COP's, Resistors & VBoost opening RPM

[Bill Seward]

Devil's advocate here.. I have a set of homemade COPS adapters without resistors on my '85. They've been in service at least 7 or 8,000 miles without a bit of problem. A question to those who know more about this ignition box failure... How long to the setups take to fry the boxes? Immediately, or after a short time? Or are they dying after many miles, say like on the way to Thunder? ('cause I do NOT want that to happen..)

I'll admit that reading all this has planted a seed of doubt about the reliability of my ignitor...

Wouldn't be too hard to add resistors somewhere in the harnesses, as I made them all a bit longer than absolutely necessary. Any advice on what resistors to add? Are they a Radio shack item??

 

[wildweasel_pt]

Bill
It all depends on what COPS you use as they have different primary resistances, the closer they are to the stock coils the better but usually they are in the range of 1 to 1.5Ohms and the stock coils are the double so usually a 1ohm power resistor is enought o maintain current on acceptable numbers. I have bought 20w enamel wirewound 1 Ohm resistors and they have been fine and they are rated for ambient temperature on constant load what you know is not the case as they work intermittently as per ignition request so they will be working below normal workload. I have an extra set if you want to play around with them and get them to work and probably save you from frying your TCI.

 

[dannymax]

Devil's advocate here.. I have a set of homemade COPS adapters without resistors on my '85. They've been in service at least 7 or 8,000 miles without a bit of problem. A question to those who know more about this ignition box failure... How long to the setups take to fry the boxes? Immediately, or after a short time? Or are they dying after many miles, say like on the way to Thunder? ('cause I do NOT want that to happen..)

I'll admit that reading all this has planted a seed of doubt about the reliability of my ignitor...

Wouldn't be too hard to add resistors somewhere in the harnesses, as I made them all a bit longer than absolutely necessary. Any advice on what resistors to add? Are they a Radio shack item??

Bill, what's your VBoost opening rpm?

 

[dannymax]

Not sure about the range, but I don't feel the vboost of my 89 at 6k the same way than before. I just never thought it was related to the COPs but something else. I have been look for the reason for quite sometimes. :bang head:

We're trying to figure out if running COP's without resistors results in a delayed boost opening....the guy who discovered this, Rattlehead on the V4musclebike forum, had a normal boost opening of 6k, installed resistor-less COP's and his boost wouldn't open until 7500 after that....so he soldered in some resistors (not sure of the specs) and his boost opening returned to 6k.

My '96 had a boost opening of 7500 and I was running resistor-less COP's but didn't do any 'before' testing, nor did I install resistors, so there is no usefull info there.

 

[Mr. Max]

How about t-boost, does it work with ignitech? With dynatek it didn't work properly.

 

[DMAN999]

Rattlehead used some 1.5 ohm 25 watt resistors (shown below) on his.
He has the Denso 129700-3630 - 1.3 ohm COPs

 

[Diablotin]

We're trying to figure out if running COP's without resistors results in a delayed boost opening....the guy who discovered this, Rattlehead on the V4musclebike forum, had a normal boost opening of 6k, installed resistor-less COP's and his boost wouldn't open until 7500 after that....so he soldered in some resistors (not sure of the specs) and his boost opening returned to 6k.

My '96 had a boost opening of 7500 and I was running resistor-less COP's but didn't do any 'before' testing, nor did I install resistors, so there is no usefull info there.

I have the resistors so it's most likely something else. I don't need to be at 7500k to feel it. It's just I don't feel it much since I got the COPS maybe coincidence only.


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[dannymax]

Rattlehead used some 1.5 ohm 25 watt resistors (shown below) on his.
He has the Denso 129700-3630 - 1.3 ohm COPs

Thanks Dennis....I don't talk that language so good.....:blink000:

 

[DMAN999]

I have the Denso 4400 1.5 Ohm Cops and the wires with resistors:
http://www.vmaxforum.net/showpost.php?p=263890&postcount=1

My VBoost starts opening at just under 6k rpm, just like always, after installing them.
A properly working Vboost system is supposed to start opening at 5750 rpm and be fully open by 8k rpm.

 

[maxed141]

Resistor would go on the positive lead, of the new harness correct??

 

[fogman62]

I hear the warnings of running cops without resistors but I haven't read of many that have failed.I do not remember reading of any .I may have missed it a post .What kind of failure rate do we have. I would like to run them but i am just being cautious.

Thanks,
Gary

 

[wildweasel_pt]

Resistor would go on the positive lead, of the new harness correct??

Im no electric engineer but relying on my background and knowledge about electrons i'd say it doesn't matter, but Gary (dingy) its much better on this matter and should confirm if what i say is true in all aspects.

I hear the warnings of running cops without resistors but I haven't read of many that have failed.I do not remember reading of any .I may have missed it a post .What kind of failure rate do we have. I would like to run them but i am just being cautious.

Thanks,
Gary

The early models (85-89) are analog type TCIs so use less recent technology comparing to later type digital TCIs (same thing as RRs). The inner components are not as resilient or current capable as the newer models, so due the increase in current in the circuit caused by lower primary resistance on COPS, the transistors are prone to burn because they cannot cope with the increase in current described earlier, the higher the resistance in COPS, the lower the increase in current is, though COPS usually have around 50% or more lower resistance than regular coils, thats why that adding a power resistor brings the resistance back to stock values, looking at the circuit resistance wise (thats what current depends on as voltage is constant) having a COP with 1,5 Ohm in series with a resistor with 1 Ohm is the same as having a coil with 2.5 Ohm. It has to be a power resistor to cope with the current and not burn like would happen if one were to use one of those smaller ones like on the circuit boards.

 

[Diablotin]

I guess that's the reason why Gannon did put a resistor on first hand. This way the kit remains compatible with both generation of cdi.

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[Redbone]

I ran non resistor cops for 2 years with my '92 ignition but switched to Gannon's resistored cops when I went with a Dyna 3000 ignition. No issues whatsoever with either setup and the vboost operates as normal.
It is interesting the work that Traumahawk is doing with the Inigtech ignition so that may be a way to go for me in the future.

 

[Traumahawk]

It is interesting the work that Traumahawk is doing with the Inigtech ignition so that may be a way to go for me in the future.

At Eureka Springs, I'm gonna let several people test ride the bike, so they can see how the unit reacts.

 

[fogman62]

Must not be much of a failure rate,I heard of a lot of success running without them but I understand why you should,
Thanks,
Gary