C5, PowerArc, and the mystery of Timing

Gary,

We notice faster starting and smoother idle on the videos, yet my old Magneto powered Hercules engine starts hard even though a mag puts out awesome spark.

Why does a PowerArc ignition help low rpm operation, and a follow up question...

How do you determine a spark curve? Isn't it all based on rpm, so the curve should just be a straight line starting at 10 and ending at 35, so when i want more power i just raise the total advance higher than before?

opcorn:

I'm also wondering how the advance curve is figured, since you no longer have a mechanical/vacuum advance mechanism, nor are there any other sensors involved, such as baro/map, knock, or throttle input(tps). Are we dealing with space alien technology here? :smilie_happy:
Just kiddin aboot the last part, but I am curious aboot how the advance is programed....especially since I tend to get a lot of ping under load in 100 deg temps, regardless of the fuel quality...

opcorn: :read:

[url=https://www.classicgoldwings.com/forum/viewtopic.php?p=95636#p95636:2szktl05 said:

C5Performance » Tue Sep 10, 2013 8:10 am[/url]":2szktl05]
Isn't it all based on rpm, so the curve should just be a straight line starting at 10 and ending at 35,

Click to expand...

Sorry...it can't be helped, but....if it is a straight line, then it can't be a curve(except in Utah).... :smilie_happy: :hihihi:

oh boy :smilie_happy: :doh:

More opcorn:

opcorn: :beg: :thanks:

As far as I know you will never get a better timing curve bike then when it is new, The springs are new, the advance weights lubed up and clean and the engine is pulling the right amount of vacuum. The vacuum advance mechanism is fresh and clean and generally everthing is right on.
You can get a better curve using an adjustable timing light working down from TDC to time it instead of hoping your multiple mechanisms are all working properly and in the case of the GL together when they should.

[url=https://www.classicgoldwings.com/forum/viewtopic.php?p=95654#p95654:3cdwr58e said:

AApple » Tue Sep 10, 2013 9:31 am[/url]":3cdwr58e]
I'm also wondering how the advance curve is figured, since you no longer have a mechanical/vacuum advance mechanism, nor are there any other sensors involved, such as baro/map, knock, or throttle input(tps). Are we dealing with space alien technology here? :smilie_happy:
Just kiddin aboot the last part, but I am curious aboot how the advance is programed....especially since I tend to get a lot of ping under load in 100 deg temps, regardless of the fuel quality...

Click to expand...

Well what hasn't been explained completely in simple terms is the benefits the C5 ignition brings to the table.

What Gary from PowerArc informed me of in a phone call is the C5 has the capability of selecting retarded curves, 3 of them.
The benefit this brings is we can select retarded curves to compensate for these conditions, like pinging, bad gas, heavy loads etc.
I've asked Paul to post the 4 selectable advance curves so we can see the differences in them as they come, pre-programmed.

I had mine set for the most retarded curve at first. That's also what it was set for in the video I took.

It ran better than it ever had.
I changed it to most advance, which matches the stock advance curve and it was a totally different beast.
It would rev almost instantly to full rpm with NO spit or pop and accelerated out on the road as fast or faster than it ever has.

As I showed in the video, the idle increased.
This tells me there's firing going on where there wasn't before telling me something good is happening.

It's a good system.
I'm looking forward to when I get the flodding #2 carb changed!

I think we all have a really cool ignition system available to us now.
The possibilities are open to us for other things that were impossible before.

So...what I see is that the C5 system has pre-programed advance curves, that will advance/retard the same, regardless of engine load. Totally engine RPM dependent. I gotta say, someone knows what the heck they're doing in the programing department, if this is true, considering the rave reviews from Dan, and Joe. We have yet to see how the set-up will work in 100+ degree temps in traffic, or 40 degree temps in the winter, but I gotta say..it all looks VERY promising! The ONLY problem I have is....I cain't afford it! :crying: :crying:
I sure like the whole concept, and the major improvements it provides. :clapping:

I haven't posted much information about the details of curves, selectors, and specific technology for three reasons.
First, i just joined the forum and i'd like to contribute in other ways than just ignitions.
Second, introducing a new product to forums tends to bring out the "that'll never work" crowd, and i dont care to argue on every post about why i believe optics are better than Hall Effect sensors.
Lastly, i have been cruising MSD and Dyna's websites to find out how their systems work. There isnt any info about it. Our website has 10 times the information already. Although i am not sure how many of you have cruised our site yet. This is why i started this thread...to begin a question and answer area for more specific topics.


To answer one question right away, you can control the C5 using engine vacuum if you wish. There are two sensors on the GL system. They can be triggered by toggle switch, rotary switch, vacuum sensor (like a Harley), or a MAP sensor. I have not shipped any kits with vacuum or MAP sensors yet but we are working on a kit. By providing feedback to the system, it can change curves as needed, or using the rotary switch you could decide when to change curves.

If you could get it to dump that waste spark and be a single spark system, I'll bet you sell a few to the turbo/supercharger crowd and it would grow from there.

[url=https://www.classicgoldwings.com/forum/viewtopic.php?p=95654#p95654:fq391ghv said:

AApple » Tue Sep 10, 2013 11:31 am[/url]":fq391ghv]
I'm also wondering how the advance curve is figured, since you no longer have a mechanical/vacuum advance mechanism, nor are there any other sensors involved, such as baro/map, knock, or throttle input(tps). Are we dealing with space alien technology here? :smilie_happy:
Just kiddin aboot the last part, but I am curious aboot how the advance is programed....especially since I tend to get a lot of ping under load in 100 deg temps, regardless of the fuel quality...

opcorn: :read:

[url=https://www.classicgoldwings.com/forum/viewtopic.php?p=95636#p95636:fq391ghv said:

C5Performance » Tue Sep 10, 2013 8:10 am[/url]":fq391ghv]
Isn't it all based on rpm, so the curve should just be a straight line starting at 10 and ending at 35,

Click to expand...

Sorry...it can't be helped, but....if it is a straight line, then it can't be a curve(except in Utah).... :smilie_happy: :hihihi:

Click to expand...

To answer the first question as best i can:

There are a few levels of change when dealing with advance curves. I will try to explain in basic terms.

Magneto: These are set at one place. You can retard them to get the engine running, but they operate at ONE setting.

Points/Triggers: Points operate on rpm only using weights and springs. GL1000 is an example. Triggers like the GL1100 use a vacuum advance to fine tune timing based on "load". When you go up a steep hill, you open the throttle, the vacuum drops, and the advancer allows the timing to drop back down (less advance).

Sensors/Mapping: Some ignitions sense vacuum (Harley), some use a digital sensor (MAP sensor) and I will use Yamaha as an example...they had 3D mapping. It used engine rpm, throttle position, and vacuum to determine where to place timing.

You can run the PowerArc system using straight up timing like a Magneto, or with a vacuum sensor like a Harley, or even use a MAP sensor that converts a vacuum signal to digital and uses voltage changes to control curves.

One thing to remember...with a mag you have NO adjustment. With all points systems you have only the weight of the arms, and hopefully the accuracy of the springs, and with your vacuum system, as Dan stated (his leaked) you had a crude rotating bearing and small plunger to adjust your timing. Even if you never used any vacuum input to adjust your curve, you will still see a significant improvement in performance and efficiency simply from having electronics control your curve, and dont forget the multiple spark advantages.

I want to explain timing in the next reply, before i get into multi sparking, if thats ok with you guys :thanks:

I would like to explain a few things about timing curves. There are things i will leave out, but for those new to ignitions and tuning, i want to keep it simple.

What is a timing curve?

When an piston is moving up the cylinder towards the highest point of its travel (TDC=Top Dead Center) the coil must be turned off so the spark plug ignites the fuel. We need to "time" the two events for proper fuel burn and maximum power (efficiency).

When a piston is moving slow, the amount of time needed for electricity to travel from the coil to sparkplug is much different than when the piston is moving fast.

NOTE***

When talking about the time it takes, we do not use TIME on a clock. Instead we use DEGREES of engine rotation before the piston reaches the top. Remember this point. Please let me know if you are confused. Everything I will be discussing is going to make more sense if you understand this statement.

So a timing curve is a method of showing the amount of timing advance versus the engine's rpm at that point.
Next I will discuss why most four stroke engines have the same curve.

[url=https://www.classicgoldwings.com/forum/viewtopic.php?p=95707#p95707:1ul92lh5 said:

ekvh » Tue Sep 10, 2013 10:25 pm[/url]":1ul92lh5]
If you could get it to dump that waste spark and be a single spark system, I'll bet you sell a few to the turbo/supercharger crowd and it would grow from there.

Click to expand...

In many cases we can program the ignition to single fire the coil, but turbo/supercharging has little to do with it. We single fire Harleys to avoid the "wasted spark" cylinder from igniting incoming fuel. The angle of the "V" comes into play.

The use of turbos or superchargers bring new hurdles into the spark management game. I won't explain that yet, but you are correct...these ignitions have been used for those applications for years. I will be installing our first automotive system on a supercharged big block Chevy in a week or two. I will post the video!

so on this system do I have to choose which curve to run my bike or does it automatically choose the best one?

[url=https://www.classicgoldwings.com/forum/viewtopic.php?p=95713#p95713:df9jrevo said:

wilcoy02 » Tue Sep 10, 2013 11:40 pm[/url]":df9jrevo]
so on this system do I have to choose which curve to run my bike or does it automatically choose the best one?

Click to expand...

Without adding a vacuum sensor, your bike will remain in the standard curve. If you wish to install a sensor to retard timing on demand, we can help you install a rotary switch or install a VOES or MAP sensor in the future. I'm working on a kit but haven't had time to finish it.
I have built two rotary switches so the rider can change curves, but seriously, are you really going to do that while riding?

These bikes run so strong compared to stock you probably wont need a switch, BUT....like most guys, we love have control, right?
That's why at some point we will have a kit.

Getting to why engines have the same basic curve:

Take a CBR1000RR race bike and compare to a Trail 70. Do they have the same curve? YES
Do they have the same horsepower? NO

How can they share the same curve?
Ask yourself this question....

Does electricity travel faster on a CBR1000? NO
Do they both use pump gasoline? YES
Do they both idle around 1,000 rpm and end up over 5,000 rpm? YES

So why would they use a different curve? "well the CBR has more power and goes faster"
Remember, the engineers have designed the transmissions so gearing matches the horsepower of the engine.

The only difference would be an outside force such as HILLS, WEIGHT OF RIDERS, FUEL OCTANE which means the load can change.
All things being equal, the timing requirements of most engines are virtually identical. We retard the timing only when the external load changes the rate of fuel burn.

Make sense?

You have to choose unless you have the vacuum advance that converts to electronic signal hooked up. Which so far is not an option as I understand it to this point.
Dang 1:30 am and I still get beat to the answer! :head bang: :smilie_happy:

[url=https://www.classicgoldwings.com/forum/viewtopic.php?p=95717#p95717:un8ejugh said:

slabghost » Wed Sep 11, 2013 12:28 am[/url]":un8ejugh]
You have to choose unless you have the vacuum advance that converts to electronic signal hooked up. Which so far is not an option as I understand it to this point.
Dang 1:30 am and I still get beat to the answer! :head bang: :smilie_happy:

Click to expand...

I have the advantage of working all hours of the day and night. Sorry i beat you

You have the option right now of using a VOES switch. Your ignition is wired for two separate inputs already.

To clarify what i stated earlier, I am working on using a MAP sensor to switch curves. This would convert a vacuum signal to a voltage reading. Once that reading is compared to a "reference voltage" the ignition could be set to change curves at two predetermined points. Many Harley Davidsons came with a vacuum sensor from the factor and our ignition hooks right up!

I don't have any of my own cycles equipped to change curves on the fly.

1) GL1000's never had a vacuum advance, nor did any other muscle bike such as my CB750 or the awesome Kawasaki Z1
2) Vehicles run so strong after an ignition upgrade, i don't really think it's necessary

I do however, feel that many customers will want that feature, and i will be installing a MAP sensor on my Wing once the sidecar is done. If you wish to install a vacuum sensor, give me a shout and we'll help you out!

Wes, it's unlikely the curve will need to be changed normally.
As I see it the changes would be needed only under extreme conditions but even at that,

My first ride with it in it was about 100 degrees and I was riding it hard.
I didn't have the radiator deflectors on and engine temp was running about 3/4, much higher than it should be.

I got on a stretch of freeway I could hear and feel the engine better.
It's a uphill grade and even at those extreme conditions it didn't ping on regular gas.