SUGO CDI for Borut... (ignition curves)

[41juergen]

Jools, I don't need the flywheel as I tested the 4DP with both (the matching one as well with my smaller diameter 4DP or 5KE flywheel) and got the data same as shown in the excel file.
Not sure what you mean with needing the controller? Normally the PV control is a part of the CDI's, at least all I saw before. I have a PV motor connected into the loom and got the PV data out of all the CDI's....
cheers
Juergen

[jools]

Juergen

I'll send you photos & cct diagram to explain. It has discrete looms for connection. It does include PV controller, my  mistake I though it was like the 2ma/1kt arrangement.

cct diagram attached below

[41juergen]

Perfect, yes I see. I double checked that yesterday by myself too and found that wiring diagram...  But is the CDI connector itself the same as on the 3XV / 4DP ones?

[maccas]

Juergen,

One quick question.

4dp flywheel vs the one you have used for all other testing.

To get the initial 21 degrees on the ignition curve, did you have to adjust the stator backing plate after changing flywheels? If you did, then that is the point I am trying to make.

Dan

[jools]

Perfect, yes I see. I double checked that yesterday by myself too and found that wiring diagram...  But is the CDI connector itself the same as on the 3XV / 4DP ones?

No they are individual plugs as shown in the diagram.

Let me know if you still wish to test them 

[41juergen]

Dan, when using the different rotors I also needed to change the plates (as the diameter was different and so also the distance of the pickups to the flywheel was different). But as said I used the Zeel to set the starting point with the 20°CA flat curve (what you normally use to check the base advance) and than tested the different CDI's. So that's the reason I believe the different flywheels have no impact?
BTW: the Zeel uses only the front lobe whilst e.g. 1 cylinder engines typically use the rear for idle and the front in the higher revs, most of 2 cylinder and / or racing engines only use the front lobe (that was the feedback I got from Borut).

Jools, yes I would be still very interested to test them. This also to get all data and to give every body the opportunity to use a programmable CDI if wanted...

cheers
Juergen

[maccas]

Ok got you. I'll reply properly at lunch :-)

Dan

[maccas]

Ok, so you use the zeeltronic to get the front of the lobe on each flywheel in the same place for each test. Correct?

That means that regardless of the CDI you test, each curve will be relative to each other. So 4DP would have "x" degrees more advance compared to say 3xv-9A, when one type of flywheel is used. I totally get that and I think that is a good comparison. You have taken the back of the lobe (initial timing calculation) out of the equation 

But by doing what you've done, we don't know what the "absolute" ignition curve is for each CDI tested.

I'll try to explain...

OEM cdi uses the back of the lobe for starting and idle. Once above say 2000rpm the front of the lobe takes over and the ignition timing calculations are based on the "static angle/advance (front of lobe)" - "x" degrees to give the programmed ignition advance.

Taking the 4DP 93 model as an example, the back of the lobe is 18 degrees BTDC. The workshop manual denotes setting the ignition timing to this figure. This means that the back of the lobe will be in the centre of the pick up at 18 degrees BTDC for each cylinder.

The ignition advance curve is then determined by the relative position of the front of the lobe, to the back of the lobe. For arguments sake lets say front of lobe is 60 degrees BTDC.

If you set up your machine with the 4DP-10 flywheel such that the initial advance is 21 degrees, then the front of the lobe is 63 degrees BTDC. Which means the ignition curve is advanced by 3 degrees compared to how Yamaha tell you to set the ignition timing in the workshop manual.

And surely the " out of the factory" ignition timing is what we are trying to determine?

If I need to explain more just say.

Dan

[41juergen]

So it looks like that you are correct!  As I'm a mechanical engineer all the electronics stuff is very thin ice for me....
I had a chat with Borut about that and his feedback was that he believes that also the 3XV CDI uses the rear lobe for starting / idling. That would mean to determine the correct values in the higher revs we would need to double check if the e.g. 28°CA timing for the 4DP2 is correct via checking it with a strobe lamp on real bike, right? With that we would be sure that the timing curve should be correct up to max. speed whereas the idling would be not too important.
But during writing that following came up my mind: when using the Zeel to calibrate the 4DP2 rotor and stator plate on the test rig that should give the correct position compared to a 4DP engine, right? So than checking the 4DP2 CDI should give the correct data. When doing that for a 3XV CDI I would also need to use the 3XV rotor with pick-up's. The same if I would test a 4DP CDI which had the smaller diameter rotor of the 4DP3... That all only if the °CA length of the lobe is different between the rotors...

That makes collaboration between people so successful, what one don't know others can fill up... thank's for helping me Dan!

[maccas]

No problem! Don't worry, you don't need to run a bike, you can do it all with your test machine and use the zeeltronic to set it up for the 3xv cdi's.

I'll write more at lunch...

Dan

[maccas]

Juergen,

I have made a mistake. The 3 degrees thing I said is wrong! It may be that the ignition curve you have quoted for the 4DP is correct, it may also be not quite right!

This is because we have another variable at play! The adjustable pick ups 

I think what you need to do for the 4DP is this:

1. Set up your machine with 4DP cdi, flywheel, stator.

2. Have machine running at 1000rpm.

3. Adjust pick ups so that spark plug is firing at 18 degrees BTDC.

4. Measure ignition curve across rev range.

This way, we know that each pick up is mounted precisely at TDC for each cylinder. For the 3xv it is straight forward as the pick ups are fixed and cannot be moved.

I suggest you do the same for your other smaller flywheel, but instead of 18 degrees BTDC. Use 22 degrees BTDC (figure from 5KE workshop manual). Then we know that you have the front of the lobe on the flywheel in the right place for that type of flywheel.

You can then fit the zeel, and using the 20 degree flat curve, calculate the static angle for that flywheel. Whatever the difference is between that and the static angle of the 3xv (65 degrees), allows you to correct your 3xv curves without testing them all again.

For example, say you calculate that the static angle of the 5KE flywheel is 64 degrees. This means you'd need to add 1 degree to all 3xv curves, they'd then be correct  . The only part of the curve that may be wrong is the idle part, as that depends on what type of 3xv flywheel is fitted (i.e. some have the back of the lobe at 10 degrees BTDC, some have 21 degrees BTDC). Idle/ starting doesn't matter anyway, as long as the figure provides acceptable idling and starting.

Dan

I hope that makes sense, this is a lot more complicated than it first appears.

[maccas]

Juergen,

Had another think. When you tested 3xv cdi's with small flywheel you set the initial part of the curve to 21 degrees by adjusting the backing plate/ pick ups correct?

Dan

[41juergen]

Dan,
I didn't worked with adjusting the pick-up plate. My "main" assumption was that the idle timing will be defined also by the front lobe (so independent from the flywheel lobe spec) which may be was wrong... Based on that I made all tests. Today I use the Zeel to "calibrate" the ignition timing needle as per Borut's answer we know that he uses the front lobe for all rev's.

When I tested first time the 3XV CDI's I set the ignition timing during idle (approx. 1300 rpm) to 21°CA as shown in the 3XV1/2 manual (see attached "timing needle" at the degree wheel). Of course this procedures is finally the same like adjusting the pick-up's via the plate.
Luckily I did that with the 3XV-10 CDI of the 3XV2 as the small TZ flywheel has the same lobe starting and ending CA position as the related 3XV1/2 flywheel. So at least these 3XV-10 and 3XV-00 data should be correct (as both use the same flywheel spec and idling timing as shown in the manual).

Yesterday I measured again the 3 different flywheels I have: the 3XV1/2, the 3XV4/6/9 and the TZ250 small diameter one. The starting point of the lobe relative to the cut out to fit the half moon in the notch at the crank is all the same. The CA duration of the lobes is for the 3XV4 flywheel a bit longer than for the 3XV1 and the TZ. The last both one have exactly the same starting and end point of the lobe with an overall 45°CA duration, the 3XV4 flywheel has the same starting point but a longer lobe with an overall duration of 52°CA.
The longer 3XV4/6/9 lobe should theoretically go along with the different ignition timing at idle for the 3XV4/6/9 (10°CA BTDC as shown in the manual). But from the data I have it's not the case. So first I will verify this evening again the data of the 3XV-00 / -10 CDI with the small flywheel against the current data. Let's see...

That's really confusing, I would prefer to verify the ignition timing at let's say 3500 rpm with a strobe lamp on a stock bike. Unfortunately my bike is not running yet...
Juergen

[Warwick]

I don't know if it's helpful here, but I can confirm that when I used to run a TZ/SP set-up many years ago, the 4DP-10 ignition seemed to work fine using the 91SP rotor and pickups (and loom) in use. I never measured the timing, but with a very safe set-up for road fuel (modified TZ heads to give a safe rather than optimised head volume) it gave a fair powercurve, with a peak at around 11,500rpm with fair over-rev. This would lead me to believe that the ignition timing couldn't have been far from what it should have been?

[jools]

Reading this with interest..........

Juergen - do you need the stator and rotor with the CDI's ?
I also have the loom I can send too.

(did you pm me your address ??)

Jools