Motordyne Dual Shockwave w/Ti Tips Pics/Soundclips
12-15-2009, 02:18 PM
#661
No way to fit the stock system to my true dual setup at the moment...
Tom (thom0001) got to 900+ whp with the stock muffler modified to mate with a 4" pipe over to a huge Y pipe and I think 3" downpipes. He said his car sounds like stock around town. I have 3.5" downpipes, constricting to 3", then dropping to 2.5" for the MD XYZ pipe (pending release of a 3" version), and then going back to 3" true dual (shockwave TDX).
I like the Motordyne concept of interchangeable components and I want to be able to run straight through, loud for certain events, but switch back to quiet for daily driving. I also want to be able to run cats easily vs test pipes. I actually had my huge 3.5" test pipes broken into 2 pieces with v-bands inserted so that I could swap the lower portion out for sections with cats. Tony may also have a solution for cats in the future for the TDX.
I've got faith in Tony's ability to deliver and I'd rather support the one company that does this kind of R&D rather than trying to go it alone. And of course, Tony is the rocket scientist, not me!
If he chooses to not pursue this (wouldn't blame him as I don't know how large this market is, but right now he's the only one that would have a quiet 3" true dual/performance solution for the Z/G), then I will consider other options including reworking the stock muffer to fit or buying a large flowmaster and having a custom rear muffler mated to the MD TDX.
Tom (thom0001) got to 900+ whp with the stock muffler modified to mate with a 4" pipe over to a huge Y pipe and I think 3" downpipes. He said his car sounds like stock around town. I have 3.5" downpipes, constricting to 3", then dropping to 2.5" for the MD XYZ pipe (pending release of a 3" version), and then going back to 3" true dual (shockwave TDX).
I like the Motordyne concept of interchangeable components and I want to be able to run straight through, loud for certain events, but switch back to quiet for daily driving. I also want to be able to run cats easily vs test pipes. I actually had my huge 3.5" test pipes broken into 2 pieces with v-bands inserted so that I could swap the lower portion out for sections with cats. Tony may also have a solution for cats in the future for the TDX.
I've got faith in Tony's ability to deliver and I'd rather support the one company that does this kind of R&D rather than trying to go it alone. And of course, Tony is the rocket scientist, not me!
If he chooses to not pursue this (wouldn't blame him as I don't know how large this market is, but right now he's the only one that would have a quiet 3" true dual/performance solution for the Z/G), then I will consider other options including reworking the stock muffer to fit or buying a large flowmaster and having a custom rear muffler mated to the MD TDX.
Last edited by rcdash; 12-15-2009 at 02:38 PM.
12-15-2009, 02:44 PM
#662
Even if you only bolt up the stock exhaust portion that is after the XYZ? It should be a direct fit I think.
I agree with you that the interchangeability is great feature. This is one of the reason that made me get the MD. I actually have the non TDX version of the shockwave. If I remember correctly Tony said it isn't as lound and drone prone. BTW, I'm 6MT and have the drone at 2500rpm. Is there a logical explanation/theory why a 5AT would cause this as oppose to a 6MT? When you say he might have a solution for the cats in the future do you mean an additional cat on top of the one that fits after the XYZ?
Tony, thanks for listening to the complaints and doing something about it.
I agree with you that the interchangeability is great feature. This is one of the reason that made me get the MD. I actually have the non TDX version of the shockwave. If I remember correctly Tony said it isn't as lound and drone prone. BTW, I'm 6MT and have the drone at 2500rpm. Is there a logical explanation/theory why a 5AT would cause this as oppose to a 6MT? When you say he might have a solution for the cats in the future do you mean an additional cat on top of the one that fits after the XYZ?
Tony, thanks for listening to the complaints and doing something about it.
12-15-2009, 04:23 PM
#663
Even if you only bolt up the stock exhaust portion that is after the XYZ? It should be a direct fit I think.
I agree with you that the interchangeability is great feature. This is one of the reason that made me get the MD. I actually have the non TDX version of the shockwave. If I remember correctly Tony said it isn't as lound and drone prone. BTW, I'm 6MT and have the drone at 2500rpm. Is there a logical explanation/theory why a 5AT would cause this as oppose to a 6MT? When you say he might have a solution for the cats in the future do you mean an additional cat on top of the one that fits after the XYZ?
Tony, thanks for listening to the complaints and doing something about it.
I agree with you that the interchangeability is great feature. This is one of the reason that made me get the MD. I actually have the non TDX version of the shockwave. If I remember correctly Tony said it isn't as lound and drone prone. BTW, I'm 6MT and have the drone at 2500rpm. Is there a logical explanation/theory why a 5AT would cause this as oppose to a 6MT? When you say he might have a solution for the cats in the future do you mean an additional cat on top of the one that fits after the XYZ?
Tony, thanks for listening to the complaints and doing something about it.
12-15-2009, 04:54 PM
#664
^I know, just wondering why you said that your stock exhaust will no longer fit. The IN to either shockwave models are identical and the problem seems to exists on both but more so on the TDX version.
Not saying that you should, but it definitely would be interesting if you mate up the XYZ with the stock exhaust and see how that compares to all of the MD exhausts. It's not exactly a full on stock exhaust but it will still give a better perspective for those who do not own a shockwave yet. Unfortunately there is no personal benefit for you to do so. Anyways, thanks again for doing this.
Not saying that you should, but it definitely would be interesting if you mate up the XYZ with the stock exhaust and see how that compares to all of the MD exhausts. It's not exactly a full on stock exhaust but it will still give a better perspective for those who do not own a shockwave yet. Unfortunately there is no personal benefit for you to do so. Anyways, thanks again for doing this.
12-15-2009, 07:22 PM
#665
^I know, just wondering why you said that your stock exhaust will no longer fit. The IN to either shockwave models are identical and the problem seems to exists on both but more so on the TDX version.
Not saying that you should, but it definitely would be interesting if you mate up the XYZ with the stock exhaust and see how that compares to all of the MD exhausts. It's not exactly a full on stock exhaust but it will still give a better perspective for those who do not own a shockwave yet. Unfortunately there is no personal benefit for you to do so. Anyways, thanks again for doing this.
Not saying that you should, but it definitely would be interesting if you mate up the XYZ with the stock exhaust and see how that compares to all of the MD exhausts. It's not exactly a full on stock exhaust but it will still give a better perspective for those who do not own a shockwave yet. Unfortunately there is no personal benefit for you to do so. Anyways, thanks again for doing this.
On another note, the temp here jumped 20 degrees since yesterday to a toasty 65 F. This exhaust is definitely starting to mellow out, either because of the temperature or break-in or both. The drone is still there at 2k but it is not bad at all. This is behaving exactly as I remember the Fast Intentions exhaust behaving, but this is a tad bit quieter even. God it sounds good with the windows down. (I know, I know, vids coming!)
This is much milder than the shockwave TDX at high rpms - sporty but very, very civil. Deep and mean at low rpms with a quiet rumble at higher rpms. I think I could live with this. I had a lot of fun driving this car this evening in the warm weather.
I'd prefer the drone to be gone completely at 2k rpms. Let's see how the 1/4 wavelength resonators perform under 3k. Maybe I can get the two combined! 
I'm liking this muffler more every time I drive out. Should I keep driving it and see how mellow it gets or just take some recordings and move on? Unless I hear objections, I'm taking my recordings tomorrow night and switching to the side resonators.
Last edited by rcdash; 12-15-2009 at 08:08 PM.
12-15-2009, 07:46 PM
#666
Oh I see why it is diff in the TDX. The extension comes after the muffler. Tony sells a pipe adapter that will allow this mating that I am talking about. Sorry for the confusion, didn't notice that slight difference. I wasn't arguing which is better for your car, just pointing out that there has been a lot of comparison to the stock setup sound levels.
Good to hear that it is quieting down. And that you are liking it.
Good to hear that it is quieting down. And that you are liking it.
12-15-2009, 08:09 PM
#667
I'm glad you got post #666. I was trying to avoid it. 
It's funny how the warmer weather had such an impact. I can hear my recirc valve again! I can hear my engine! I don't have to turn the radio up! I can, unfortunately, also hear my R888 tires whine really clearly on the highway!
I think for a really good comparison, the sounds clips and rta snapshots are all going to have to be done on the same day after all have broken in, one right after another... jeez - that might be too hard to make happen. The weather right now is so unpredictable and I have a day job! I'll just do the best I can to get them all tested by this Sat regardless of weather and temps as I'm going out of the country for the holidays for a few days.
Tony, I'm going to want another pair of tips for the set I keep. I have the titanium single wall, so I was thinking about the polished dual wall as the alternate. I found this on the website - looks great:
3" inlet - that's what I want I think.
I didn't see the polished non-titanium for comparison. Is that an option? If not, I'll just place my order via your site for the above part (probably will pick this part anyway, looks really good!). Thanks!
It's funny how the warmer weather had such an impact. I can hear my recirc valve again! I can hear my engine! I don't have to turn the radio up! I can, unfortunately, also hear my R888 tires whine really clearly on the highway!
I think for a really good comparison, the sounds clips and rta snapshots are all going to have to be done on the same day after all have broken in, one right after another... jeez - that might be too hard to make happen. The weather right now is so unpredictable and I have a day job! I'll just do the best I can to get them all tested by this Sat regardless of weather and temps as I'm going out of the country for the holidays for a few days.
Tony, I'm going to want another pair of tips for the set I keep. I have the titanium single wall, so I was thinking about the polished dual wall as the alternate. I found this on the website - looks great:
3" inlet - that's what I want I think.I didn't see the polished non-titanium for comparison. Is that an option? If not, I'll just place my order via your site for the above part (probably will pick this part anyway, looks really good!). Thanks!
Last edited by rcdash; 12-15-2009 at 08:25 PM.
12-16-2009, 09:47 PM
#668
UPDATE: RTA first (video encoding, have patience!)
This is the large VQ muffler RTA (green is idle and purple is at 1800 rpms). The drone is present between 1600-1900 rpms primarily and this results in a spike between 80 to 100 Hz. At idle (most prominently) there is also a quieter drone around 50-60 Hz. These spikes were present on the shockwave TDX as well but were of greater magnitude (see 2nd pic).
This next one compares the Shockwave TDX in green to the VQ muffler in blue (both at 2k rpms). There is a definite noise reduction in real life but i'm not sure if the magnitude of the reduction is accurately reflected in these graphs. I don't understand the 6 db shift of the quieter exhaust in the high frequecy part of the spectrum!
These were two different samplings on different days combined onto a single graph. When I swap mufflers again, I'll try to update RTA data to see if there's any difference day to day.
Video should be ready on youtube soon - will post link in am...
This is the large VQ muffler RTA (green is idle and purple is at 1800 rpms). The drone is present between 1600-1900 rpms primarily and this results in a spike between 80 to 100 Hz. At idle (most prominently) there is also a quieter drone around 50-60 Hz. These spikes were present on the shockwave TDX as well but were of greater magnitude (see 2nd pic).
This next one compares the Shockwave TDX in green to the VQ muffler in blue (both at 2k rpms). There is a definite noise reduction in real life but i'm not sure if the magnitude of the reduction is accurately reflected in these graphs. I don't understand the 6 db shift of the quieter exhaust in the high frequecy part of the spectrum!
These were two different samplings on different days combined onto a single graph. When I swap mufflers again, I'll try to update RTA data to see if there's any difference day to day.
Video should be ready on youtube soon - will post link in am...
Last edited by rcdash; 12-17-2009 at 11:53 AM.
12-17-2009, 05:01 AM
#670
I'm wondering is there could be a measurement offset in the second set. (blue)
It looks like it has ~6db step shift shown above 2.5K Hz. Is the whole blue plot somehow biased up ~6 db?
I would assume any audio captured above 2.5K Hz is just background or measurement white noise.
If time allows, try a control group on the measurement error just to see if there is any funkyness in the audio measurement process.
Funkyness - that's a technical term.
It looks like it has ~6db step shift shown above 2.5K Hz. Is the whole blue plot somehow biased up ~6 db?
I would assume any audio captured above 2.5K Hz is just background or measurement white noise.
If time allows, try a control group on the measurement error just to see if there is any funkyness in the audio measurement process.
Funkyness - that's a technical term.
12-17-2009, 05:15 AM
#672
YOu know Raj, the simple solution woulda just been the stock exhaust (or even the Intense knockoff with 3" piping) with a boost activated cutout from sound performance.
completely stock, drone free until that 4-450 hp point where you open the valve.
completely stock, drone free until that 4-450 hp point where you open the valve.
12-17-2009, 06:26 AM
#673
There will be nothing like having a true dual 3" exhaust with a nicely designed muffler on there. No valves, nothing to fail, like it was designed from the factory to be a turbo'd supercar.
12-17-2009, 06:45 AM
#674
I'm wondering is there could be a measurement offset in the second set. (blue)
It looks like it has ~6db step shift shown above 2.5K Hz. Is the whole blue plot somehow biased up ~6 db?
I would assume any audio captured above 2.5K Hz is just background or measurement white noise.
If time allows, try a control group on the measurement error just to see if there is any funkyness in the audio measurement process.
Funkyness - that's a technical term.
It looks like it has ~6db step shift shown above 2.5K Hz. Is the whole blue plot somehow biased up ~6 db?
I would assume any audio captured above 2.5K Hz is just background or measurement white noise.
If time allows, try a control group on the measurement error just to see if there is any funkyness in the audio measurement process.
Funkyness - that's a technical term.
I cannot find the video I started the upload for last night onto youtube - not on my channel.
Crap - forgot to check it this am before leaving for work. Got to see if the wifey can help me - hang on...
Last edited by rcdash; 12-17-2009 at 06:48 AM.
12-17-2009, 11:51 AM
#675
This is a great thread. I'm surprised that there is not more of measured difference in the TDX Shockwave vs the VQ TDX. With the Shockwave Single vs the VQ, I found there was a HUGE difference (at least to my ear) and the VQ completely eliminated any drone. There was a lot of drone with the Single Shockwave around 2200rpm.
However, if memory serves, Db is a logarithmic scale so that may account for what looks like a small difference on the graph being quite a large difference in actual sound level?
However, if memory serves, Db is a logarithmic scale so that may account for what looks like a small difference on the graph being quite a large difference in actual sound level?
12-17-2009, 06:07 PM
#676
visual? you've actually been to a inspection that did a visual?
I've been thinking to do a dual 3" y into a 3.5"-4" main to the stock muffler. RJ muffler on Capital has that mandrel bender and could fab that up pretty easily.
too bad you cant get ahold of that GTM exhaust with those dual magnaflows. I talked to a shop about replicating that, but it wasnt worth their time....
turn downs/open dump/fireballs for me for the immediate future. I'l prolly give you a headache in your car on the cruise to Zdayz
I've been thinking to do a dual 3" y into a 3.5"-4" main to the stock muffler. RJ muffler on Capital has that mandrel bender and could fab that up pretty easily.
too bad you cant get ahold of that GTM exhaust with those dual magnaflows. I talked to a shop about replicating that, but it wasnt worth their time....
turn downs/open dump/fireballs for me for the immediate future. I'l prolly give you a headache in your car on the cruise to Zdayz
I did consider that but even that is not perfect. The SP valve was not out at the time. ATP turbo had one, but was perpetually back ordered. The valves that were available apparently ended up leaking. Having a valve there will fail a visual inspection here in NC. Lots of little issues.
There will be nothing like having a true dual 3" exhaust with a nicely designed muffler on there. No valves, nothing to fail, like it was designed from the factory to be a turbo'd supercar.
There will be nothing like having a true dual 3" exhaust with a nicely designed muffler on there. No valves, nothing to fail, like it was designed from the factory to be a turbo'd supercar.
12-17-2009, 06:11 PM
#677
The VQ TDX is definitely quieter and the dB scale is logarithmic. I think the VQ TDX mufflers are smaller than the single VQ muffler. I did a quick query as I always believed that a 10 dB increase meant a doubling of perceived loudness, but I found this (Tony can you comment?):
Doubling of the volume (loudness) should be felt by a level difference of 10 dB.
Doubling the sound pressure (voltage) level corresponds to a measured level change of 6 dB.
Doubling of acoustic power (sound intensity) level corresponds to a measured level change of 3 dB. (not sure what this means)
Here is the video that failed to upload last night... you MUST have a subwoofer or speakers that can produce 50 Hz sound or you will be missing a lot of the "loudness" that is left with this VQ TDX design.
<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/-Zvm1lO6Hyc&hl=en_US&fs=1&"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/-Zvm1lO6Hyc&hl=en_US&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>
(I apologize in advance for the shaky camera mount - didn't realize the slat of hardwood would bounce so much - will reinforce somehow. Also the touchscreen display with the RTA didn't show up on camera, but I posted the relevant captures above. Also no WOT runs in the cold temps - sorry.)
Doubling of the volume (loudness) should be felt by a level difference of 10 dB.
Doubling the sound pressure (voltage) level corresponds to a measured level change of 6 dB.
Doubling of acoustic power (sound intensity) level corresponds to a measured level change of 3 dB. (not sure what this means)
Here is the video that failed to upload last night... you MUST have a subwoofer or speakers that can produce 50 Hz sound or you will be missing a lot of the "loudness" that is left with this VQ TDX design.
<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/-Zvm1lO6Hyc&hl=en_US&fs=1&"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/-Zvm1lO6Hyc&hl=en_US&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>
(I apologize in advance for the shaky camera mount - didn't realize the slat of hardwood would bounce so much - will reinforce somehow. Also the touchscreen display with the RTA didn't show up on camera
, but I posted the relevant captures above. Also no WOT runs in the cold temps - sorry.)
Last edited by rcdash; 12-17-2009 at 06:33 PM.
12-17-2009, 06:15 PM
#678
visual? you've actually been to a inspection that did a visual?
I've been thinking to do a dual 3" y into a 3.5"-4" main to the stock muffler. RJ muffler on Capital has that mandrel bender and could fab that up pretty easily.
too bad you cant get ahold of that GTM exhaust with those dual magnaflows. I talked to a shop about replicating that, but it wasnt worth their time....
turn downs/open dump/fireballs for me for the immediate future. I'l prolly give you a headache in your car on the cruise to Zdayz
I've been thinking to do a dual 3" y into a 3.5"-4" main to the stock muffler. RJ muffler on Capital has that mandrel bender and could fab that up pretty easily.
too bad you cant get ahold of that GTM exhaust with those dual magnaflows. I talked to a shop about replicating that, but it wasnt worth their time....
turn downs/open dump/fireballs for me for the immediate future. I'l prolly give you a headache in your car on the cruise to Zdayz
Yes Michael Jordan Nissan will do a visual.
I actually had cats and they gave me a hard time. In fact, every tech was under my car pointing out things I didn't even have, like nitrous solenoids and what not. Jeez.
12-17-2009, 06:25 PM
#679
Doubling of the volume (loudness) should be felt by a level difference of 10 dB.
Doubling the sound pressure (voltage) level corresponds to a measured level change of 6 dB.
Doubling of acoustic power (sound intensity) level corresponds to a measured level change of 3 dB. (not sure what this means)
Doubling the sound pressure (voltage) level corresponds to a measured level change of 6 dB.
Doubling of acoustic power (sound intensity) level corresponds to a measured level change of 3 dB. (not sure what this means)
EDIT: Great job on the data logging and analysis.
More importantly, how do those mufflers work for you on a completely subjective level?
Last edited by Hydrazine; 12-17-2009 at 06:37 PM.
12-17-2009, 09:03 PM
#680
Okay, 20 mins later and I got the v2 shockwave TDX on there! This thing is amazing. It is very quiet under 3k rpms. Compare the large dual VQ TDX in blue (around 2k rpms) to the side resonator TDX (shockwave TDX v2 around 1800 rpms) in pink (note the 50 Hz peak is gone):
Here is the shockwave TDX v2 at idle (green) , 1500-1600 rpms (orange, a tiny bit of drone here), 1800 rpms (pink), 2500 rpms (yellow):
The important thing here is that the 5AT never spends much time at 1500-1600 rpms, which is where the residual drone is with these side canisters. Also most importantly, the 50 Hz peak is gone. This exhaust sounds "clean" with much less rumbling drone than either the shockwave tdx or the large muffler dual vq tdx. The 1800 rpm drone (of the large muffler VQ TDX) AND the 2500 rpm drone (of the shockwave TDX) are both gone!
This is very, very nice. You know Tony, I've got to ask you if there are any technical barriers in integrating these two designs together? Is it possible?
I will try to get some video clips though it's supposed to flurry here in NC the next 2 days and then I leave out of town for a few days. I will try though.
This thing is amazing. It is very quiet under 3k rpms. Compare the large dual VQ TDX in blue (around 2k rpms) to the side resonator TDX (shockwave TDX v2 around 1800 rpms) in pink (note the 50 Hz peak is gone):Here is the shockwave TDX v2 at idle (green) , 1500-1600 rpms (orange, a tiny bit of drone here), 1800 rpms (pink), 2500 rpms (yellow):
The important thing here is that the 5AT never spends much time at 1500-1600 rpms, which is where the residual drone is with these side canisters. Also most importantly, the 50 Hz peak is gone. This exhaust sounds "clean" with much less rumbling drone than either the shockwave tdx or the large muffler dual vq tdx. The 1800 rpm drone (of the large muffler VQ TDX) AND the 2500 rpm drone (of the shockwave TDX) are both gone!
This is very, very nice.
You know Tony, I've got to ask you if there are any technical barriers in integrating these two designs together? Is it possible?I will try to get some video clips though it's supposed to flurry here in NC the next 2 days and then I leave out of town for a few days.
I will try though.
Last edited by rcdash; 12-17-2009 at 09:09 PM.