Dynojet Kit for 2007 KLX250
#41
04-27-2016, 05:56 PM
Anyway, you've made a great choice for a first step - throw it on, doup 140/2N, lidless, and enjoy..
#42
04-27-2016, 06:02 PM
No one has proof of "too loud" vs "not too loud".. You will decide for your bike and your riding area whether a quiet tip is called for.. I do not believe this quiet tip -http://www.motorcycle-superstore.com/38465/i/fmf-power-core-4--q4-quiet-insert-w--spark-arrestor - will need a carb setup change from 140/2N..
#43
04-27-2016, 06:04 PM
96db is extremely loud.
Going from 85db to 88db results in a bike that literally sounds twice as loud. The Quietcore is a high performing slip on that is better suited to trail riding and street use. It's loud enough by itself to be annoying, but isn't a race pipe like the Powercore.. which is fine for a closed circuit motocross track but not appropriate for riding in the national forests or in your local neighorhood trails. People hear that noisy racket and hate dirt bikes as a result.
"Sound levels are measured in units called decibels (dB). The decibel scale is an exponential scale rather than a linear scale. This means that the intensity or energy imparted by the sound waves doubles for every 3 dB in the sound measurement.
The decibel level of the exhaust is important because of how we perceive it, and its effect on us psychologically and physically. If you’re driving a hot muscle car, you want it to sound powerful. On the other hand, if you’re driving a $65,000 Lexus, Mercedes or BMW 7-Series, quiet is synonymous with quality. And if you’re stuck behind the wheel of a 20 year-old beater, noise is the least of your worries. Noise levels are important because too many decibels can damage our hearing (and close trails - queen of spades). Noise induced hearing loss can occur with prolonged exposure to loud noise, or even short term exposure to loud sounds. Any prolonged noise over 85 dB is considered to be potentially dangerous." Exhaust Noise: How Much is Too Much?
Going from 85db to 88db results in a bike that literally sounds twice as loud. The Quietcore is a high performing slip on that is better suited to trail riding and street use. It's loud enough by itself to be annoying, but isn't a race pipe like the Powercore.. which is fine for a closed circuit motocross track but not appropriate for riding in the national forests or in your local neighorhood trails. People hear that noisy racket and hate dirt bikes as a result.
"Sound levels are measured in units called decibels (dB). The decibel scale is an exponential scale rather than a linear scale. This means that the intensity or energy imparted by the sound waves doubles for every 3 dB in the sound measurement.
The decibel level of the exhaust is important because of how we perceive it, and its effect on us psychologically and physically. If you’re driving a hot muscle car, you want it to sound powerful. On the other hand, if you’re driving a $65,000 Lexus, Mercedes or BMW 7-Series, quiet is synonymous with quality. And if you’re stuck behind the wheel of a 20 year-old beater, noise is the least of your worries. Noise levels are important because too many decibels can damage our hearing (and close trails - queen of spades). Noise induced hearing loss can occur with prolonged exposure to loud noise, or even short term exposure to loud sounds. Any prolonged noise over 85 dB is considered to be potentially dangerous." Exhaust Noise: How Much is Too Much?
#45
04-27-2016, 06:07 PM
It's science. Decibels are measurable. If sound wasn't measurable there wouldn't be sound restrictions at supercross and motocross events at the pro level, and everyone would run straight pipes like we did in the 70s.
Quiet Please! - Two Bikers Tell a Tale of Sound
Quiet Please! - Two Bikers Tell a Tale of Sound
#46
04-27-2016, 06:09 PM
96db is extremely loud.
Going from 85db to 88db results in a bike that literally sounds twice as loud. The Quietcore is a high performing slip on that is better suited to trail riding and street use. It's loud enough by itself to be annoying, but isn't a race pipe like the Powercore.. which is fine for a closed circuit motocross track but not appropriate for riding in the national forests or in your local neighorhood trails. People hear that noisy racket and hate dirt bikes as a result.
"Sound levels are measured in units called decibels (dB). The decibel scale is an exponential scale rather than a linear scale. This means that the intensity or energy imparted by the sound waves doubles for every 3 dB in the sound measurement.
The decibel level of the exhaust is important because of how we perceive it, and its effect on us psychologically and physically. If you’re driving a hot muscle car, you want it to sound powerful. On the other hand, if you’re driving a $65,000 Lexus, Mercedes or BMW 7-Series, quiet is synonymous with quality. And if you’re stuck behind the wheel of a 20 year-old beater, noise is the least of your worries. Noise levels are important because too many decibels can damage our hearing (and close trails - queen of spades). Noise induced hearing loss can occur with prolonged exposure to loud noise, or even short term exposure to loud sounds. Any prolonged noise over 85 dB is considered to be potentially dangerous." Exhaust Noise: How Much is Too Much?
Going from 85db to 88db results in a bike that literally sounds twice as loud. The Quietcore is a high performing slip on that is better suited to trail riding and street use. It's loud enough by itself to be annoying, but isn't a race pipe like the Powercore.. which is fine for a closed circuit motocross track but not appropriate for riding in the national forests or in your local neighorhood trails. People hear that noisy racket and hate dirt bikes as a result.
"Sound levels are measured in units called decibels (dB). The decibel scale is an exponential scale rather than a linear scale. This means that the intensity or energy imparted by the sound waves doubles for every 3 dB in the sound measurement.
The decibel level of the exhaust is important because of how we perceive it, and its effect on us psychologically and physically. If you’re driving a hot muscle car, you want it to sound powerful. On the other hand, if you’re driving a $65,000 Lexus, Mercedes or BMW 7-Series, quiet is synonymous with quality. And if you’re stuck behind the wheel of a 20 year-old beater, noise is the least of your worries. Noise levels are important because too many decibels can damage our hearing (and close trails - queen of spades). Noise induced hearing loss can occur with prolonged exposure to loud noise, or even short term exposure to loud sounds. Any prolonged noise over 85 dB is considered to be potentially dangerous." Exhaust Noise: How Much is Too Much?
Thx for the info. Our local trails have a 93-96 limit. I live in Ontario and most of our trails are away from residential areas. I just don't want to be higher than the allowed local limits
Kevin
#47
04-27-2016, 06:09 PM
I have the luxury of owning two systems. So I can say with back to back comparisons that the Megabomb+PC4 is more quiet than a DG-R+stock header. So to generalize, I know a full system CAN be more quiet than just a slipon.
#48
04-27-2016, 06:16 PM
Like Klxster wrote above the megabomb (not powerbomb) header will reduce volume by 1-2 db (a noticeable difference.. remember every 3 db results in a change in a doubling of perceived volume -- that can work both ways, getting louder and quieter).
I didn't want to put out $240 for the megabomb, but did so since I ride in some urban/suburban areas that have lots of houses nearby. I don't want to have those trails shut down from homeowners calling 911 about noisy dirt bikes riding behind their houses.
#49
04-27-2016, 06:17 PM
Kevin, as with one of my local riding ranches, they will use a standard measuring method with a meter.. If your PC4 passes, great.. If not, time for the quiet tip.. Then if not, time for the Megabomb.. Then if not, sell the system - I know I'm a potential buyer..
I know of no data/chart that allows us to lookup this data..
I know of no data/chart that allows us to lookup this data..
#50
04-27-2016, 06:32 PM
You can pick up a Chinese Megabomb for $99 right now. Here's a thread: https://www.kawasakiforums.com/forum...ck-offs-41201/
If you literally just ordered the Powercore, you can call the shop and have them switch to a Quietcore.. both of them are loud.. just one of them is not designed for a motocross track where noise isn't an issue.
If you literally just ordered the Powercore, you can call the shop and have them switch to a Quietcore.. both of them are loud.. just one of them is not designed for a motocross track where noise isn't an issue.