C5 using a VOES switch

[wilcoy02]

I can not wait to hit mountains with my loaded trailer either. I have 7 months yet!!

Nice to see the pretty colored lines but I know nothing of what they are telling me. That is a subject that I am ignorant.

 

[C5Performance]

Dan I have your VOES packed up and heading out tomorrow morning.
Luckily I purchased a 5" switch, as I had read that was most likely the one you'd need.
Thanks for sharing!!

We can use your data to decide what the second curve in the M Series should be.

 

[C5Performance]

wilcoy02 » Sun Dec 14, 2014 7:33 pm[/url]":35j9bm3f]
Nice to see the pretty colored lines but I know nothing of what they are telling me. That is a subject that I am ignorant.

Wes please allow me to explain this. We know there are quite a few readers baffled by the charts.
First I am going to explain a simple timing chart, so you understand timing and load. After you grasp that, I will explain further what Dan is doing, why timing is reduced, and the relationship between LOAD and TIMING.

The first drawing explains FUEL BURN.

Gasoline takes a certain amount of "time" to burn, correct? It begins to burn at the sparkplug, moves outward, and expands as this occurs. The expansion of the burning fuel causes a severe rise in pressure. Why is this important? The rise in pressure is what pushes your piston downward (rotating the crankshaft as this happens) and keeps your bike running and moving forward.

If you ignite the fuel too soon, the pressure builds before your piston reaches TDC (the top) and your piston has no mechanical leverage to push downward again. If you ignite the fuel too late, the pressure builds after the piston has passed the sweet spot where it has awesome leverage against the crankshaft. This means you lost power, wasted fuel, and probably are still burning fuel as it's dumped into your exhaust system.

Now look at the picture. The numbers on the bottom describe "timing advance" but you can think of this as a TIME chart.
Maximum cylinder pressure occurs just after TDC (the orange line).
Your bike is idling in your driveway? It is operating via the top line (takes 40 degrees before TDC to reach maximum pressure
Your bike is riding down the freeway full loaded? It is operating via the middle line
Your bike is towing a trailer full of kiln dried oak lumber? ....yes, probably it is operating via the lower line.

The harder your engine works, the faster your fuel burns, and the less "lead time" it needs to reach max pressure.

 

[C5Performance]

Your timing is matched to your engine compression and load.
As your engine comes under an increased load (climbing hills, pulling trailer, added rider, high compression pistons added) you must do one of two things to avoid engine detonation:

1) decrease load - such as down shifting to a lower gear

-or-

2) decrease the lead time (we just call it "timing") of the spark event, so the burn rate is better matched to the faster burning fuel.


Does this make sense so far?

I cannot discuss timing curves until you full understand what we are trying to accomplish.

 

[mcgovern61]

opcorn: Got It! Next!

 

[wilcoy02]

Makes sense.
Thank You

 

[C5Performance]

I will be sharing information that is not always "100% correct". Once everyone understands a concept we can move forward and clarify things a bit more. There will be no schedule...we share information at whatever pace works.

The next picture is a "timing curve". Why can't we just set timing at a certain place and leave it alone?

Because as engine speed increases, we must start burning the gasoline farther ahead of time because the piston reaches TDC (the top of its travel) faster and faster. Remember, it is all about reaching maximum cylinder pressure at an exact spot every time.

Light it too soon...detonation and other issues.
Light it too late...lost power and other issues.

So every manufacturer uses a simple chart to show how far ahead of time the spark plug ignites the fuel before the piston reaches TDC.
This "curve" is a simple straight line, and is not perfect. It would operate most engines but is not ideal. This is a starting point to understanding what a "curve" really is.

 

[C5Performance]

Last post of the evening:

Wes rides his motorcycle down a flat road and the timing curve I just shared seems to work just fine.
The timing of his spark is correct for the rate of fuel burn in his engine. Things are looking good and Wes is on his way to Alaska.

But....now he crosses the Mississippi River in Davenport Iowa. He climbs out of the river valley (takes about 5 miles) and his engine is struggling under this new LOAD. His engine has become more EFFICIENT under this load, and now his ignition is lighting the fuel too early!

If Wes wants to finish the trip without blowing a hole in his engine, he must continue downshifting until his engine's efficiency is back to an acceptable level.

***he could also run higher octane fuel that burns slower, but on flat ground it would burn TOO slow***

So if the YELLOW timing line is correct for flat ground, how do you get your engine to follow the pink timing curve needed for higher LOADS?

What if we could tell the ignition to change curves? This would not be possible using points or most aftermarket ignitions, but we can using the Power Arc based C5 ignition. All we need is a toggle/rotary/vacuum switch.

Please ask questions at this point before we move on.

 

[joedrum]

yes this is some rather super stuff ... truth is a c5 is the first time ignition can be dial in just like a carb ... have different setting for as it applies to load ...i have been aware of this situation from the get go on c5 as me paul talked about it in depth and have tested load many times on hooch ...unlike what dan said i got yrs upon yrs as being a farmer with big loads of less than 5mph ..in these conditions your in negative momentum ..you are trying to rip the earth apart 2ft under the ground ....there no better load training on earth ...or when your going up a hill with 500 bushels of corn and out of 20 gears to use ..your in the lowest one ...in these conditions throttle control is everything even your life is in the balance ... in these condition you can kill the motor and yourself by adding throttle .....and this is probably the biggest reason ive never had a ping out of hooch ....my throttle control is second to no one ...bikes dont come close to being a challenge for ...plus the fact hooch runs really well.....

my point is throttle control and gearing are the biggest factors here in load and timing 3rd down the ladder ....but to have switchable curves on the fly like we are talking here is new territory completely being paved right here on CGW forum ....THIS IS HUGE GUYS.... :thanks: to all involved ....

the comments brian made on his trip last summer on the curves switching was all the proof i needed to see the advantages ...as brians bike is stock carb and all ...and i have seen myself he knows how to load it :smilie_happy:

 

[dan filipi]

Everyone including Joe needs to know that I'm intentionally loading mine beyond what it should be for this set up to get the readings.
Ping (detonation) is tough on the engine but being smart about it, I can get the readings we need to make this ignition perform even better.

 

[joedrum]

:thanks: dan......yes i kind of figured that after going over thread this morning

 

[wilcoy02]

I am starting to know what you are talking about.
I am getting educated.

Thanks Teach!!

 

[C5Performance]

wilcoy02 » Mon Dec 15, 2014 12:43 pm[/url]":28h135ey]
I am starting to know what you are talking about.
I am getting educated.

Thanks Teach!!

Thank you for allowing me to use your trip as an example. I want to keep this simple at first. There is much to learn, and every week I get emails from all over the world. People want to change or build timing curves but they don't even understand what "timing" really means.

This forum is a great place to begin teaching people about the relationship between timing and performance/efficiency/reliability.

 

[dan filipi]

C5Performance » Mon Dec 15, 2014 10:32 am[/url]":2nhaz4if]

wilcoy02 » Mon Dec 15, 2014 12:43 pm[/url]":2nhaz4if]
I am starting to know what you are talking about.
I am getting educated.

Thanks Teach!!

Thank you for allowing me to use your trip as an example. I want to keep this simple at first. There is much to learn, and every week I get emails from all over the world. People want to change or build timing curves but they don't even understand what "timing" really means.

This forum is a great place to begin teaching people about the relationship between timing and performance/efficiency/reliability.

Feel free to link others to this thread.
There is no need to make an account to read the posts.

 

[C5Performance]

dan filipi » Mon Dec 15, 2014 2:12 pm[/url]":1apzmrk8]

C5Performance » Mon Dec 15, 2014 10:32 am[/url]":1apzmrk8]

wilcoy02 » Mon Dec 15, 2014 12:43 pm[/url]":1apzmrk8]
I am starting to know what you are talking about.
I am getting educated.

Thanks Teach!!

Thank you for allowing me to use your trip as an example. I want to keep this simple at first. There is much to learn, and every week I get emails from all over the world. People want to change or build timing curves but they don't even understand what "timing" really means.

This forum is a great place to begin teaching people about the relationship between timing and performance/efficiency/reliability.

Feel free to link others to this thread.
There is no need to make an account to read the posts.

Great idea! Thanks Dan. I want to discuss this very thing with my Facebook followers. I shall send them here

 

[C5Performance]

To keep from confusing everyone, I will continue using the chart we just used to explain timing.

We determined that climbing a steady grade with a loaded vehicle was increasing the EFFICIENCY of the engine.
We also know that (for example) Wes is not going to run his fully loaded Goldwing up a steep grade until the rpm has dropped to a high idle. I don't care how much you retard the timing advance there are certain limitations.

For teaching purposes I have decided that Wes can run his bike down to about 3,000 rpm before he'd downshift to a lower gear.

Then it would make sense that our timing curve (a program telling the coil when to turn off) only has to reduce timing at higher engine rpm (his operating rpm range on the highway). That is the range of engine speeds that Wes would most likely use to climb out of the river valley.

For those of you already familiar with the curves we use, you will notice that as you change from curve to curve, only the "top half" of the curve changes. Why? Because if you came to a stop, your timing curve at lower rpm would not need to be different. If a deer ran out in front of Wes, and he skidded to a stop, his engine would not be under a LOAD at idle, so his timing requirements would remain unchanged from the original timing curve (lets call it curve #1).

Did I confuse everyone yet?

 

[ekvh]

Okay, slow kid in the back here. What does the red line represent?

 

[C5Performance]

ekvh » Mon Dec 15, 2014 10:14 pm[/url]":gnro65xn]
Okay, slow kid in the back here. What does the red line represent?

I placed it way up there so nobody would ask about it.
The red line is where the coil turns on. That is NOT where its supposed to be...just making that clear.
If you look at Dan's picture early in this post you can see where the normal setting is.
Thanks for asking...now I know there are a few people watching :yahoo:

 

[slabghost]

I'm watching and so far following rather easily.

 

[toytender01]

OK I will post my one and only thought on this topic. Back in the model, so manual A ford days you had a manual spark advance lever you had to play with as you drove. It seams to have taken a long time to automate the process. I am 75 and have no time for reinventing things, I only have time for riding. When I was younger I played with electronics and software until I retired. then I went into plumbing and, handyman stuff. Now I hunt fish and RV and visit Great Grand kids. Just had a brain scan, and they said I still have one still in good shape so I use my gray matter to just maintain the equipment I have. You guy's I'll be rooting for you, go. Off to more interesting things
to me opcorn: opcorn: :smilie_happy: :smilie_happy: :music2: :music2: