It looks fast too!
07-19-2012, 04:45 AM
#111
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I have good news! I finished building the expansion chamber with the sound deadening material, and installed it last night. While it did not eliminate the rasp from the Q300, it sure did clean it up. As I mentioned before, the Q300 exhibits excessive rasp with its own mid-pipe when mated with an HFC or test pipe. I will need to do a back-to-back comparison to see whether my mid-pipe makes the rasp much quieter than the Q300 mid-pipe, but the sound quality of the Q300 is definitely better with my mid-pipe. It's actually more of a "sporty rasp" than it was before, and the intensity is consistent across the RPM range (unlike before). I'll do a back-to-back in a few days, and will also make some videos and sound recordings. I also plan to make another adapter pipe for my 3" single Magnaflow muffler, and will repeat the drone tests for that.
A second bit of good news is that I found a supplier for perforated megaphones, so that addition won't drive cost up as much as I feared it would.
In the mean time, would those of you who are seriously considering buying please let me know? Also, if the only thing holding you back from buying is that it doesn't have a muffler, please let me know what you would be willing to pay for the addition of a single exit muffler.
A second bit of good news is that I found a supplier for perforated megaphones, so that addition won't drive cost up as much as I feared it would.
In the mean time, would those of you who are seriously considering buying please let me know? Also, if the only thing holding you back from buying is that it doesn't have a muffler, please let me know what you would be willing to pay for the addition of a single exit muffler.
07-19-2012, 08:24 AM
#112
In the mean time, would those of you who are seriously considering buying please let me know? Also, if the only thing holding you back from buying is that it doesn't have a muffler, please let me know what you would be willing to pay for the addition of a single exit muffler.
07-19-2012, 01:29 PM
#113
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I've been PM'ed by 3 members that are considrering a purhcase, which is great news! I don't count any of those to be commitments for purchase, but I really want to have a feel for possible sales.
I figured it would be better to answer the questions from those PM's in the thread, in order to clear it up for everyone.
I have tested my mid-pipe with a 2.5" single, which actually had a internal restriction that looked smaller than 2", and it performed almost identically to my 3" straight-through single. However, all of the other mufflers I tested were 3", since my plan at the time that I purchased the mufflers was for the system to be 3" all the way through. Also, since drone is not an issue with my mid-pipe, the 3" mufflers really weren't loud unless I wanted them to be. Honestly, the 3" dingle I showed earlier in the thread is actually so quiet that I thought many people would complain that it was too quiet.
I figured it would be better to answer the questions from those PM's in the thread, in order to clear it up for everyone.
I have tested my mid-pipe with a 2.5" single, which actually had a internal restriction that looked smaller than 2", and it performed almost identically to my 3" straight-through single. However, all of the other mufflers I tested were 3", since my plan at the time that I purchased the mufflers was for the system to be 3" all the way through. Also, since drone is not an issue with my mid-pipe, the 3" mufflers really weren't loud unless I wanted them to be. Honestly, the 3" dingle I showed earlier in the thread is actually so quiet that I thought many people would complain that it was too quiet.
07-19-2012, 01:40 PM
#114
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I cant say that I am in a position to buy this in the near future but I am very interested in the long run. I really like the idea of well thought out innovations for the car which are made by people who own the car. As others have pointed out, many many people on this site drop around 1k for a header that shows little to no gains. The stock header is very well designed while the mid pipe is a known weak point. Why would you spend a ton of money to improve something that is already fantastic? Finally, for those people that want the HP gains of this pipe on the cheap, go get a test pipe. I tried it and I couldnt stand the smell so this is something Im very interested in.
-Gernby
Interesting idea about selling just the magic part rather than trying to make a psudo bolt on product. If you make a central part that is as simple as possible and tell people the right distances to weld it from the header then you could achieve two things. First, the product would be cheaper up front and that could result in more buyers who are welders themselves or have connections and could get welds done on the cheap or people who just find 1k hard to swallow up front. Second, people might be able to use the mid-pipe from their current exhaust as materials. This would help those people that dont like the idea of buying a new exhaust just to throw away the mid-pipe. It looks like most of the people that are actually interested in this are people who are willing to put in a little to make things work.
side question: so the drone problem is coming almost entirely from the fact that the cat is too close to the header. Do I have this right?
-Gernby
Interesting idea about selling just the magic part rather than trying to make a psudo bolt on product. If you make a central part that is as simple as possible and tell people the right distances to weld it from the header then you could achieve two things. First, the product would be cheaper up front and that could result in more buyers who are welders themselves or have connections and could get welds done on the cheap or people who just find 1k hard to swallow up front. Second, people might be able to use the mid-pipe from their current exhaust as materials. This would help those people that dont like the idea of buying a new exhaust just to throw away the mid-pipe. It looks like most of the people that are actually interested in this are people who are willing to put in a little to make things work.
side question: so the drone problem is coming almost entirely from the fact that the cat is too close to the header. Do I have this right?
07-19-2012, 02:56 PM
#116
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I installed the OEM cat last night with the standard Q300 (without my mid-pipe), and tested it for drone at WOT and also at a cruise throttle. The results were similar to those from the HFC. However, I noticed that I made a mistake while processing some of the HFC recordings. I forgot to click on of the buttons, and the result was that the sound level for the cruise throttle plot was greatly overstated. I have fixed that for the plots below.
I've also included a screenshot of the application that I use to process the sound files. It doesn't look very "snazzy" on purpose, since I don't want to draw any attention if I run it at work. Anyway, the moment that I captured the screen shot below was right when drone was peaking at about 3500 RPMs, which is why the only sound you really see on the spectrum analyzer is at 112 Hz and 224 Hz. When drone is low, there would be many, many frequencies bouncing around.
BTW, there was virtually zero rasp with the OEM cat. Aside from the drone, I like the way it sounds.
Cruise Throttle
Full Throttle
I've also included a screenshot of the application that I use to process the sound files. It doesn't look very "snazzy" on purpose, since I don't want to draw any attention if I run it at work. Anyway, the moment that I captured the screen shot below was right when drone was peaking at about 3500 RPMs, which is why the only sound you really see on the spectrum analyzer is at 112 Hz and 224 Hz. When drone is low, there would be many, many frequencies bouncing around.
BTW, there was virtually zero rasp with the OEM cat. Aside from the drone, I like the way it sounds.
Cruise Throttle
Full Throttle
07-19-2012, 03:01 PM
#117
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The Y axis is a linear representation of the sound level. It is not standardized by any "unit", like dB or SPL. It is just a value from the FFT algorithm that I run on the digital recording.
07-19-2012, 03:03 PM
#118
Originally Posted by blasphemy101' timestamp='1342464894' post='21864031
[quote name='Gernby' timestamp='1342457501' post='21863601']
I agree that the sound from a muffler does change as it breaks in, but I've tested 8 mufflers with my system, and none of them were raspy like this. I actually think it's more common for mufflers to get louder as they age, since they tend to blow the fiberglass packing out over time.
I agree that the sound from a muffler does change as it breaks in, but I've tested 8 mufflers with my system, and none of them were raspy like this. I actually think it's more common for mufflers to get louder as they age, since they tend to blow the fiberglass packing out over time.
My Berk 3" Single Exhaust noticeably quieted down over a period of about 2 weeks.
[/quote]
Either way, thats not really the point of this thread. Gernby, sorry for bringing it up and half way derailing your thread lol