Ironhead Broke Down and Ordered an Ultima Ignition Kit

[bustert]

Originally Posted by joe s View Post
Adding VOES will make the bike run better with lousy gas.

hardie-har-har
the smaller chamber ironhead is more prone to detonation. the voes system forces full advance which will compound the issue. voes is basically an EPA thingy as it has a large effect on emissions. the ultima has a mechanical advance emulator setting.
stock flyweight springs range 1800>2200 rpm. i like the heavier springs that up it to around 2800 rpm.
i run the ultima on my 01 sport and no voes because of my build, had issue with clutch off and mild accel on hot days which neither tune not fuel could resolve.
running less lead helped.

[Jeff]

Well, the kit has arrived and it's been installed. Wonderfully simple and straight forward. I ran out of time to fire it up for a test ride, so that will come tomorrow.

I went ahead and set it up with the #1 advance curve, single fire mode, rev limit at 6,500. It's only static timed right now, per the instructions provided. It says that provides 34 degrees of total advance at 2,500 rpm. Sounds entirely reasonable to me.

I'm hoping I'll get it out tomorrow for a test ride. Weather looks perfect, I've got nothing else planned... but we all know how that goes... I'll report back once I've ridden it enough to have formed some impressions.

[needspeed]

So assuming you timed your bike with the points by the book at 40°. If you feel a power difference with the ultima, its because it's set 6° retarded from what you're used to.

If you think it ran better at 40 then you can advance the ignition plate 6° to get there. If you like the way it runs at 34 then leave it there. It will probably be less prone to detonation.

The Ultima ignition wasn't designed for sportsters. It was intended to be used on Ultima engines, hence the 34° total advance. That's not necessarily a better setting for an iron head, though depending on your personal set up it may run fine there.

[Jeff]

I always ran the total advance on the timing mark at 40 degrees. I have been running the Dyna unit for longer than I can remember. I did set the Ultima per their recommendations under "static timing the motor", but did not start it to check full advance.

I did about an 80 mile loop on it today. Perfect day out for riding, low 70's with low humidity. The bike ran flawlessly. I was kind of surprised, since I never did check dynamic timing, but at this point I really see no reason to do so. The bike has never run so well...

[IronMick]

Originally Posted by Jeff

... I did about an 80 mile loop on it today. Perfect day out for riding, low 70's with low humidity. The bike ran flawlessly. I was kind of surprised, since I never did check dynamic timing, but at this point I really see no reason to do so. The bike has never run so well...

+1

That is what I found on the 3 or 4 IronHeads that I installed these on

[SHAKY DAVE]

Originally Posted by IronMick

No reason to not use the complete Ultima kit

absolutely.the whole kit is great,even the plug wires.over 100,000 miles and still goin great

[bustert]

the trigger led is spot on, never had to adjust one.

[JB in NC]

Originally Posted by PoodlePunche

Even with good ethanol free gas, without VOES my bike ran super hot, since there was essentially no timing advance.

Think i paid around $40 for the VOES sender, so there's really no reason to skip it.

hardest part was finding a place to mount it. Put mine under the seat next to the breakers

Can't let this go by without correction. All of these electronic modules have advance curves built in, and without the VOES, the advance curves are still active. The VOES just modifies the advance curve according to the manifold vacuum (which on a street bike is almost always an advantage). I would say that the VOES offers a function similar to a vacuum advance on an auto distributor, but there are many younger guys that I'm sure have never seen an automotive vacuum advance, let alone know how one works. There are strategies for using these electronic modules without the VOES, sometimes with the VOES signal wire grounded, and sometimes with the signal wire left open. For motors like the ironheads and shovelheads with big, open, lazy chambers, a narrow but steep advance curve is what is needed, as compared to the more gradual curves that the more modern evo chambers need.

In short, without the VOES, you still had an advance curve in operation, but maybe not well chosen for your motor. If the VOES helped you, that's good, but you could probably have tuned the ignition without it. I just want to make that point clear for others reading this thread.

Jim

[Jeff]

Yeah, it's crazy just how much better the bike runs. Color me "jaded", but after playing this game for so, so long, I've seen my share of "miracle cures". I think we probably all have. It idles far better, revs more freely, no oddball transitional or trailing throttle carb farts, etc. etc. I always struggled to get the idle I want, somewhere around 1,050 - 1,100 rpm, but it seemed the mechanical weights must have just been starting to open a bit, and it would "hunt". Now it just sits there at a rock solid, unwavering 1,050. I swear I could fire it up and go back in for breakfast and it would still be doing it.

Anyway, I've joined the club. I wish I would have listened a couple of, say, decades ago. I have to say, this is a real, very tangible improvement. Anyone who has not yet switched is missing out. I sure was...

[brucstoudt]

makes me wonder how much better it might be if it was designed for a 40 degree timing motor like an ironhead?