[url=https://classicgoldwings.com/forum/viewtopic.php?p=137673#p137673:12jzgpsu said:
wilcoy02 » Thu Dec 18, 2014 10:47 am[/url]":12jzgpsu]
Paul is teaching me what the c5 is all about that I have installed. I have not a clue about this kind of information.
With him keeping it very basic I am learning. So give him some time to get into the meat of this subject, so I can explain what the c5 is about while on my trip next summer.
Thank you.
My goal was first to be sure everyone understands what "timing" and "load" really are. Dan is helping us calibrate a VOES switch for use on Goldwings and I know from phone calls and emails that many people don't really grasp what the heck a timing curve even means.
So before we started talking about changing curves, adding VOES parts, and setting vacuum.......we needed to explain basics.
Maybe right now I should summarize what we've discussed so far. If there is point that is confusing, lets review before moving on. Once we all understand what the VOES does, then we can talk about the how/why you might want to bypass it (the hot rodders).
1) The term "Timing" or "Timing Curve" describes the matching of FUEL IGNITION (via spark plug) to the location of the PISTON/CRANK which is always moving.
2) The "timing" of the spark event changes as piston speed increases (even on a lawn mower). This means as the piston moves toward the top faster, we must ignite the fuel sooner, giving it time to burn and EXPAND at the right time for maximum power.
3) The "timing" of the spark event must match the BURN RATE of the fuel you are using (lets say 89 octane unleaded) and the rpm of the engine at that point, to maximize efficiency of the expanding fuel pushing down onto the piston.
3) As your engine LOAD increases, the fuel BURN RATE becomes faster. Regardless of what rpm your engine is running, the timing needs to be reduced as the fuel burn rate becomes faster.
!!! Take a moment and read those 3 items again. Your piston moves slower at idle so the spark plug ignites the fuel fairly close to the top (maybe 20 degrees of crank rotation away from TDC) but as the piston begins coming up faster, we need to ignite the fuel sooner (say 30 or 40 degrees before the top) in order for the "Maximum Cylinder Pressure" to happen at the correct time. If that doesn't happen we lose power (efficiency). All this talk about timing is simply a method of using your gasoline to push down the piston in the most EFFICIENT way possible.
4) Two methods can be used to handle an increased engine LOAD. You can down shift to a lower gear which reduces load mechanically via gear reduction. You can also reduce the timing so the spark timing matches the fuel burn rate better (retard timing).
If we shift to a lower gear, problem solved. If we prefer to stay in a higher gear, we need to change timing. There are several ways. Use toggle switches, use a rotary type switch, use a VOES to do it automatically. That is what this thread is all about.
