Need interest in new product for KLX
#41
03-08-2011, 09:27 AM
Join Date: May 2006
Location: Pittsburgh, PA
Posts: 12,584
Someone here tried that a few years ago and never got it working. They have different connectors if I recall, and I think they tried to trace wires and get it hooked up right, with no luck. Doesn't mean it can't be done, but it wasn't straightforward, at least not until the first guy figures it out and tells the rest how to do it. 
I might be able to pick one up cheap, and was wondering. Depends how cheap i can get it, we will see what i can come up with. I have a couple buddies that can get me wiring diagrams.
#42
03-08-2011, 01:52 PM
B. The question of "How timing works". I really would like you to explore simple engine operation to answer this question. Advancing the ignition means to make the spark ignite closer to top dead center, thus making more power because you are igniting closer to full compression with the most energy possible.
This is actually incorrect unless the definition of ignition advance has been redefined recently, maybe with "change" and all that who knows. In the old days to advance the ignition meant that the plug fired farther before TDC not closer to it.
This is actually incorrect unless the definition of ignition advance has been redefined recently, maybe with "change" and all that who knows. In the old days to advance the ignition meant that the plug fired farther before TDC not closer to it.
#43
03-08-2011, 05:14 PM
Roadglider,
You are correct. "Advance" still means what it used to "to move or bring forward." In this case it means bringing the moment the spark plug creates and arc further ahead in time, or moving it before TDC.
Besides my explanation describing the nature of the momentum of the intake air you can look at it this way. If the combustion process were very, very slow the spark should occur at top dead center and instantly cause combustion. Of course this is an ideal situation that never happens and even at idle some spark advance is needed since it takes time for combustion to occur and as this is happening the engine is still rotating so spark advance "times" spark plug firing so that the expansion of combustion gases occurs at the optimum time as the piston is traveling down.
This optimum time is generally found on a dyno under a whole variety of engine speeds, loads, intake air temperatures, humidity levels, simulation of altitudes (air density), etc....
Since the timing changes at each engine speed level (RPM) since the piston is moving faster while the time for combustion to get going is more or less constant the ignition timing must be advanced more as engine speed increases.
Now the engineers and designers test the engine at a variety of "points" to find the ideal combination of efficiency and power at each test point. Noting the ideal spark advance, and throttle position if the engine is fuel injected.
In this manner they create a "map" of optimum engine performance. Now since you can't test every conceivable combination of variables they test as many as are needed and then have the computer (ignition/fuel injection module or engine's computer) interpolate instantly based on the raw data the correct operating parameters for the engine. This is why the various sensors on a car (mass air flow, etc) are necessary for proper running of the car. When a sensor fails the computer goes into a reduced efficiency mode where it keeps the engine running using the data it has and throws a warning light on the dash.
Modern engine even fine tune the operation of the engine to find optimum operating parameters constantly to adapt for engine wear. This one of the reasons modern electronic fuel injection, when done properly, is so great. It's like having the engineers under the hood constantly finding the optimum spark advance, air flow, and fuel (direct injection engines) along with other parameters like how strong of a spark and other things I'm not even aware of that are trade secrets.
If you remember the early versions of spark advance, when we used points on engines to time the spark, use centrifugal force to increase ignition advance with increasing engine speed. All of this stuff worked pretty well if you kept it tuned up. Back in the days when tune ups actually had meaning.
This is of course a very simple explanation. There are other parameters also monitored like detonation, which if detected will retard timing. A good system will slowly advance ignition timing until it just detects detonation to use every bit of octane in the current fuel being used in the engine so if you put in better gas you get more power, cheap gas, less power.
Imagine adding variable intake and exhaust valve timing into the mix and you see how complicated it can get. But you can also see how you can have an amazing performance engine at all engine speeds that gets good fuel economy.
This is how Hyundai is able to get 274HP from their 2 liter turbo on regular gas while passing all emissions regs and getting 33mpg highway!
With increasing demand for higher performance, higher fuel economy cars we are seeing a "reinvention" of the automobile engine. Mazda has recently introduced their sky-something engine with a 13:0 compression ratio and 160HP out of 2 liters with nearly 40mpg. Ford uses it in the new Focus as well. Sure you can get 160HP out of two liters with turbo charging but it's more expensive (says Mazda) or you can go with a high rpm engine, but then you don't have the torque and efficiency goes down with high engine rpm due to increased mechanical friction and air friction and other losses. Look at the mileage on the super strung Ferrari's or even a Honda Civic Si or S2000 and it ain't that good seeing how the engines are only 2 liters.
Anyway I apologize for going off topic here...
As to the original poster, seeing is believing if he can make the mods and show the power increase on a dyno then I'm in. The one thing he as going for him is the fact that it does appear the AU version does have more advanced ignition timing and supposedly more power. If all that is true and the cam timing is the same (or we can get cheap cams) and the power increase is significant (say 10 or more percent) and the power delivery is still good and he can get it going, then it seems like a worthwhile effort.
You are correct. "Advance" still means what it used to "to move or bring forward." In this case it means bringing the moment the spark plug creates and arc further ahead in time, or moving it before TDC.
Besides my explanation describing the nature of the momentum of the intake air you can look at it this way. If the combustion process were very, very slow the spark should occur at top dead center and instantly cause combustion. Of course this is an ideal situation that never happens and even at idle some spark advance is needed since it takes time for combustion to occur and as this is happening the engine is still rotating so spark advance "times" spark plug firing so that the expansion of combustion gases occurs at the optimum time as the piston is traveling down.
This optimum time is generally found on a dyno under a whole variety of engine speeds, loads, intake air temperatures, humidity levels, simulation of altitudes (air density), etc....
Since the timing changes at each engine speed level (RPM) since the piston is moving faster while the time for combustion to get going is more or less constant the ignition timing must be advanced more as engine speed increases.
Now the engineers and designers test the engine at a variety of "points" to find the ideal combination of efficiency and power at each test point. Noting the ideal spark advance, and throttle position if the engine is fuel injected.
In this manner they create a "map" of optimum engine performance. Now since you can't test every conceivable combination of variables they test as many as are needed and then have the computer (ignition/fuel injection module or engine's computer) interpolate instantly based on the raw data the correct operating parameters for the engine. This is why the various sensors on a car (mass air flow, etc) are necessary for proper running of the car. When a sensor fails the computer goes into a reduced efficiency mode where it keeps the engine running using the data it has and throws a warning light on the dash.
Modern engine even fine tune the operation of the engine to find optimum operating parameters constantly to adapt for engine wear. This one of the reasons modern electronic fuel injection, when done properly, is so great. It's like having the engineers under the hood constantly finding the optimum spark advance, air flow, and fuel (direct injection engines) along with other parameters like how strong of a spark and other things I'm not even aware of that are trade secrets.
If you remember the early versions of spark advance, when we used points on engines to time the spark, use centrifugal force to increase ignition advance with increasing engine speed. All of this stuff worked pretty well if you kept it tuned up. Back in the days when tune ups actually had meaning.
This is of course a very simple explanation. There are other parameters also monitored like detonation, which if detected will retard timing. A good system will slowly advance ignition timing until it just detects detonation to use every bit of octane in the current fuel being used in the engine so if you put in better gas you get more power, cheap gas, less power.
Imagine adding variable intake and exhaust valve timing into the mix and you see how complicated it can get. But you can also see how you can have an amazing performance engine at all engine speeds that gets good fuel economy.
This is how Hyundai is able to get 274HP from their 2 liter turbo on regular gas while passing all emissions regs and getting 33mpg highway!
With increasing demand for higher performance, higher fuel economy cars we are seeing a "reinvention" of the automobile engine. Mazda has recently introduced their sky-something engine with a 13:0 compression ratio and 160HP out of 2 liters with nearly 40mpg. Ford uses it in the new Focus as well. Sure you can get 160HP out of two liters with turbo charging but it's more expensive (says Mazda) or you can go with a high rpm engine, but then you don't have the torque and efficiency goes down with high engine rpm due to increased mechanical friction and air friction and other losses. Look at the mileage on the super strung Ferrari's or even a Honda Civic Si or S2000 and it ain't that good seeing how the engines are only 2 liters.
Anyway I apologize for going off topic here...
As to the original poster, seeing is believing if he can make the mods and show the power increase on a dyno then I'm in. The one thing he as going for him is the fact that it does appear the AU version does have more advanced ignition timing and supposedly more power. If all that is true and the cam timing is the same (or we can get cheap cams) and the power increase is significant (say 10 or more percent) and the power delivery is still good and he can get it going, then it seems like a worthwhile effort.
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