Larger coil options

[dgyver]

Anyone know of any larger/higher capacity coils that can be used on the GS?

I have seen some used from another manufacturer, Honda I think, but can not remember which model.

[Dragonfly]

Your refering to ingiton coils right??
I was thinking the same thing this afternoon.
Its always nice to have a little hotter spark.

[Rema1000]

I'd be interested in that.  I have read that increased "power" or wattage of the coils increases the duration of the spark (...but isn't that what the "dwell" on the rotor determines?).

Anyways, I could probably benefit by a fatter, longer spark.  MSD has some replacement coils; but I wonder what would happen just using a larger coil (say, from a car).

[werase643]

why don't you just go the dual plug route.....

[davipu]

and a 4 valve per cyl. head......

[Rema1000]

Hrm, was just reading http://toyotaperformance.com/ign_combust.htm .  According to that page, the length of the spark is a function of the inductance of the coil (and isn't that related to number of windings?).  Multispark is claimed to not be useful above 3k RPM due to timing issues.

Also, it sounds like unless you're getting misfires (such as due to increased compression), changes to the ignition system are probably wasted.

[dgyver]

I needed to replace the spark plugs in my truck. So I had been reading some of the theory behind setting the gap and size of spark in relation to power, fuel burn, etc. Really more interested in using coils from another bike, say a v-twin, like a TLR since I happen to have one. Have not had a chance to look at them or the wiring diagrams yet.

I have thought about dual plugs but the available area is very limited and not sure if a second plug will fit.

There is another modification that I have been looking into that does go along with larger/higher capacity ignition coils. This has been done on the TL and gained up 3hp. Basically it is providing a larger direct wire from the battery to the coils, with an inline fuse and relay. There is some voltage loss within the wire harness of the TL. I am sure the GS wire harness has some of the same faults.

Some of the interest that I have is to gain performance without a lot of expensive modification or fabrication.

[werase643]

there is definately room for a second plug
straigh down inboard of the valves

not in the optimum location but two sparks will have a shorter flame propagation.... quicker fuel burn

probably have to retard the timing for this mod..... :dunno:


wow,     the Drunk woke up....definately no room for a second plug hole in a 8 valve head.

in CA or OR?
or somewhere else still on Vacation.....

[dgyver]

I was not sure if there is enough clearance next to the valve cover for a plug to fit without hitting the valve cover. I have a couple of heads that have some "issues", so they may be the subject for experimentation.

I guess that dual coils would be required as well.

[werase643]

yea a set off of a I-4 will work

[octane]

Hey guys...been absent a while. While ignition is not my area of expertise, I had a thought. If the GS motor is essentially half a Gixxer motor, why couldn't you use the gixxer coils?

[dgyver]

GSXR coils have dual outputs so they only have 2 coils to fire 4 plugs.

[davipu]

yeah i sobered up.  for a while anyway.  back to the topic at hand, then you whould only need one gsxr coil, or if you went with dual plugs you could use both

[94suzuki500]

Well the last that I checked of the gsxr coils they had 4 coils all exactly alike.  They sparked twice so one of the times it sparked it wouldnt ignite because the piston wasnt compressing anything.  I dont know what year but I beleive it was for the 01-03 or somthing like that.

[werase643]

the old skool gsxr coils have 2 wires coming out of one coil
modern gsxr have 4 individual coils  

figure out the ohmage needed...and get a set of DANA coils
for a I-4 if you go with the dual plug idea.

[tkm433]

Anyone know of any larger/higher capacity coils that can be used on the GS?

I have seen some used from another manufacturer, Honda I think, but can not remember which model.

http://nology.com

http://nology.com/profiremotor.html
Being that the GS500 is not a common bike that one might replace the coil on I feel that they do not list an application for the bike but they do offer a coil that would work with the GS500.

http://nology.com/hot.html
They do not list a application for the GS500 but the HotWires should work with a GS500.  Read the info about them since they tend to produce a hotter spark in a shorter time frame than stock wires and this can casue the timing to be off so you might have to retard the ignition in some cases.

[scratch]

Hmm...I'd do the Hotwires, with the stock California ignition timing; in a year maybe; I hafta wait until the bike fund kicks back in.

[Bob Broussard]

I run Dyna coils. 3 ohm single wire units.
I've used Nology coils. They are smaller and lighter than the Dynas, but I had the plug wire connector break inside the coil. Dynas are tougher.
Neither coils mount in the stock mounting holes, so I had to make a mounting bracket.

[dgyver]

Hey Bob...do you have any of the specs on the stock coils?

I found the info on the ones you have, DC3-1
Primary: 3.0 ohms
Secondary: 14,000 ohms

[Bob Broussard]

Primary--3 - 6 ohm
secondary 18 - 30k ohms