How does an ignition advancer work?

[cozy]

I installed a V&H ignition advancer this weekend. Low end performance is greatly improved. So what's going on behind the scenes?
Thanks !

[glenn9171]

Basically the little tab on the advancer contacts (or comes very close to actually touching) an electrode when it spins.  This conducts the electricity to make the spark plugs produce the spark that burns the fuel.  The advancer does just like the name implies...makes the spark happen slightly sooner than it normally would.  The tab on the advancer is set a few degrees ahead of where it would be on the original piece.  So it reaches the contact point a little sooner, thus making the fuel/air burn in a more efficient moment in the cylinder's travel.

[Frost]

then why don't suzuki make it stock?...isn't it better efficiency that way?

[octane]

then why don't suzuki make it stock?...isn't it better efficiency that way?

More low end power, but not necessarily as efficient. My hunch on why it's not stock is it probably alters emissions enough that Suzuki retards the timing slightly to satisfy the EPA. Same logic behind the bikes being jetted lean at the factory. WIth lower octane gas, advanced timing can also cause detonation in the cylinder, though I often run 87 in my GS and have never had that problem with the 5 degree advance.

Putting the advancer on the bike is the same principle as bumping the timing up a few degrees in your car.

[suzukimad]

Can there be any problems,if you rejet,and also have  v&n advanced
ignition,?.


                              Tony

[dgyver]

The only real problem is you may not pass an emissions test.

[Rema1000]

Curious why emissions would be worse.  From my limited knowledge, advancing the spark will actually provide a more-complete burn (hence less unburnt fuel in the exhaust), up until the point where preignition occurs.  So retarded timing would be more-forgiving of low-octane fuel, at the expense of both power AND emissions.  I'd expect that an earlier, fatter spark (and preferably multispark) would actually help reduce emissions, while improving power.

[The Buddha]

OK From what KevinC told me few months ago...
The little rotor's tab fly's by the little square doo hickey, and that tells it what the rpm is, and that makes the spark get advanced by the black box. Also the location of the thing sets a minimum advance... By moving the tab forward in the direction of rotation you have advanced the spark a few degrees, the tab being smaller makes the black box think the engine is running a higher rpm and hence it acheives the advanced spark... effectively its advanced to 17 degrees minimum, and it achieves the 36 degree advance at maybe 3000 revs instead of 4000.... And the jetting has to be richened to keep it from knocking with the higher advance, and that makes it less clean at the 3500 or so where they check emissions.
Cool.
Srinath.

[suzukimad]

So with the av/ignition..k&N air filter (not pods)
And motad nexxus,replacement exhaust system (not race)

Uk 1997 model...

it`s fine for 127.5 main jets,lift needle 1 clip.
and set mix to 3 out..

Not making it lean,?....


                                Tony

[goggleman]

Where did you get the advancer? I've been lookin but so far do dice...  

[Kerry]

Where did you get the advancer? I've been lookin but so far do dice...  

To have your stock unit "advanced", see the thread Ignition Advancer Exchange?.

Alternately, you could try the (reversible) Do It Yourself Timing Advance mod as documented right here on GStwin.com!

[GRU]

i advanced my timing a month ago and my bike didn't run right on the freeway so i just undid it to the stock possition and works a little better now  :dunno:

[goggleman]

Thanks Kerry. Is that offer still good for anyone?

[Rema1000]

OK From what KevinC told me few months ago...
The little rotor's tab fly's by the little square doo hickey, and that tells it what the rpm is, and that makes the spark get advanced by the black box. Also the location of the thing sets a minimum advance...

I tried to figure that out, but I don't see how the Black Box can figure-out when the spark actually happened.  I think that the 5 degree rotation of the rotor will provide an across-the-board advance.  The Black Box will provide additional advance in proportion to the RPMs.  So my thought is that the maximum advance would end 5 degrees higher  (at 4kRPM) with the mod, than without the mod.  Of course, 5 degrees of extra advance makes much less difference if the Black Box is adding another 30 on top of that.  

If anyone knows of a detonation sensor connected to the Black Box, then that would prove me wrong.  Also, I plan to test my theory once I get my workshop back (just moved, and currently can't even find a toothbrush, much less a timing gun!).

It's interesting to hear that they test the emissions at 3500rpm.  Is that with load (maybe while on a dyno?), or no load?

[Kerry]

Thanks Kerry. Is that offer still good for anyone?

The best way to find out is to PM and/or email Bob Broussard himself.

I would be surprised if the offer's not still current.  I believe Bob asks for $5 to cover shipping and some fraction of his time & effort.

[glenn9171]

GRU, if yours didn't run right on the highway, maybe you advanced it too far?  It doesn't take much at all to get the wanted results.   :dunno:

[The Buddha]

OK From what KevinC told me few months ago...
The little rotor's tab fly's by the little square doo hickey, and that tells it what the rpm is, and that makes the spark get advanced by the black box. Also the location of the thing sets a minimum advance...

I tried to figure that out, but I don't see how the Black Box can figure-out when the spark actually happened.  I think that the 5 degree rotation of the rotor will provide an across-the-board advance.  The Black Box will provide additional advance in proportion to the RPMs.  So my thought is that the maximum advance would end 5 degrees higher  (at 4kRPM) with the mod, than without the mod.  Of course, 5 degrees of extra advance makes much less difference if the Black Box is adding another 30 on top of that.  

If anyone knows of a detonation sensor connected to the Black Box, then that would prove me wrong.  Also, I plan to test my theory once I get my workshop back (just moved, and currently can't even find a toothbrush, much less a timing gun!).

It's interesting to hear that they test the emissions at 3500rpm.  Is that with load (maybe while on a dyno?), or no load?

The black box is directly related to rpm...it also does the next spark based on dwell, in a sense, the present dwell, determines the next spark... which is why the tab's location doesn't count, only the size of the tab does... I think... would some electrical guru answer this please. KeviC will be the best, cos he told me before. It made sense too... but I forget the exact phrases...
Cool.
Srinath.