Motordyne Dual Shockwave w/Ti Tips Pics/Soundclips
11-30-2009, 06:55 PM
#642
This is looking great so far Raj!
Maybe one thing you can do is take a snap shot @ ~2200 RPM or the subjective point at which the greatest drone occurs with the regular Shockwave tubes. Then do the same thing with the Shockwave2 at the same RPM and same throttle position. This way the RTA can give an objective measure of what is subjectively so important.
Those two data points will be the two most important points out of the whole data set.
It would also be better to measure from the driver seat. Measuring from the trunk is good for eliminating the engine induction sound but there will be a vastly different exhaust frequency response inside the trunk area.
When I was a sound technician at Hollywood Sound Labs back in the 90's I did a lot of frequency response measurements and tuning on car audio systems for sound offs. Frequency response varied greatly with position inside the cabin. Nulls, nodes and standing waves change a lot with position. Bass frequencies too.
Windows up Vs windows down. Seat level Vs ear level. Steering wheel or against the front windshield. There can be large swings in frequency response.
If possible, try to put the mic within a few inches of your ear when you do the test. That way you and the mic are measuring/hearing the same sound when you hit the capture button.
And thank you for taking the time to do this! Its work doing testing and reporting like this.
Maybe one thing you can do is take a snap shot @ ~2200 RPM or the subjective point at which the greatest drone occurs with the regular Shockwave tubes. Then do the same thing with the Shockwave2 at the same RPM and same throttle position. This way the RTA can give an objective measure of what is subjectively so important.
Those two data points will be the two most important points out of the whole data set.
It would also be better to measure from the driver seat. Measuring from the trunk is good for eliminating the engine induction sound but there will be a vastly different exhaust frequency response inside the trunk area.
When I was a sound technician at Hollywood Sound Labs back in the 90's I did a lot of frequency response measurements and tuning on car audio systems for sound offs. Frequency response varied greatly with position inside the cabin. Nulls, nodes and standing waves change a lot with position. Bass frequencies too.
Windows up Vs windows down. Seat level Vs ear level. Steering wheel or against the front windshield. There can be large swings in frequency response.
If possible, try to put the mic within a few inches of your ear when you do the test. That way you and the mic are measuring/hearing the same sound when you hit the capture button.
And thank you for taking the time to do this! Its work doing testing and reporting like this.
I'm dying to get rid of exhaust drone and try out some of these shiny new toys!!! I cannot wait to find out which design is the quietest. Hopefully weather will improve as it was raining miserably today, which creates all sorts of different road noises to contaminate the testing. I will try to get all the shockwave v1 TDX baseline testing and sound recordings completed and posted in the next day or two, weather permitting.
Last edited by rcdash; 11-30-2009 at 07:09 PM.
11-30-2009, 07:04 PM
#643
oh boy, I shoulda let you RTA my car. The drone at 3000 rpms was significant 
on a side note, thats another thing i'll have to borrow to touch up my 1/3 octave eq. I rta'd with an AudioControl RTA a few years ago, but my setup has changed fully since then
on a side note, thats another thing i'll have to borrow to touch up my 1/3 octave eq. I rta'd with an AudioControl RTA a few years ago, but my setup has changed fully since then
11-30-2009, 07:21 PM
#644
The noisy exhausts for FI is the only thing I regret to date about my build and I'm hoping to get it taken care of before we meet up this weekend!
If you want I can bring along the shockwave 1, 2, and large mufflers this weekend and you can provide another subjective opinion. Takes only a few mins to change out the axle backs once I get this evap canister tucked away.
12-14-2009, 05:46 AM
#648
Part number Part Description
64824CD000 Rear body and floor, Floor and rails, Bracket, Vapor canister, Vapor canister
I was waiting on the above part to relocate evap canister back to the stock location (dang evoTT) - I just learned it arrived at my home this morning.
I have shockwave TDX clips and rta completed, so just need to get this part installed, then I can whip through the others. Will try to do what I can tonight after work. On the other hand, it's been raining continuously here for the past week. Wed and Thu will be sunny though.
EDIT: It took some digging to get this part #, which I think every evoTT owner will need if they didn't retain their stock evap bracket to go back to any other exhaust. If this is the wrong part, I'm going to duct tape that sucker off to the side and finish the testing this week!!!!
My apologies for the delay.
EDIT: Update at 1 am EST - evap canister relocated and hoses reconnected! That part # above is the correct part to secure the evap canister in the stock location. One of the hoses was a PITA to get back to fit but with a 5/8" elbow I got it to work. I'll snap a few pics - but it's pretty straightforward - only fits one way.
Tomorrow I'm putting on the largest muffler and I'll update y'all in the evening or Wed.
64824CD000 Rear body and floor, Floor and rails, Bracket, Vapor canister, Vapor canister
I was waiting on the above part to relocate evap canister back to the stock location (dang evoTT) - I just learned it arrived at my home this morning.
I have shockwave TDX clips and rta completed, so just need to get this part installed, then I can whip through the others. Will try to do what I can tonight after work. On the other hand, it's been raining continuously here for the past week. Wed and Thu will be sunny though.
EDIT: It took some digging to get this part #, which I think every evoTT owner will need if they didn't retain their stock evap bracket to go back to any other exhaust. If this is the wrong part, I'm going to duct tape that sucker off to the side and finish the testing this week!!!!
My apologies for the delay.
EDIT: Update at 1 am EST - evap canister relocated and hoses reconnected! That part # above is the correct part to secure the evap canister in the stock location. One of the hoses was a PITA to get back to fit but with a 5/8" elbow I got it to work. I'll snap a few pics - but it's pretty straightforward - only fits one way.
Tomorrow I'm putting on the largest muffler and I'll update y'all in the evening or Wed.
Last edited by rcdash; 12-14-2009 at 09:19 PM.
12-15-2009, 06:40 AM
#649
UPDATE - got the largest set of mufflers on this am (no tips). Only had time for a quick cam phone pic (weather has been terrible - sorry for all the dirt):
The exhaust is much quieter but not as quiet as I was expecting. The drone at 2500-2800 rpms is gone. This is a real blessing for highway cruising at 65+ mph. There is new drone (or perhaps I'm just recognizing it now) at 1600-2000 rpms (45-55 mph in 5th gear on my 5AT). This reminds me now of my FastIntentions exhaust which had similar sized mufflers, an exhaust I liked but had to give up in the quest for a few more hp (silly me).
Let me see if I can find my review on g35driver for the FI exhaust as a comparo...
EDIT: Found my review of that exhaust here and it had the same issue (just below 2k rpms) but it mellowed a bit after breaking in and in warmer weather. Hmmm.... I will try to put some miles on it today and report back with sound clips and rta comparison to the shockwave TDX. I want to try the one with the 1/4 wavelength resonator canisters next...
Tony, any plans for a huge sideways oriented muffler akin to the stock muffler? There is a lot of unused space in the center section.
The exhaust is much quieter but not as quiet as I was expecting. The drone at 2500-2800 rpms is gone. This is a real blessing for highway cruising at 65+ mph. There is new drone (or perhaps I'm just recognizing it now) at 1600-2000 rpms (45-55 mph in 5th gear on my 5AT). This reminds me now of my FastIntentions exhaust which had similar sized mufflers, an exhaust I liked but had to give up in the quest for a few more hp (silly me).
Let me see if I can find my review on g35driver for the FI exhaust as a comparo...
EDIT: Found my review of that exhaust here and it had the same issue (just below 2k rpms) but it mellowed a bit after breaking in and in warmer weather. Hmmm.... I will try to put some miles on it today and report back with sound clips and rta comparison to the shockwave TDX. I want to try the one with the 1/4 wavelength resonator canisters next...
Tony, any plans for a huge sideways oriented muffler akin to the stock muffler? There is a lot of unused space in the center section
.
Last edited by rcdash; 12-15-2009 at 06:49 AM.
12-15-2009, 07:18 AM
#651
^^^ I think it's similar. There are sound clips of that posted on the net so maybe the ones I post will allow a comparison. Will try to get it broken in as much as possible today and get some sound clips up tomorrow, then switch out to the next set.
12-15-2009, 11:36 AM
#655
This looks like a perforated core but is not straight through (airflow branches around a center solid part of the core). This is the larger of the muffler designs. The other two are slightly smaller and look identical but have the different internals though they are straight through. I was hoping this one would be dead silent, so I'm a little disappointed. This does sound nice though and I'm sure it will appeal to many who want the sports car sound but not at obnoxious sound levels. It is significantly louder than stock, but I have 3.5" test pipes. I could be happy with it if the drone diminishes at 2k rpms. I am not sure if 6MT folks will experience any drone with this set up (if it is similar to the FI mufflers, where drone plagued 5AT owners primarily).
I will get video clips of all set ups at idle, highway cruising and WOT (if I can maintain traction at this temp, been under 50F). It's also has been raining for days. Wed and Thu supposed to be sunny...
EDIT: I haven't been speaking to the fitment, manufacturing quality, etc, because we all expect that to be top notch, and it is (cavaet: I have not tested with tips on the units). My reviews will focus on loudness and drone with rta to quantitate that and with audio clips to let you compare the sound for yourselves...
Last edited by rcdash; 02-03-2010 at 12:35 PM.
12-15-2009, 12:58 PM
#656
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This is disapointing.... I was hoping you would say it made a significant difference.
I wonder since I'm running 2.5" TPs and a 6mt, that would make a bigger difference?
I wonder since I'm running 2.5" TPs and a 6mt, that would make a bigger difference?
12-15-2009, 12:59 PM
#657
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This is disapointing.... I was hoping you would say it made a significant difference. I wonder since I'm running 2.5" TPs and a 6mt, that would make a bigger difference?
OT - sorry for the double post... this site is driving me crazy. Mods please delete one of these.
I wonder since I'm running 2.5" TPs and a 6mt, that would make a bigger difference?OT - sorry for the double post... this site is driving me crazy. Mods please delete one of these.
Last edited by BrianLG35C; 12-15-2009 at 01:02 PM.
12-15-2009, 01:04 PM
#658
Keep in mind I have 4 different designs here with me to try but I hear you Brian. I want the stock VQ sound back for easy daily driving, listening to audio, taking a client out in the car, etc. I'm hopeful that break-in will help and/or that the drone at least will be eliminated with the 1/4 wavelength resonator design. If I can isolate what changes each design has using the RTA on a FI vehicle, that may give Tony the data he needs to perfect a quiet exhaust for forced induction.
I'm just grateful that there is someone in this industry that cares! Thanks Tony for keeping those of us who want some peace and quiet on your radar.
I'm just grateful that there is someone in this industry that cares! Thanks Tony for keeping those of us who want some peace and quiet on your radar.
Last edited by rcdash; 12-15-2009 at 01:27 PM.
12-15-2009, 01:16 PM
#660
Raj, out of sheer curiosity have you tried to put back the stock exhaust system to see how the sound is?
There is always the option to go with the MD VQ Exhaust system. Not sure how much loss in power that will give though, but it's definitely more expensive then switching out just the axle backs. Have you looked into this option yet? I'm thinking about this route depending on the results from your test.
There is always the option to go with the MD VQ Exhaust system. Not sure how much loss in power that will give though, but it's definitely more expensive then switching out just the axle backs. Have you looked into this option yet? I'm thinking about this route depending on the results from your test.