Ignition coils and Boosters

[dlaing]

What are the available options for ignition boosters and coils?

My manual says the coils are Inductive, but Moto Guzzi's web site says the ignition is CDI. Is CDI only for newer bikes? What gives?

And what is the primary resistance of the coils? 3 or 5 ohms?

thx in advance

[callison]

CDI ignitions essentiallycharge up a capacitor to 200-400 volts and then dumps it into the coil with a very fast risetime. Just like the strobe on a camera. Since the Guzzi has +12 volts across the coils at all times, their ignition only counts as a pointless induction (Kettering) system. The risetime of a transistor switch is better than points, but nothing to write home about.

[jtucker]

Check this out:

 

Evoluzione ignition apmpifier

 

I don't have any firsthand experience with it, but it looks interesting...

[callison]

I'd take this one with a grain of salt. First, upping the voltage will help - that's a given. That will also up the current too but there is no way to "feed more current" to the ignition coil. The dwell time is sufficient at any rpm that a Guzzi engine turns that the coil will saturate as it is supposed to. You can't feed it additional energy based on rpm because it can't use it. Second, it's states it is for 2000-2002 models. All Guzzi ignitions are sufficiently similar that it ought to work with any electronic ignition. Third, this thing was offered up two years ago as a solution to everything under the sun, boosted the electronics package input to around 27V, which is right where the ECU starts to fry, and then it disappeared for nearly a year after people pointed out that it would probably do damage to the computer. Now it's back at a reduced voltage. Before I would shell out this kind of money for a DC-DC converter, I would buy a real cdi unit and hook that to the coils. Now before it sounds like I'm going entirely negative on the unit, I will say that if it were set to just prevent voltage sag to the electronics at low rpms when the alternator is anemic, it would not be a bad thing. Given that Moto Guzzis have universally poor grounding in their wiring, adding a product that boosts the voltage just reduces the saftey margin on some very expensive electronics. Your choice.

 

If you're interested in the travails of "rolling your own" EFI, check out http://www.jefferies-au.org/My16M/index.htm. Cliff Jeffries in Australia did just that (and is still doing that - it isn't easy) and his observations on the Marelli electronics and his own progress makes for interesting reading.

[jtucker]

Pardon my ignorance, but assuming the ignition system is inductive, does this impact what coils can be used? I've looked at info for a number of aftermarket coils, but none state whether they are CDI or inductive? If there is a difference between a CDI coil and an inductive coil, how can you tell?

[emry]

The resistances should be very different. (Don't remember what of the top of my head though.) Standard coils use a constant 12V while a CDI unit will use much higher voltages, normally several hundred. Remember that the total wattage of the coils is very close between the two type. So using Ohm's law the resistance of the CDI style (high voltage) must have a higher resistance or it would flow too much current and burn your fuse or CDI unit. I actually made that mistake on a 900 Ninja when I was young, burned up three ICU's before I figured it out. If you are going to replace your coils make sure that the resistances of the new ones are very close to the OEM, ECU's are expensive.

[jtucker]

So, in a nutshell, as long as the primary resistance of the replacement coils matches up with the original coil, I'm OK? That's sort of what I was thinking, but I'm just trying to confirm before I end up frying something...

[callison]

There's a whole lot of knowledge on these substitute coils at http://www.b2g3.com/boards/board.cgi?&user=wildguzzi, try posting your question there.

[Cliff]

I don't think CDI or anything else fancy will benefit us. Our demands on the coils are quite low.

 

CDI is more important on cars where a single coil is sparking all the cylinders.

 

A bit of theory. When the points close the current through the coil is zero. The current increases in a exponential manner ( 1 - e^-t) because the coil is basically an inductor. To get a reasonable spark this current needs to increase to a certain level and this will take a certain amount of time - around 2ms.

 

Even at 10000 RPM ( 12 ms cycle time ), there is plenty of time to charge the coil.

[dlaing]

from Topica in January,I guess they were discussing a problem.

From: Carl Allison

clip

So... Has anyone with a spine frame or late model EFI bike put on

higher output/better coils? If so, what were the results? clip

 

Wayne O. replied: clip

As for changing the coils, anything with a lower resistance risks toasting

the ECU. Anything higher probably wouldn't have the same output. And since

there are two coils, the dwell angle SHOULD be huge for a powerful output as

is (but then the programmer controls that). And there is plenty of spark

when cranking the motor over so I can't see it being the spark.

 

So, it appears that trying to UPGRADE would be a waste of money, so I guess if one needs to replace, it is best to use OEM. Too bad, it is fun to think you are getting 30,000 rather than 20,000 Volts if you buy aftermarket coils.

I guess twin plugging is the only way to really boost ignition performance....

Opinions?

[Mike Stewart]

I have talked to Ken at Evoluzione a few times and have purchased some items for my Aprilia Falco. I had talked to him a few weeks ago and he was putting a Lemans on the dyno that day. All I can say is the dyno shows good results with all their products. The ignition amp works very well on the Aprilia's due to their weak coils. I am a firm believer of a hot spark and have thought of putting on a CD unit on my V11S a long time ago. My thought is a CD unit, larger plug gap equals hotter spark and longer spark duration (your results may differ, batteries not included). The main reason for the adjustable fuel regulator is that every fuel system is a little different and by making a way to adjust it will put the system pressure where it is suppost to be. Aprilia's fuel pressure is all over the map and it was impossable to make a fuel map for it without getting the fuel pressure with in specs. first. Anyway, If I ever get my V11S back from the shop, I may be trying some new mods.

 

Mike in Very Wet California

[jtucker]

IThe main reason for the adjustable fuel regulator is that every fuel system is a little different and by making a way to adjust it will put the system pressure where it is suppost to be.  Aprilia's fuel pressure is all over the map and it was impossable to make a fuel map for it without getting the fuel pressure with in specs. first.

I have a sneaking suspition that this may be the case on our Guzzi's as well... I might have to get my hands on one of Ken's pressure gauges just so I can have a looksee at what pressure my bike is really running at. Curious minds want to know...

[ScuRoo]

Hope I’m not waking the dead here - but I do mosey around searching topics sometimes.

It’s a pita just having lots of disparate threads on same/ similar subject so I’d thought it best just to ask my question here after reading this thread.

Am wondering if anyone has any knowledgeable opinion on this product - & whether it has any benefits as an upgrade to our V11’s?

http://www.altmann.haan.de/P1/

[Cliff]

31 minutes ago, ScuRoo said:

Am wondering if anyone has any knowledgeable opinion on this product - & whether it has any benefits as an upgrade to our V11’s?

http://www.altmann.haan.de/P1/

This is for pre-EFI systems. Your ECU has much more control over spark than this can provide.

[ScuRoo]

Ah, I see - the 2019 Indian, 2006 Harley & 2015 R9T have been converted to carbs & done away with their ECU’s.

Okay thanks Cliff for your assistance.