Need to add a resonator. Sizing? Magnaflow Race Mufflers?
#1
Need to add a resonator. Sizing? Magnaflow Race Mufflers?
I blew over 102db at an AutoX yesterday. So I need to add a resonator to my ARTech exhaust. Right now it's a Maxim Works header, and 2.5'' from the collector to the back of the car with one 6'' round Magnaflow at the end. I would like to add one in the middle somewhere, but I need some input on sizing. I measured and the length is not what concerns me, but the width from the transmission/trans tunnel.
Anyone have experience with the Magnaflow "race" mufflers? They seem to be a lot shorter than the standard resonators.
This is my exhaust.
These are the resonators I'm looking into. What should fit there, and bring my car down to the low 90db?
http://www.summitracing.com/parts/MPE-14156/
http://www.summitracing.com/parts/MPE-10416/ (comes in a 14, 18, 20'' length)
Anyone have experience with the Magnaflow "race" mufflers? They seem to be a lot shorter than the standard resonators.
This is my exhaust.
These are the resonators I'm looking into. What should fit there, and bring my car down to the low 90db?
http://www.summitracing.com/parts/MPE-14156/
http://www.summitracing.com/parts/MPE-10416/ (comes in a 14, 18, 20'' length)
#3
Yeah, that's the question. As long as it can fit.... lol
I'll get back down there with a measuring tape and try to figure it out. It's just hard to measure for roundness and taking into account any exhaust movement. If I can I want to get the biggest/longest one since I DD this and driving around with ear plugs sucks.
I'll get back down there with a measuring tape and try to figure it out. It's just hard to measure for roundness and taking into account any exhaust movement. If I can I want to get the biggest/longest one since I DD this and driving around with ear plugs sucks.
#5
I was once black flagged in my M3…was about 4 dB over the limit. Fix it or you can't race next time, okay I'll sort it out.
So what I did was measure SPL at home at a constant 3000 RPMs, no load with the meter 10 feet from the exhaust tip. My thought was that if I could get some amount over a 4 dB drop under those conditions, the much louder sound at higher revs and load would also drop by around the same amount.
I added a magnaflow crossover/X pipe resonator and noted that this cut dBs about 5-6 dB's. Encouraging. Primarily it cut the higher frequencies which are what tend to get you at sound limited events due to the fact that they use the A scale (which emphasizes higher frequencies). The car still sounded good and the tone was deep. Some of the dB drop came from the resonator's action, and some possibly from the X-pipe aspect.
Success! At the next event my levels were around 6 dB lower which gave me about 2 dBs to spare.
It's hard to get consistent readings for event sound for a variety of reasons. However the quick and dirty test I did helped me find a solution quickly so that I did not have to worry too much. Had the magnaflow only cut 2 dB then I'd have gone with a large one.
You could also add a larger volume rear muffler if the resonator does not cut the SPL enough.
So what I did was measure SPL at home at a constant 3000 RPMs, no load with the meter 10 feet from the exhaust tip. My thought was that if I could get some amount over a 4 dB drop under those conditions, the much louder sound at higher revs and load would also drop by around the same amount.
I added a magnaflow crossover/X pipe resonator and noted that this cut dBs about 5-6 dB's. Encouraging. Primarily it cut the higher frequencies which are what tend to get you at sound limited events due to the fact that they use the A scale (which emphasizes higher frequencies). The car still sounded good and the tone was deep. Some of the dB drop came from the resonator's action, and some possibly from the X-pipe aspect.
Success! At the next event my levels were around 6 dB lower which gave me about 2 dBs to spare.
It's hard to get consistent readings for event sound for a variety of reasons. However the quick and dirty test I did helped me find a solution quickly so that I did not have to worry too much. Had the magnaflow only cut 2 dB then I'd have gone with a large one.
You could also add a larger volume rear muffler if the resonator does not cut the SPL enough.
#6
Yeah, well I measured myself before going down with a meter from the side, 50 feet away driving by WOT. The same way my home club measures and I was b/w 96-97. I figured 1-2db wouldn't matter but they measured me at over 100. BUT that was also off the start from behind the car. Next to a building...
In any case, I bought the 18'' body magnaflow and am going to put it in tommorow.
In any case, I bought the 18'' body magnaflow and am going to put it in tommorow.
#7
Yeah, well I measured myself before going down with a meter from the side, 50 feet away driving by WOT. The same way my home club measures and I was b/w 96-97. I figured 1-2db wouldn't matter but they measured me at over 100. BUT that was also off the start from behind the car. Next to a building...
In any case, I bought the 18'' body magnaflow and am going to put it in tommorow.
In any case, I bought the 18'' body magnaflow and am going to put it in tommorow.
#11
Yeah, well I measured myself before going down with a meter from the side, 50 feet away driving by WOT. The same way my home club measures and I was b/w 96-97. I figured 1-2db wouldn't matter but they measured me at over 100. BUT that was also off the start from behind the car. Next to a building...
In any case, I bought the 18'' body magnaflow and am going to put it in tommorow.
In any case, I bought the 18'' body magnaflow and am going to put it in tommorow.