Blr243 wrote:So I’m sitting hear thinking who do I ask ..... my new cf moto 500 cc quad makes more noise than my old 250 cc Honda as one might expect. I bought a dB killer silencer exhaust on eBay. It’s not a replacement muffler. It’s an add on ... so after unwrapping it I turn on the bike and push the unit up against the pipe and yes I’m happy significant volume reduction.... I’m not interested In increased performance or decreased performance or having a nice fat sound. This add on is strictly to scare game less when I’m in the field. A bit of research on the net suggests I’m not goin to harm my engine by fitting this unit. I’m not sure. I don’t know jack about engines. I have heard that too much air restriction ( as is the case with a very efficient sound killer design) can damage my engine or maybe it causes over heating ? I don’t know. Should I be worried ?
bladeracer wrote:[ Now I've bought an electric motor conversion for it instead.
on_one_wheel wrote:bladeracer wrote:[ Now I've bought an electric motor conversion for it instead.
You have my attention.
E/V cars don't excite me yet but the Bike scene is a different story, I'm looking forward to watching that develop.
I'm waiting to see haw the Stark VARG goes, and the follow when the main players get the technology cranking
on_one_wheel wrote:I'm tickled pink that someone has considered my opinion potentially valuable
When talking non computer controlled, carby 4 stroke engines while skipping some of the finer volumetric efficiency details.
Typically, when you go the other way (free flowing, noisy system) , without tuning the engine to suit, you run the risk of lean fuel / air ratio (F/A) which is created by the effect of improved scavenging of the exhaust gasses, with improved scavenging the cylinder gets a better change of fresh fuel and air with less residual gases from the previous stroke that contain less dense hot gases, unburned fuel, with reduced oxygen.
Lean conditions can be hard on pistons exhaust valves due to the increased combustion temperature.
In real world terms the improved scavenging effect would rarely cause an issue with factory tuned engines as they are tuned on the rich side (safe side) of the perfect F/A ratio to allow for atmospheric and fuel quality variations.
However to gain the full benefits of an exhaust upgrade a jet change is necessary.
Now...
Being that potentially your going the other way with an add on that restricts the flow of exhaust gasses, it's possible that you'll actually be running a little richer, due to the opposing effects
I seriously doubt that you'll even notice the difference in F/A ratio without measuring equipment with only an exhaust ad-on, even then I'd bet it was an extremely small change.
A richer F/A will see a decrease in performance, decrease in exhaust gas temperature, reduced fuel economy, black exhaust smoke, and at it's worst on the extreme end, plug fowling and piston ring washing causing increased wear to the piston, piston rings and bore. There's simply no way that will happen without messing with jets or having some kind of carburettor issue.
If your worried, pay attention to the odour and colour of the exhaust gasses, I doubt you'll notice anything but If you do, you could start getting technical and do an plug chop to read its colour.
bigrich wrote:on_one_wheel wrote:I'm tickled pink that someone has considered my opinion potentially valuable
When talking non computer controlled, carby 4 stroke engines while skipping some of the finer volumetric efficiency details.
Typically, when you go the other way (free flowing, noisy system) , without tuning the engine to suit, you run the risk of lean fuel / air ratio (F/A) which is created by the effect of improved scavenging of the exhaust gasses, with improved scavenging the cylinder gets a better change of fresh fuel and air with less residual gases from the previous stroke that contain less dense hot gases, unburned fuel, with reduced oxygen.
Lean conditions can be hard on pistons exhaust valves due to the increased combustion temperature.
In real world terms the improved scavenging effect would rarely cause an issue with factory tuned engines as they are tuned on the rich side (safe side) of the perfect F/A ratio to allow for atmospheric and fuel quality variations.
However to gain the full benefits of an exhaust upgrade a jet change is necessary.
Now...
Being that potentially your going the other way with an add on that restricts the flow of exhaust gasses, it's possible that you'll actually be running a little richer, due to the opposing effects
I seriously doubt that you'll even notice the difference in F/A ratio without measuring equipment with only an exhaust ad-on, even then I'd bet it was an extremely small change.
A richer F/A will see a decrease in performance, decrease in exhaust gas temperature, reduced fuel economy, black exhaust smoke, and at it's worst on the extreme end, plug fowling and piston ring washing causing increased wear to the piston, piston rings and bore. There's simply no way that will happen without messing with jets or having some kind of carburettor issue.
If your worried, pay attention to the odour and colour of the exhaust gasses, I doubt you'll notice anything but If you do, you could start getting technical and do an plug chop to read its colour.
I agree. I used to build my own custom Holley carbs for my hot rod type stuff, and do a lot of my own tuning. Used to get it that close, on a chassis dyno I was maybe only one jet size out. Reading the plugs and exhaust colours was the secret. If all is correct, the ceramic insulator should be the colour of a cup of coffee. A light tan colour. A red/dark brown colour is rich and can wash the rings with too much fuel and damage the bore. White insulator with yellow electrode is lean, and pinging in the engine will cause damage. I think the assumption of restricting the exhaust will result in richening up the engine is correct
GQshayne wrote:bigrich wrote:on_one_wheel wrote:I'm tickled pink that someone has considered my opinion potentially valuable
When talking non computer controlled, carby 4 stroke engines while skipping some of the finer volumetric efficiency details.
Typically, when you go the other way (free flowing, noisy system) , without tuning the engine to suit, you run the risk of lean fuel / air ratio (F/A) which is created by the effect of improved scavenging of the exhaust gasses, with improved scavenging the cylinder gets a better change of fresh fuel and air with less residual gases from the previous stroke that contain less dense hot gases, unburned fuel, with reduced oxygen.
Lean conditions can be hard on pistons exhaust valves due to the increased combustion temperature.
In real world terms the improved scavenging effect would rarely cause an issue with factory tuned engines as they are tuned on the rich side (safe side) of the perfect F/A ratio to allow for atmospheric and fuel quality variations.
However to gain the full benefits of an exhaust upgrade a jet change is necessary.
Now...
Being that potentially your going the other way with an add on that restricts the flow of exhaust gasses, it's possible that you'll actually be running a little richer, due to the opposing effects
I seriously doubt that you'll even notice the difference in F/A ratio without measuring equipment with only an exhaust ad-on, even then I'd bet it was an extremely small change.
A richer F/A will see a decrease in performance, decrease in exhaust gas temperature, reduced fuel economy, black exhaust smoke, and at it's worst on the extreme end, plug fowling and piston ring washing causing increased wear to the piston, piston rings and bore. There's simply no way that will happen without messing with jets or having some kind of carburettor issue.
If your worried, pay attention to the odour and colour of the exhaust gasses, I doubt you'll notice anything but If you do, you could start getting technical and do an plug chop to read its colour.
I agree. I used to build my own custom Holley carbs for my hot rod type stuff, and do a lot of my own tuning. Used to get it that close, on a chassis dyno I was maybe only one jet size out. Reading the plugs and exhaust colours was the secret. If all is correct, the ceramic insulator should be the colour of a cup of coffee. A light tan colour. A red/dark brown colour is rich and can wash the rings with too much fuel and damage the bore. White insulator with yellow electrode is lean, and pinging in the engine will cause damage. I think the assumption of restricting the exhaust will result in richening up the engine is correct
On a carby engine maybe so, but this is an EFI engine. It has an air flow meter and an oxygen sensor to adjust parameters accordingly.
Blr243 wrote:Plug check is looking at the state of the spark plug ? And what am I looking for ? Dirty plug ?
Blr243 wrote:Thanks a lot men. Recommend name change for on one wheel. Sounds too clever to be on one wheel doin 150 k down the highway drunk at 2 am
cz515 wrote:I think the quad bike muffle might be too small but many people use steel wool in mufflers to decrease noise in cars.
Anyway having run a varex branded muffler that had a flap on it to decrease noise. It would bring the level of the car very low, think a Harley bike going past and then a standard 4 cylinder. Anyway i found if i ran the engine low revs and low loads it was fine. But definitely felt like something bad it's going to happen if giving it the beans. So be careful on your quad