rear of the car.
For the gentlemen who was concerned that blocking off the side pipes would create too much back pressure, I offer: Back pressure is not always bad, especially at low RPM. Moreover since this engine has variable cam timing on both the intake and exhaust, I doubt back pressure or the lack thereof is an issue for it.
Curtis
12/30/12, 08:48 AM
#42
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Glenn thanks for the Sound proofing idea. I hadn't considered that and am impressed that Ford removed it if for weight reduction, no so if for sound "enhancement"
VTBoss302, Bravo and well said in my view you are spot on about the engine, exhaust (side pipes) and replacing the H-pipe (turbulence reduction which improves scavenging). In fact I almost mentioned the lack of these side pipes in the race cars, in an earlier post, but didn't want to start another "war".
06blackvertstang, After I retired I spent some years managing a Harley-Davidson dealership where I became intimately familiar with Harley owner's love of straight pipes and other "performance enhancements". I'm here to tell you loud ain't always faster. Open pipes work on dragsters, and NASCAR vehicles because they operated at WOT or near WOT all the time when in use. Our street cars (& bikes) spend very little actual time at WOT. Ergo, open exhausts or nearly so, are not necessarily better or faster, just louder. Without writing a book the subject what's
at issue here is reversion/anti-reversion of exhaust pulses and their effect on incoming fuel/air charges to the engine. With variable timed cam shafts, I'm unsure what part, if any, anti-vervision properties of the exhaust play in improving performance. Perhaps someone more knowledgeable could help all of us. But remember Loud ain't always better!!
CDynaco, I've been retired for twenty (20) years and so don't see many attorneys at stop lights or otherwise. However, I assure you if I wanted to intimidate or humble someone (including the Boss) at a stoplight or elsewhere, I would take the BIKE!!
Ace720ace, thanks for the CEL warning on the long tubes. It was a future project, if at all.
Mackds, No that's why you bought a Boss. I just feel that a little piece of American automotive history which started with Henry Ford will cease with the passing of this beautiful Coyote V-8 as modified in the Boss. The fact that it is delivered this way from the factory only adds to it's "value" to me. Remember GM still uses a push rod V-8, even in the Corvette. For me who's not getting any younger, I just want to own this engine before my time is up. But, I do not want mine to sound like a NASCAR every time I go to the grocery store, etc and all the more so because I doubt there is any performance advantage to doing so.
I'll let someone else address your calim to 1.0g corners on public roads with a live axle and street tires.
Cheers,
Curtis
VTBoss302, Bravo and well said in my view you are spot on about the engine, exhaust (side pipes) and replacing the H-pipe (turbulence reduction which improves scavenging). In fact I almost mentioned the lack of these side pipes in the race cars, in an earlier post, but didn't want to start another "war".
06blackvertstang, After I retired I spent some years managing a Harley-Davidson dealership where I became intimately familiar with Harley owner's love of straight pipes and other "performance enhancements". I'm here to tell you loud ain't always faster. Open pipes work on dragsters, and NASCAR vehicles because they operated at WOT or near WOT all the time when in use. Our street cars (& bikes) spend very little actual time at WOT. Ergo, open exhausts or nearly so, are not necessarily better or faster, just louder. Without writing a book the subject what's
at issue here is reversion/anti-reversion of exhaust pulses and their effect on incoming fuel/air charges to the engine. With variable timed cam shafts, I'm unsure what part, if any, anti-vervision properties of the exhaust play in improving performance. Perhaps someone more knowledgeable could help all of us. But remember Loud ain't always better!!
CDynaco, I've been retired for twenty (20) years and so don't see many attorneys at stop lights or otherwise. However, I assure you if I wanted to intimidate or humble someone (including the Boss) at a stoplight or elsewhere, I would take the BIKE!!
Ace720ace, thanks for the CEL warning on the long tubes. It was a future project, if at all.
Mackds, No that's why you bought a Boss. I just feel that a little piece of American automotive history which started with Henry Ford will cease with the passing of this beautiful Coyote V-8 as modified in the Boss. The fact that it is delivered this way from the factory only adds to it's "value" to me. Remember GM still uses a push rod V-8, even in the Corvette. For me who's not getting any younger, I just want to own this engine before my time is up. But, I do not want mine to sound like a NASCAR every time I go to the grocery store, etc and all the more so because I doubt there is any performance advantage to doing so.
I'll let someone else address your calim to 1.0g corners on public roads with a live axle and street tires.
Cheers,
Curtis
12/30/12, 09:01 AM
#43
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Well Bpmurr,
My full Akrapovic stainless steel system on my Bike is the same as used on the race bikes (WSBK) except theirs is titanium for weight purposes. It is not much louder than the OEM system, as many tracks have noise restrictions nowadays. It's primary goal is to improve flow by eliminating the CAT in the system and incorporating smoother mandrel bends in the headers.
Also, my bike does not have variable ratio cam shafts (like the Boss), and spends some but very little actual time at WOT. Moreover my camshafts have a lot of overlap because the engine develops about 200hp per liter of displacement and revs to 14,200 rpms ( i.e. twice the Boss), so some anti-reversion properties are required and accordingly the silencer on the race system is actually larger than the OEM silencer, to make up for the lack of the CAT. 'Nother words, sounds about the same as stock, but flow improved. Actually I have had an opportunity to hear this thing with an open header and it will drive you away...........it hurts!
Curtis
My full Akrapovic stainless steel system on my Bike is the same as used on the race bikes (WSBK) except theirs is titanium for weight purposes. It is not much louder than the OEM system, as many tracks have noise restrictions nowadays. It's primary goal is to improve flow by eliminating the CAT in the system and incorporating smoother mandrel bends in the headers.
Also, my bike does not have variable ratio cam shafts (like the Boss), and spends some but very little actual time at WOT. Moreover my camshafts have a lot of overlap because the engine develops about 200hp per liter of displacement and revs to 14,200 rpms ( i.e. twice the Boss), so some anti-reversion properties are required and accordingly the silencer on the race system is actually larger than the OEM silencer, to make up for the lack of the CAT. 'Nother words, sounds about the same as stock, but flow improved. Actually I have had an opportunity to hear this thing with an open header and it will drive you away...........it hurts!
Curtis
12/30/12, 09:10 AM
#44
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Well Bpmurr,
My full Akrapovic stainless steel system on my Bike is the same as used on the race bikes (WSBK) except theirs is titanium for weight purposes. It is not much louder than the OEM system, as many tracks have noise restrictions nowadays. It's primary goal is to improve flow by eliminating the CAT in the system and incorporating smoother mandrel bends in the headers.
Also, my bike does not have variable ratio cam shafts (like the Boss), and spends some but very little actual time at WOT. Moreover my camshafts have a lot of overlap because the engine develops about 200hp per liter of displacement and revs to 14,200 rpms ( i.e. twice the Boss), so some anti-reversion properties are required and accordingly the silencer on the race system is actually larger than the OEM silencer, to make up for the lack of the CAT. 'Nother words, sounds about the same as stock, but flow improved. Actually I have had an opportunity to hear this thing with an open header and it will drive you away...........it hurts!
Curtis
My full Akrapovic stainless steel system on my Bike is the same as used on the race bikes (WSBK) except theirs is titanium for weight purposes. It is not much louder than the OEM system, as many tracks have noise restrictions nowadays. It's primary goal is to improve flow by eliminating the CAT in the system and incorporating smoother mandrel bends in the headers.
Also, my bike does not have variable ratio cam shafts (like the Boss), and spends some but very little actual time at WOT. Moreover my camshafts have a lot of overlap because the engine develops about 200hp per liter of displacement and revs to 14,200 rpms ( i.e. twice the Boss), so some anti-reversion properties are required and accordingly the silencer on the race system is actually larger than the OEM silencer, to make up for the lack of the CAT. 'Nother words, sounds about the same as stock, but flow improved. Actually I have had an opportunity to hear this thing with an open header and it will drive you away...........it hurts!
Curtis
12/30/12, 09:32 AM
#45
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Glenn thanks for the Sound proofing idea. I hadn't considered that and am impressed that Ford removed it if for weight reduction, no so if for sound "enhancement"
VTBoss302, Bravo and well said in my view you are spot on about the engine, exhaust (side pipes) and replacing the H-pipe (turbulence reduction which improves scavenging). In fact I almost mentioned the lack of these side pipes in the race cars, in an earlier post, but didn't want to start another "war".
06blackvertstang, After I retired I spent some years managing a Harley-Davidson dealership where I became intimately familiar with Harley owner's love of straight pipes and other "performance enhancements". I'm here to tell you loud ain't always faster. Open pipes work on dragsters, and NASCAR vehicles because they operated at WOT or near WOT all the time when in use. Our street cars (& bikes) spend very little actual time at WOT. Ergo, open exhausts or nearly so, are not necessarily better or faster, just louder. Without writing a book the subject what's
at issue here is reversion/anti-reversion of exhaust pulses and their effect on incoming fuel/air charges to the engine. With variable timed cam shafts, I'm unsure what part, if any, anti-vervision properties of the exhaust play in improving performance. Perhaps someone more knowledgeable could help all of us. But remember Loud ain't always better!!
CDynaco, I've been retired for twenty (20) years and so don't see many attorneys at stop lights or otherwise. However, I assure you if I wanted to intimidate or humble someone (including the Boss) at a stoplight or elsewhere, I would take the BIKE!!
Ace720ace, thanks for the CEL warning on the long tubes. It was a future project, if at all.
Mackds, No that's why you bought a Boss. I just feel that a little piece of American automotive history which started with Henry Ford will cease with the passing of this beautiful Coyote V-8 as modified in the Boss. The fact that it is delivered this way from the factory only adds to it's "value" to me. Remember GM still uses a push rod V-8, even in the Corvette. For me who's not getting any younger, I just want to own this engine before my time is up. But, I do not want mine to sound like a NASCAR every time I go to the grocery store, etc and all the more so because I doubt there is any performance advantage to doing so.
I'll let someone else address your calim to 1.0g corners on public roads with a live axle and street tires.
Cheers,
Curtis
VTBoss302, Bravo and well said in my view you are spot on about the engine, exhaust (side pipes) and replacing the H-pipe (turbulence reduction which improves scavenging). In fact I almost mentioned the lack of these side pipes in the race cars, in an earlier post, but didn't want to start another "war".
06blackvertstang, After I retired I spent some years managing a Harley-Davidson dealership where I became intimately familiar with Harley owner's love of straight pipes and other "performance enhancements". I'm here to tell you loud ain't always faster. Open pipes work on dragsters, and NASCAR vehicles because they operated at WOT or near WOT all the time when in use. Our street cars (& bikes) spend very little actual time at WOT. Ergo, open exhausts or nearly so, are not necessarily better or faster, just louder. Without writing a book the subject what's
at issue here is reversion/anti-reversion of exhaust pulses and their effect on incoming fuel/air charges to the engine. With variable timed cam shafts, I'm unsure what part, if any, anti-vervision properties of the exhaust play in improving performance. Perhaps someone more knowledgeable could help all of us. But remember Loud ain't always better!!
CDynaco, I've been retired for twenty (20) years and so don't see many attorneys at stop lights or otherwise. However, I assure you if I wanted to intimidate or humble someone (including the Boss) at a stoplight or elsewhere, I would take the BIKE!!
Ace720ace, thanks for the CEL warning on the long tubes. It was a future project, if at all.
Mackds, No that's why you bought a Boss. I just feel that a little piece of American automotive history which started with Henry Ford will cease with the passing of this beautiful Coyote V-8 as modified in the Boss. The fact that it is delivered this way from the factory only adds to it's "value" to me. Remember GM still uses a push rod V-8, even in the Corvette. For me who's not getting any younger, I just want to own this engine before my time is up. But, I do not want mine to sound like a NASCAR every time I go to the grocery store, etc and all the more so because I doubt there is any performance advantage to doing so.
I'll let someone else address your calim to 1.0g corners on public roads with a live axle and street tires.
Cheers,
Curtis
I didn't want to make it sound like louder was faster. I understand that. Corvettes seem like some of the quietest cars on the road to me but we all know they're very good cars. I personally like louder, but hey you have the right to mod the car the way YOU want to. I never meant to impose on that. I was just trying to figure out from the beginning why you'd make it quieter. It seemed so odd with all the exhaust threads you normally see to make car louder. But hey, it's your decision! Power to you. Never meant to say you were making the wrong or uniformed decision, I simply wanted to understand your reasoning for making the boss quieter.
I'm sure you have some great stories from the Harley store too. You've probably seen a lot of great stuff.
Thanks for your patience and willingness to explain yourself - even when you don't have to.
Have fun with your boss, friend! Keep the boss pipe incase you decide to go louder though
12/30/12, 11:53 AM
#46
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Thanks, Mr. V and 06...........,
In addition to my other duties at the HD dealership, I was in charge of speed enhancements. Believe me HD's need help, 'nuf said. When first I started there I learned that I and much of the general public labored under lots of misconceptions and misinformation concerning internal combustion engines, in fact I didn't even know what a cam shaft does.......I heard of them but that was about it. The fact is that a motor is nnothing more than an air pump. So if we can help it move more air faster we have made it more efficient. The term is volumetric efficiency, for anyone who wants to learn more.
Anyway I enjoy helping folks understand and I appreciate your kind remarks.
Curtis
In addition to my other duties at the HD dealership, I was in charge of speed enhancements. Believe me HD's need help, 'nuf said. When first I started there I learned that I and much of the general public labored under lots of misconceptions and misinformation concerning internal combustion engines, in fact I didn't even know what a cam shaft does.......I heard of them but that was about it. The fact is that a motor is nnothing more than an air pump. So if we can help it move more air faster we have made it more efficient. The term is volumetric efficiency, for anyone who wants to learn more.
Anyway I enjoy helping folks understand and I appreciate your kind remarks.
Curtis
12/30/12, 03:13 PM
#47
So what you are saying here is that the changes you are going to make to your car are for the better? That would imply that Ford put in the side exhaust as no more than a gimmick and to the detriment of performance?
12/30/12, 05:57 PM
#48
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Orng32,
I personally would like the car to be quieter. So that makes my proposed changes "better" for me if it makes the cabin quieter. I merely opined, as did others, that the side pipes appeared to me to be for making noise and I was and am unsure but doubtful that they improve performance. After all one doesn't see them on race cars amongst other indications.
Moreover there's the matter of the so called "sound tube" where raw intake air is funneled into the cabin from the intake track. I am certain that the purpose of this is to produce sound in the cabin and has nothing to do with performance. In fact I'd bet this produces turbulence in the intake track, where one wants smooth laminar flow so it would detract from performance (marginally). Beyond that you may draw your own conclusions, as I have.
Cheers,
Curtis
I personally would like the car to be quieter. So that makes my proposed changes "better" for me if it makes the cabin quieter. I merely opined, as did others, that the side pipes appeared to me to be for making noise and I was and am unsure but doubtful that they improve performance. After all one doesn't see them on race cars amongst other indications.
Moreover there's the matter of the so called "sound tube" where raw intake air is funneled into the cabin from the intake track. I am certain that the purpose of this is to produce sound in the cabin and has nothing to do with performance. In fact I'd bet this produces turbulence in the intake track, where one wants smooth laminar flow so it would detract from performance (marginally). Beyond that you may draw your own conclusions, as I have.
Cheers,
Curtis
12/30/12, 07:35 PM
#50
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orng302,
The primary purpose of the side exhaust was for sound & not performance, a 'driving experience enhancement' & the fact that you 'might' gain a few HP from removing the side exhaust plates was icing in the cake.
Curtis,
If you are set against the added sound, I would also suggest you replace the H-pipe with a regular GT version. If you do plan on adding LT's down the road, the side pipes will be moot, as the increased noise generated by LT's will be much more than the little added from the side pipes.
My own opinion was the car was too quiet with the factory mufflers & side plates, but this was after driving a 06 GT with LT's, no cats & chambered mufflers.
The primary purpose of the side exhaust was for sound & not performance, a 'driving experience enhancement' & the fact that you 'might' gain a few HP from removing the side exhaust plates was icing in the cake.
Curtis,
If you are set against the added sound, I would also suggest you replace the H-pipe with a regular GT version. If you do plan on adding LT's down the road, the side pipes will be moot, as the increased noise generated by LT's will be much more than the little added from the side pipes.
My own opinion was the car was too quiet with the factory mufflers & side plates, but this was after driving a 06 GT with LT's, no cats & chambered mufflers.
12/30/12, 09:42 PM
#51
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12/30/12, 09:50 PM
#52
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Didn't they? In any case, I love it. Especially the pop and burble when downshifting.
12/30/12, 09:50 PM
#53
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AirCare84,
I guess the LT headers remove the CATS and thus the increase in noise. I agree a new H pipe would be the best solution.
FenderAddict12, yes, several people have mentioned additional sound proofing and I added that to my list. I remember my Z06 was loud, since there is no separate trunk. Mine was the coupe not the hatch (fast) back. Loud, but not like a hole in the exhaust system.
Curtis
I guess the LT headers remove the CATS and thus the increase in noise. I agree a new H pipe would be the best solution.
FenderAddict12, yes, several people have mentioned additional sound proofing and I added that to my list. I remember my Z06 was loud, since there is no separate trunk. Mine was the coupe not the hatch (fast) back. Loud, but not like a hole in the exhaust system.
Curtis
12/31/12, 04:20 PM
#54
I'm sorry but this is akin to inserting a cork into your behind because the increased pressure from a good meal causes you to flatulate with too much force. If going backwards is your kind of thing, take a gander at the following writeup. Start at the end and finish at the beginning (ignore the portion where the power gained exceeds the power lost). Blocking what little flow that actually makes it out of the side pipes should be perfect for the silent but deadly attempt.
http://www.mustang50magazine.com/tec...s/viewall.html
Curtis, the fact that you'd contemplate headers on this car makes no sense in the context of quieting the car down. And you mention being 'old' in your original post. Has your hearing somehow gotten better with age?
http://www.mustang50magazine.com/tec...s/viewall.html
Curtis, the fact that you'd contemplate headers on this car makes no sense in the context of quieting the car down. And you mention being 'old' in your original post. Has your hearing somehow gotten better with age?
Last edited by Tob*; 12/31/12 at 04:23 PM.
12/31/12, 10:23 PM
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I'm wingin it here but I remember reading about the pulses and ways to manage that for better low end. (That's why I'm sure Ford didn't just slap these side pipes on without any engineering.)
But what I really remember was back in the 70's we would ditch our stock exhaust on our 2 stroke dirt bikes for an expansion chamber that was designed to manage back pressure for more power - vs an open pipe with the baffle removed.
So these days the science is really honed no doubt.
But what I really remember was back in the 70's we would ditch our stock exhaust on our 2 stroke dirt bikes for an expansion chamber that was designed to manage back pressure for more power - vs an open pipe with the baffle removed.
So these days the science is really honed no doubt.
1/1/13, 02:00 AM
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cdynaco.
The exhaust pulses and their management are what all this exhaust talk is about my friend that, and exhaust gas scavenging.
Happy New Year,
Curtis
The exhaust pulses and their management are what all this exhaust talk is about my friend that, and exhaust gas scavenging.
Happy New Year,
Curtis
1/1/13, 09:12 AM
#58
1/1/13, 09:27 AM
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Tob,
First let me clarify. By "comment if appropriate" I meant I would read the article and respond as it relates to our conversation. I did not meant to imply that your citation of the article was in error, misplaced or misguided.
Now to the link, I am unable to get anything but a black blank page. I even went to the magazine's home page, and while I get that to display, I get blank black page(s) for everything else on the site. I noticed that one can subscribe to the magazine from the opening page, and was wondering if you were a subscriber which might account for your successful access and my failure.
Curtis
First let me clarify. By "comment if appropriate" I meant I would read the article and respond as it relates to our conversation. I did not meant to imply that your citation of the article was in error, misplaced or misguided.
Now to the link, I am unable to get anything but a black blank page. I even went to the magazine's home page, and while I get that to display, I get blank black page(s) for everything else on the site. I noticed that one can subscribe to the magazine from the opening page, and was wondering if you were a subscriber which might account for your successful access and my failure.
Curtis
1/1/13, 08:37 PM
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Looks to me that the "gain" may be due to a change in ignition timing around 5300 RPM.... Maybe knock advance or retard anomalies.
That power difference is small enough, that to compare the curves fairly, it should be accompanied by the timing curves for each run. Just sayin'
Last edited by mikerr; 1/1/13 at 08:41 PM.