What resistors are you guys using to convert to COPs. My stock coils primary is 3.0 ohms. My Denso sticks are 1.3. So what is everyone using? 2.0 ohm, 50 watts? I have a feeling people are using smaller resistors since it's not constant current.
What resistor for COP conversion
- Thread starter AMechEng
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- conversion cop resistor
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alorio1
Well-Known Member
Here is some info that might intrest you...........
http://www.vmaxforum.net/showthread.php?t=5427
http://www.vmaxforum.net/showthread.php?t=5427
wildweasel_pt
Well-Known Member
1ohm 20W is enough. I have an extra set that I can let you have for the price it costed me. Enamel resistors for heat resistance and good dissipation. I can email you the specs if you wish
Bill Seward
Well-Known Member
I never added resistors to my COP setup on my '85. So far not a problem, but your mileage may vary.
Thanks guys. I've got the stock coils out now so that I could use the space for my fuel pump. according to USPS tracking I won't have the resistors I ordered until Saturday and I'm taking the bike to the Keys Friday so I'm going to button it up without the resistors and see how it fairs.
wildweasel_pt
Well-Known Member
Be careful as early analog TCIs are prone to burn as current rises due drop in cops primary resistance.
I'm not sold that the CDI's need resistors. We do sell the resistor adapters for peace of mind but I just don't think it needs it. Besides, if it burns up then that's a good excuse to get the Ignitech CDI box which doesn't need them!
Sean
Sean
I laughed when I saw your mileage. I'm around 18000 miles on mine.
davesax36
Well-Known Member
Well that's one of the other side-effects of no resistors.... :ummm:
(I run the resistor ones on mine because I bought my kit from Gannon)
88vmx12
Well-Known Member
I think the main issue was what coils were being used, that is when failure occurred.
G
dingy
Well-Known Member
With a TCI the coils are continuously powered, except for brief interruption of current in negative side of coil circuit, which causes the coil field to collapse thus firing plug.
A CDI works the opposite, coil is triggered by a brief flow of current through the coil, majority of time coil circuit has no current flow.
With mostly constant current flowing through coil circuit, the power the resistors need to dissipate is higher than what would be needed with a CDI controller.
The Ignitech TCI has a dwell setting that compensates for the lower coil resistance. They recommend the dwell be shortened with coils that have a primary resistance less than 2 ohms.
Gary
