Please help a dummy understand this whole resistance thing

As we know, a number of parts manufacturers recommend 5K resistor caps for various applications (Sparx, Trispark et all). Now here is where my confusion lies; are these recommendations based on a target value for resistance between the coil and the plugs? If so, does it take coil resistance into account?

Example: My Dyna coil has a resistance of 5K, wires are unresisted, caps unresisted, NGKR resistors. Should the resistance of the coil not account for the recommendations made by both Sparx and Trispark for their products? I'm wondering at this point if, by stacking one resisted component onto another in this circuit I'm needlessly weakening my spark.

Re: Please help a dummy understand this whole resistance thi

No.

The coils internal resistance is on the PRIMARY (input) side, this is what the ignito unit "sees".

The output of the coil must also "see" a certain resistance; this can be in the caps, wires or plugs, but has to be within a certain range.

Re: Please help a dummy understand this whole resistance thi

The coil resistance has to do with how power flows from the switch and though the IGN black box.
The resistor caps are to control High Voltage spill over into the voltage regulator.
The digital IGN boxes can also suffer from high voltage leaks . Follow directions from the maker of the equipment used.
As long as your new system is stronger than your old one over all, your good.

Re: Please help a dummy understand this whole resistance thi

Ok, so any harm in going from a 5ohm coil to a 3ohm coil?

Re: Please help a dummy understand this whole resistance thi

A Boyer will not like a 3 ohm coil, the current draw will be too high and the box will overheat with too many electrons :mrgreen: .

Re: Please help a dummy understand this whole resistance thi

acadian said:

Ok, so any harm in going from a 5ohm coil to a 3ohm coil?

Click to expand...

http://www.boyerbransden.com/pdf/KIT000 ... 00017_.pdf

A single dual output coil can be used as long as its primary resistance is more than 3 ohms.This should be mounted
on the frame in a manner that will take the heat from the centre core.

Click to expand...

Re: Please help a dummy understand this whole resistance thi

I was always under the impression that resistor caps or resistor plugs were to control RF interference with radios and electronic devices such as some regulator/rectifiers?

Re: Please help a dummy understand this whole resistance thi

I have tried to use the 1 ohm Harley coils for customers that have scored them swap meets; they just pull too much juice.
A fully charged battery has all the power it needs to fry your black box just put a low (one ohm) coil on and find out very quickly it will run for just a while. If you put a AMP meter in line on the battery you would see it pulling down 4-5 Amps instead of 2-3 Amps. The funny part is all that power has no place to go, no work to do. As soon as the system has overcome the resistance of compression and sparks the cycle starts all over again. You can have a 40,000 volt IGN system and if your motor only needs 10,000 to run then it's all a waste sort of. Now you need more power than the stock system up at the high revs when the motor makes real power and a strong system will help with our gas now that it less Volatile.

Ron, Red box Boyers need the caps they are Digital. Black box are a chip (hard wired memory) Many have tried the red box and never got it to work as it should. Resistor caps and careful wire routing seem to come to play on these. They also don't like AC wires near the trigger leads. High voltage leaks mix up the brains as well.

Upgrading the IGN system is something you can feel in the seat of your pants, as long as it's better than stock it matters very little how you get it working all the time over time. You can feel this best at the very top end (top speed) should improve with upgrades, learning how much extra plug gap can be handled by you new system is a whole other thing to talk on.

Re: Please help a dummy understand this whole resistance thi

I just don't get how some people can make it so blindingly hard, when it's actually so simple.

I use plain ol' lead-acid batteries (most of the time), Sparx ignition units with dual 6v Bosch coils (most of the time, I've used 12V Blue Streak dual lead units), and plain copper wires with plain plugs. Also use Sparx solid state rectifier/regulator box.

ZERO ISSUES.

My race bike, a box-stock Triumph 650 had it's battery installed in September of 2007 and is still humming along without ever having a trickle charger on it. Runs clean right up to 7,000 RPM and I'm positive it'll spin up higher without a misfire.

All of the Nortons I've built over the last 6 years have the same experience, EXCEPT one that didn't like a small AGM battery and ate it up.

"stick with what works"

Re: Please help a dummy understand this whole resistance thi

I believe Ron is correct. The resistance (5k in plugs, cap, or wires) is there to limit the peak current when the plug fires to 5 amps or so. Without it, the peak current spikes would be quite high, and radiate as a magnetic field pulse throughout the nearby space, which would include the harness and all electronic modules. In addition, this current pulse is transformed accross the coil into the primary circuitry. While this effect is not destructive, it does interfere with modules that depend on counting pulses to operate, or are easily reset by spurious pulses. Most manufactures of EI and regulator/rectifier modules warn of this effect and require resistance somewhere in the HV circuit. Since all interesting new plug technologies (iridium, platinum, e.g.) appear to be offered in only resistive form (4-5 kOhms), using them requires non-resistive caps and wires.

Re: Please help a dummy understand this whole resistance thi

The coil resistance is to limit current inside the electronic ignitions.
Each model ignition has its own tolerance-preference for total coil ohm.
Black box Boyer analog like ~4.2 ohm total. Higher grade systems can handle less ohms more current surges.

The resistance in the HI voltage side is to limit-suppress RF interference-static.
The extra resist in Hi tension leads Or plug caps mainly just lets voltage build higher till jumps a spark. There is a slight spark time retarding effect by upping resistance
and takes a tad longer for flux collapse to pump up enough to spark. No need to run both R caps and R plugs and R leads, just one in a row will do it. More might back fire into the ignition brains.