Eliminating drone with helmholtz resonators...Let's get technical
#17
OK, so I used sqrt(gamma * R/M * T), where gamma is the adiabatic index, R is the molar gas constant, M is the mean molar mass of the gas mixture in kg, and T is the temperature of the exhaust gasses toward the end of the exhaust in kelvin (I used 400 degrees F, which is 477.6 kelvin).
This is sqrt(1.3147 * 8.31451/0.027925 * 477.5944) = 432.379 m/s for the speed of sound at the end of the exhaust. Anything I missed? This seems to be working better in the calculations.
This is sqrt(1.3147 * 8.31451/0.027925 * 477.5944) = 432.379 m/s for the speed of sound at the end of the exhaust. Anything I missed? This seems to be working better in the calculations.
#20
#21
Will do. I had originally planned on doing it this week, but unfortunately I'm having trouble getting one of the nuts off on my ART pipes (it's stripped). Took it to a shop on Monday and they wanted to replace my entire header. I still think I can get it off with enough work, so that will be the first thing I have to get done.
#25
I just used my iPhone. I took some recordings and emailed the files to myself, then used Audacity on my computer to find the loudest frequencies. There's also an iPhone app you can use to view it in realtime called SignalScope Pro, but I found that a little harder since I have to be driving while using it
You could probably also bring your laptop in your car and used that too, if you have a mic for it.
You could probably also bring your laptop in your car and used that too, if you have a mic for it.
#26
The Shockwave TDX2 is an awesome exhaust for sure, but I have a sedan and the options for it are very limited. Most of the sedan exhausts don't even sound as good as the stock coupe one. So for me, custom was the way to go. Plus, once I am able to get this working properly, I'll be able to apply it to any cars I have in the future for a drone-free experience
#28
Just an update:
Still don't have the stripped nut off. I've bought a few different wrenches and sockets from Sears to try and get it off, with no luck so far. If it was one of the other 2 holes with a stripped nut and not the one with the stud it would be much easier. There's very little room to work with.
And I'm changing out my valve covers right now since they're leaking pretty bad, but once this is done I can work on the nut again.
My buddy who helped me build the exhaust has a turbo SpecV Sentra, so we'll probably do this for his car first. He wants an electric cut-out on his car, so the plan is to put it at the end of the resonator so he will have no drone with it closed, and he can still open it up when he wants it loud
Still don't have the stripped nut off. I've bought a few different wrenches and sockets from Sears to try and get it off, with no luck so far. If it was one of the other 2 holes with a stripped nut and not the one with the stud it would be much easier. There's very little room to work with.
And I'm changing out my valve covers right now since they're leaking pretty bad, but once this is done I can work on the nut again.
My buddy who helped me build the exhaust has a turbo SpecV Sentra, so we'll probably do this for his car first. He wants an electric cut-out on his car, so the plan is to put it at the end of the resonator so he will have no drone with it closed, and he can still open it up when he wants it loud
#30