Well, in my case it is actually LOUDER with the windows up which is really the problem: I can't ever escape the resonance :-\ I agree that it is a factor of the system design and I think specifically the pipe volume and resonance of the specific material chosen. I have the stainless version of the system (409 stainless) and several other guys with the stainless system have mentioned similar resonance. Aluminized versions of the same system don't seem to drone. I drive the car 4 seasons up here in the snow belt of PA, so I need the stainless.
The vendor really went out of their way to try to help me by sending new front and rear sections with Vibrant resonator and muffler, but the sound and resonance of the system really didn't change at all ... surprisingly. I also started with the stock downpipe and later added a 3" catted down pipe with no change in sound/resonance. If I had to guess I would say the issue has to be in the resonance of the "Z" shaped mid pipe since that's the only thing that hasn't been changed. I wish I had a Go-Pro to mount under the car. The resonance is so strong I can just imagine the pipe vibrating like a tuning fork LOL. The first thing people mention is rubbing/interference, but trust me I have been under the car about 6 times to try to solve this and there is plenty of clearance everywhere. The resonance starts before 3k RPM which is a problem for highway cruising. It's quiet below ~3200 RPM when not under load, but part-throttle acceleration really gets loud inside the car and when cruising at 70 MPH that's just the wrong RPM. At 3500 RPM either part throttle or decelerating it's positively deafening inside the car ... windows up or down doesn't matter.
Back to the original thread: It's a shame because I love the sound of the car from the outside, but I just can't deal with the brain-vibrating resonance inside. My current first choice as a replacement is the Scorpion 3" 304 stainless system, but it's pricey. I have first-hand reports that it doesn't drone at all though and I do like the sound of it a lot. I liked the video clips of the MBRP which is what got me to this thread. If you can give me some more details about what it sounds like inside the car especially with the windows up then that will help me a lot. I am okay with loud outside the car, but I want it to be quiet inside when cruising and at least not resonate my brain when accelerating or decelerating.
The vendor really went out of their way to try to help me by sending new front and rear sections with Vibrant resonator and muffler, but the sound and resonance of the system really didn't change at all ... surprisingly. I also started with the stock downpipe and later added a 3" catted down pipe with no change in sound/resonance. If I had to guess I would say the issue has to be in the resonance of the "Z" shaped mid pipe since that's the only thing that hasn't been changed. I wish I had a Go-Pro to mount under the car. The resonance is so strong I can just imagine the pipe vibrating like a tuning fork LOL. The first thing people mention is rubbing/interference, but trust me I have been under the car about 6 times to try to solve this and there is plenty of clearance everywhere. The resonance starts before 3k RPM which is a problem for highway cruising. It's quiet below ~3200 RPM when not under load, but part-throttle acceleration really gets loud inside the car and when cruising at 70 MPH that's just the wrong RPM. At 3500 RPM either part throttle or decelerating it's positively deafening inside the car ... windows up or down doesn't matter.
Back to the original thread: It's a shame because I love the sound of the car from the outside, but I just can't deal with the brain-vibrating resonance inside. My current first choice as a replacement is the Scorpion 3" 304 stainless system, but it's pricey. I have first-hand reports that it doesn't drone at all though and I do like the sound of it a lot. I liked the video clips of the MBRP which is what got me to this thread. If you can give me some more details about what it sounds like inside the car especially with the windows up then that will help me a lot. I am okay with loud outside the car, but I want it to be quiet inside when cruising and at least not resonate my brain when accelerating or decelerating.
I don't have the MBRP system now. I have another system and I am avoiding mentioning who's system it is because I don't want to give them bad press. They have been really good about trying to fix the system and address my complaints, but in the end it's just a basic design issue I think. I am ready to move on and replace it with something that sounds like I want it to. The system I have would be great for a track-only car because it doesn't resonate at all at full throttle. It's just when part-throttle accelerating or decelerating like in my video. So the Scorpion is top on my list, but pricey. If I can determine the interior sound characteristics of the MBRP system then I might go that way. The MRT is too loud, and the Cobb seems too "zingy/buzzy". The Magnaflow is too quiet.
