UNIQUE Question for exhaust gurus..
08-14-2003, 02:54 AM
#1
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UNIQUE Question for exhaust gurus..
I'll try and avoid making this another "which aftermarket exhaust is best" thread 
. As always I'm doing more work on my 3: true duals system. I don't have an H yet.. one thing at a time. I was using 3 disk car chemistry inserts but they looked restrictive. I pulled one of the inserts out and cut the pipe down toward the end and inserted my own "homemade insert".. I know this sounds cheesey but I swear the thing sounds a lot cleaner and much less raspy/poppy than the other side that still has the cc insert in it. So, you're wondering what this thing looks like.. well I didn't take pictures but it's pretty easy to explain. I took a 1 and 3/4 diameter pipe about 1 ft long and used a flat punch (like a flat head screw driver) to creat a bunch of tabs/louvers that protrude down into the pipe (like a glass pack muffler). I then inserted this into the pipe just before it bends and dumps out toward the wheels right below the back seat buckets. I puched the tabs/perforations into it in a spiral. It's just one line of them that moves like a spiral around the pipe.
So.. before I do this to the other side.. how restrictive do you think this is? Is there any way I could test the flow? Oh.. I found this patent all over the web and modeled my insert after it.. kinda. Basically, the insert is just the "louver tube".
So.. am I being a pioneer or just plain stupid?
. As always I'm doing more work on my 3: true duals system. I don't have an H yet.. one thing at a time. I was using 3 disk car chemistry inserts but they looked restrictive. I pulled one of the inserts out and cut the pipe down toward the end and inserted my own "homemade insert".. I know this sounds cheesey but I swear the thing sounds a lot cleaner and much less raspy/poppy than the other side that still has the cc insert in it. So, you're wondering what this thing looks like.. well I didn't take pictures but it's pretty easy to explain. I took a 1 and 3/4 diameter pipe about 1 ft long and used a flat punch (like a flat head screw driver) to creat a bunch of tabs/louvers that protrude down into the pipe (like a glass pack muffler). I then inserted this into the pipe just before it bends and dumps out toward the wheels right below the back seat buckets. I puched the tabs/perforations into it in a spiral. It's just one line of them that moves like a spiral around the pipe.So.. before I do this to the other side.. how restrictive do you think this is? Is there any way I could test the flow? Oh.. I found this patent all over the web and modeled my insert after it.. kinda. Basically, the insert is just the "louver tube".
So.. am I being a pioneer or just plain stupid?
08-14-2003, 07:37 AM
#2
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Small world. I knew the inventor; he lived near here and we did some work for him quite a few years ago.
Steve is very inventive, and originally developed this muffler for motorcycles. IMO, you need all of the features of the muffler to make it work. Just punching louvers into the exhaust stream is usually bad. They impede the flow. The necessary patent language doesn't tell you much about how it really works.
This muffler is complex. The rear ring [51] has a number of holes [34] in it which help tune the system.
As I understand it, you have made a resonator. Many OEM and aftermarket systems include resonators to take out the annoying (raspy) frequencies. The less restrictive ones do not use louvers which stick down into the flow path. Dynomax makes some good ones. Basically they are "bullet" mufflers.
In answer to your question, neither pioneer nor stupid. Reinventing the wheel is always fun.
Good luck!
Steve is very inventive, and originally developed this muffler for motorcycles. IMO, you need all of the features of the muffler to make it work. Just punching louvers into the exhaust stream is usually bad. They impede the flow. The necessary patent language doesn't tell you much about how it really works.
This muffler is complex. The rear ring [51] has a number of holes [34] in it which help tune the system.
As I understand it, you have made a resonator. Many OEM and aftermarket systems include resonators to take out the annoying (raspy) frequencies. The less restrictive ones do not use louvers which stick down into the flow path. Dynomax makes some good ones. Basically they are "bullet" mufflers.
In answer to your question, neither pioneer nor stupid. Reinventing the wheel is always fun.
Good luck!
08-14-2003, 10:31 AM
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Wow.. I actually got a real guru in here I didn't think any of you guys from advanced tech even read some of the "garbage" in the LT1 tech forum 
I imagine this resonator is very different from the patent I was refering to.. if I exactly copied I probably wouldn't have come on here and said so since it is patented
Everyone always uses different words for the same thing.. I feel like by resonator you're refering to a glasspack/bullet/straight through muffler.. am I right?
If so, I felt like this is different. First, a glass pack has louvers or holes (yes, I too have read that holes are better than louvers) in the pipe. The holes allow the gas to expand into the outer canister where all the packing/sound deadening material is.. thus reducing sound. To me this is very different from whatever it is I did as I did not use any packing or sound deading material. The idea was to simply present a little friction and, moreover, to direct the gas in a spiral and thus lengthen the pipe. I didn't feel like it would be too restictive either since it is pretty far down the pipe where the gas should be cooling and contracting and thus require less area. I dunno.. I'm just experimenting. I get the impression that you think this is probably not helping flow..
No matter what, this resonator is in there now and it's gonna stay. If it's restictive then I won't do it to the other side and the H will correct for any restiction by balancing the pipes... both the cc inserts are going to be trashed also as they looked more restrictive than this resonator I made. Really the bottom line is, if I go ahead and do this to both sides will it negate the flow benefits of having a 3" true dual system? I don't want to bother with bullets as they're heavy and I have space restictions to deal with too.
so, the question is.. do this to both sides or just leave it the way is and add the H and stop there..
Thanks again for the imput guys.. I really appreciate it
I didn't think any of you guys from advanced tech even read some of the "garbage" in the LT1 tech forum I imagine this resonator is very different from the patent I was refering to.. if I exactly copied I probably wouldn't have come on here and said so since it is patented
Everyone always uses different words for the same thing.. I feel like by resonator you're refering to a glasspack/bullet/straight through muffler.. am I right?
If so, I felt like this is different. First, a glass pack has louvers or holes (yes, I too have read that holes are better than louvers) in the pipe. The holes allow the gas to expand into the outer canister where all the packing/sound deadening material is.. thus reducing sound. To me this is very different from whatever it is I did as I did not use any packing or sound deading material. The idea was to simply present a little friction and, moreover, to direct the gas in a spiral and thus lengthen the pipe. I didn't feel like it would be too restictive either since it is pretty far down the pipe where the gas should be cooling and contracting and thus require less area. I dunno.. I'm just experimenting. I get the impression that you think this is probably not helping flow..
No matter what, this resonator is in there now and it's gonna stay. If it's restictive then I won't do it to the other side and the H will correct for any restiction by balancing the pipes... both the cc inserts are going to be trashed also as they looked more restrictive than this resonator I made. Really the bottom line is, if I go ahead and do this to both sides will it negate the flow benefits of having a 3" true dual system? I don't want to bother with bullets as they're heavy and I have space restictions to deal with too.
so, the question is.. do this to both sides or just leave it the way is and add the H and stop there..
Thanks again for the imput guys.. I really appreciate it
Last edited by Lost; 08-14-2003 at 11:06 AM.
08-14-2003, 07:07 PM
#5
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Originally posted by Lost
Everyone always uses different words for the same thing.. I feel like by resonator you're refering to a glasspack/bullet/straight through muffler.. am I right?
Not necessarily. A resonator can be a perforated core with an open can around it if it is tuned properly.
I dunno.. I'm just experimenting. I get the impression that you think this is probably not helping flow..
Really the bottom line is, if I go ahead and do this to both sides will it negate the flow benefits of having a 3" true dual system? I don't want to bother with bullets as they're heavy and I have space restictions to deal with too.
so, the question is.. do this to both sides or just leave it the way is and add the H and stop there.
IMO, yes, your are hurting the flow, and the H isn't going to help much. Crossovers are more for pressure balancing than tuning.
Now if you want to get creative, look at Corsa's Reflective Sound Cancellation methods:
http://www.corsaperf.com/arsctech.htm
Basically what this involves is adding a closed-end tube to the pipe at almost any angle and selecting the length of this tuning pipe so that the sound waves of a certain frequency cancel each other out when they rejoin the pipe. They do it inside the muffler on the standard system, but look at the titanium street system:
http://www.corsaperf.com/c5titanium.htm
See how there are two tubes at right angles leading into a "muffler"? Each is tuned to cancel a certain frequency. They also use a forward mounted resonator for other frequencies.
You could experiment by welding in a tuning pipe to a mufflerless 3 inch system, and making a sliding plug which you could move to tune out a specific frequency. If you used 2 or 3 tuning pipes you could tailor the sound to about whatever you want. The tuning pipes can be smaller in dia. I'd probably try 2-1/4 or 2-1/2 inch.
An GM engineer (Tom Cassel) did exactly this about 1965. I drove some of the cars. Virtually no exhaust back pressure from this system. True, it has to be specific for each exhaust configuration, but that's not much of a problem. You can bend the tuning pipes (after you get the length right and weld on a cap) to make them fit your chassis.
The first use of this was on the tailpipes of some 70's Pontiacs in place of a resonator. They even used crimped ends on the pipes.
BTW, my Vette has a Corsa touring system. I love the sound and NO in car resonance at any cruise, and just a nasty snarl at WOT. I don' know for sure, but I wouldn't be surprised if the Cadillac CTSV with it's 400 hp LS6 engine, due out in a few months, has this technology exhaust. The WOT high rpm sound has been described as a "refined shreik".
IMO, this is DIY technology which is high flow, any sound you want, lightweight, and packages well. Oh, BTW, keep the tuning pipe slightly above level with the exhaust pipe so you don't trap water and rot it out.
That's you homework assignment. Go to it.
Everyone always uses different words for the same thing.. I feel like by resonator you're refering to a glasspack/bullet/straight through muffler.. am I right?
Not necessarily. A resonator can be a perforated core with an open can around it if it is tuned properly.
I dunno.. I'm just experimenting. I get the impression that you think this is probably not helping flow..
Really the bottom line is, if I go ahead and do this to both sides will it negate the flow benefits of having a 3" true dual system? I don't want to bother with bullets as they're heavy and I have space restictions to deal with too.
so, the question is.. do this to both sides or just leave it the way is and add the H and stop there.
IMO, yes, your are hurting the flow, and the H isn't going to help much. Crossovers are more for pressure balancing than tuning.
Now if you want to get creative, look at Corsa's Reflective Sound Cancellation methods:
http://www.corsaperf.com/arsctech.htm
Basically what this involves is adding a closed-end tube to the pipe at almost any angle and selecting the length of this tuning pipe so that the sound waves of a certain frequency cancel each other out when they rejoin the pipe. They do it inside the muffler on the standard system, but look at the titanium street system:
http://www.corsaperf.com/c5titanium.htm
See how there are two tubes at right angles leading into a "muffler"? Each is tuned to cancel a certain frequency. They also use a forward mounted resonator for other frequencies.
You could experiment by welding in a tuning pipe to a mufflerless 3 inch system, and making a sliding plug which you could move to tune out a specific frequency. If you used 2 or 3 tuning pipes you could tailor the sound to about whatever you want. The tuning pipes can be smaller in dia. I'd probably try 2-1/4 or 2-1/2 inch.
An GM engineer (Tom Cassel) did exactly this about 1965. I drove some of the cars. Virtually no exhaust back pressure from this system. True, it has to be specific for each exhaust configuration, but that's not much of a problem. You can bend the tuning pipes (after you get the length right and weld on a cap) to make them fit your chassis.
The first use of this was on the tailpipes of some 70's Pontiacs in place of a resonator. They even used crimped ends on the pipes.
BTW, my Vette has a Corsa touring system. I love the sound and NO in car resonance at any cruise, and just a nasty snarl at WOT. I don' know for sure, but I wouldn't be surprised if the Cadillac CTSV with it's 400 hp LS6 engine, due out in a few months, has this technology exhaust. The WOT high rpm sound has been described as a "refined shreik".
IMO, this is DIY technology which is high flow, any sound you want, lightweight, and packages well. Oh, BTW, keep the tuning pipe slightly above level with the exhaust pipe so you don't trap water and rot it out.
That's you homework assignment. Go to it.
08-14-2003, 10:49 PM
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interesting.. so you think the H doesn't help much? I figured the pressure would equalize... if one side if freer flowing than the other it seems that more gas would move to the more open side.. that's just intuition.. I've got no real science to back that up
As for the tuning pipes.. that's real interesting. Simple it seems. You're saying I need to take two or so 2.5 inch pipes and weld them perpendicular to the 3 inch exhaust pipe. Then put a plug in and adj the plug for a desirable sound.. right? I just want to make sure I understand this. How important is it that these pipes be perpendicular to the exhaust pipe? How long do they need to be to give me some tuning adjustability? 6 inches 10 inches? The only place they'd fit is up just after the collectors. Should they be closer to the outlet or to the collector or does it even matter? Any idea how you could rig up a sliding plug that would seal? or does the plug have to seal that well? I could adj the plug and seal the pipe with a cap on the end.. would that work?
Neat idea.. I'll see if I can play around with it..
As for the tuning pipes.. that's real interesting. Simple it seems. You're saying I need to take two or so 2.5 inch pipes and weld them perpendicular to the 3 inch exhaust pipe. Then put a plug in and adj the plug for a desirable sound.. right? I just want to make sure I understand this. How important is it that these pipes be perpendicular to the exhaust pipe? How long do they need to be to give me some tuning adjustability? 6 inches 10 inches? The only place they'd fit is up just after the collectors. Should they be closer to the outlet or to the collector or does it even matter? Any idea how you could rig up a sliding plug that would seal? or does the plug have to seal that well? I could adj the plug and seal the pipe with a cap on the end.. would that work?
Neat idea.. I'll see if I can play around with it..
08-15-2003, 03:59 AM
#7
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Just because something is patented does not mean you can,t build one and use it, now if you mass produced it and sold them then you could get in a heap of trouble.
As far as the design goes it looks alot like my Lowbaks except they have a resonator in the middle surrounded by a metal spiral, if you can visualize that.
As far as the design goes it looks alot like my Lowbaks except they have a resonator in the middle surrounded by a metal spiral, if you can visualize that.
08-15-2003, 07:13 AM
#8
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Originally posted by Lost
interesting.. so you think the H doesn't help much? I figured the pressure would equalize... if one side if freer flowing than the other it seems that more gas would move to the more open side.. that's just intuition.. I've got no real science to back that up
Sure, some of the gas will bypass the restriction thru the H, but the total system will be down on flow, and engine will suffer.
As for the tuning pipes.. that's real interesting. Simple it seems. You're saying I need to take two or so 2.5 inch pipes and weld them perpendicular to the 3 inch exhaust pipe. Then put a plug in and adj the plug for a desirable sound.. right? I just want to make sure I understand this. How important is it that these pipes be perpendicular to the exhaust pipe? How long do they need to be to give me some tuning adjustability? 6 inches 10 inches? The only place they'd fit is up just after the collectors. Should they be closer to the outlet or to the collector or does it even matter? Any idea how you could rig up a sliding plug that would seal? or does the plug have to seal that well? I could adj the plug and seal the pipe with a cap on the end.. would that work?
Neat idea.. I'll see if I can play around with it..
Not necessarily perpendicular, but that's easier to weld. They can be almost any place in the system. If you could find a node, or high pressure point at an rpm you are tuning, putting the pipe there would probably be best. However, Corsa tunes from one spot where the pipe enters the muffler.
Length depends on the frequency your are tuning out. Anywhere from maybe 10 inches to a couple of feet. Once you determine the correct length, the tuning pipe can wrap back along the exhaust pipe, or run at any angle to it. It's not a flow thing, just a closed end tuning chamber. You could probably get away with 2 inch tuning tubes. It would be easier. Crush bends should no be a problem. Engine block freeze plugs make a nice cap if you find some the right size.
Try a cork wrapped in a fiece of fibreglass cloth for your adjustable plug. Stick it on the end of a threaded rod to use as your handle. If you did this on a hoist, the pipes could hang down while you were "tuning". Maybe you could weld little stubs on the exhaust pipes, slip over your test tubes, and when the lengths have all been detemined, bend up tubes that would fit the chassis and weld or clamp them onto the stubs. Remember you need to adjust all 3 (or so) with the engine running at different speeds to get the sound and resonance you want. People will think you are a nutcase while you are doing this, by the way.
interesting.. so you think the H doesn't help much? I figured the pressure would equalize... if one side if freer flowing than the other it seems that more gas would move to the more open side.. that's just intuition.. I've got no real science to back that up
Sure, some of the gas will bypass the restriction thru the H, but the total system will be down on flow, and engine will suffer.
As for the tuning pipes.. that's real interesting. Simple it seems. You're saying I need to take two or so 2.5 inch pipes and weld them perpendicular to the 3 inch exhaust pipe. Then put a plug in and adj the plug for a desirable sound.. right? I just want to make sure I understand this. How important is it that these pipes be perpendicular to the exhaust pipe? How long do they need to be to give me some tuning adjustability? 6 inches 10 inches? The only place they'd fit is up just after the collectors. Should they be closer to the outlet or to the collector or does it even matter? Any idea how you could rig up a sliding plug that would seal? or does the plug have to seal that well? I could adj the plug and seal the pipe with a cap on the end.. would that work?
Neat idea.. I'll see if I can play around with it..
Not necessarily perpendicular, but that's easier to weld. They can be almost any place in the system. If you could find a node, or high pressure point at an rpm you are tuning, putting the pipe there would probably be best. However, Corsa tunes from one spot where the pipe enters the muffler.
Length depends on the frequency your are tuning out. Anywhere from maybe 10 inches to a couple of feet. Once you determine the correct length, the tuning pipe can wrap back along the exhaust pipe, or run at any angle to it. It's not a flow thing, just a closed end tuning chamber. You could probably get away with 2 inch tuning tubes. It would be easier. Crush bends should no be a problem. Engine block freeze plugs make a nice cap if you find some the right size.
Try a cork wrapped in a fiece of fibreglass cloth for your adjustable plug. Stick it on the end of a threaded rod to use as your handle. If you did this on a hoist, the pipes could hang down while you were "tuning". Maybe you could weld little stubs on the exhaust pipes, slip over your test tubes, and when the lengths have all been detemined, bend up tubes that would fit the chassis and weld or clamp them onto the stubs. Remember you need to adjust all 3 (or so) with the engine running at different speeds to get the sound and resonance you want. People will think you are a nutcase while you are doing this, by the way.
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