Member Contributer kaldek Posted March 2, 2012 Member Contributer Share Posted March 2, 2012 Exactly. The coils are NOT the same resistance. And I don't wanna toast my ECU. If I already had a spare ECU I'd go for it. I can't remember now if I'd clarified this (as it was last year), but it's possible that just banging on a resistor in series with the +12v feed to each coil to bump it up to 3.2 ohms could work fine. I found some articles where people are already doing this on cars when the coil primary winding resistance was too low. So if the coils are 1.6 ohm but need to be 3.2 ohm, a 1.6 ohm resistor in series with the coil could be the way to go? Ultimately we need RangerScoot to get around to backprobing his coils and measuring the current with a digital oscilloscope and ammeter. If it tops out around 7 amps on his new coils - all is good. I have all the tools needed right here....in Australia. Quote Link to comment Share on other sites More sharing options...
Veefer800Canuck Posted March 2, 2012 Share Posted March 2, 2012 I already thought about the resistors. Dunno if it would work or not? I suspect it would. Quote Link to comment Share on other sites More sharing options...
Member Contributer kaldek Posted March 2, 2012 Member Contributer Share Posted March 2, 2012 I already thought about the resistors. Dunno if it would work or not? I suspect it would. It should, considering that the purpose of the resistor here is merely to ensure that the coil does not get overcharged and that the coil does not demand so much current that the transistors in the ECU burn out. What I'm unsure of is whether the flyback voltage (10 microsend 400 volt pulse) could damage the resistor. It would be extremely low current though, so likely not. I suppose the right resistor would be a combination of ohms and the right wattage. And that's where my knowledge gets very hazy. Right now there are electrical engineers sharing this URL and laughing their asses off, I'm sure. Quote Link to comment Share on other sites More sharing options...
Member Contributer jeremy77 Posted March 2, 2012 Member Contributer Share Posted March 2, 2012 So I'm not sure about just adding a resistor to the chain to increase the coil resistance. It seems to me that the coil itself needs to provide the resistance. But I'm no electrical wiz... That being said I have spent the last half hour trying to hunt down a COP with 3+ ohms on the interwebs and have come up dry all the way around. Has anyone else found any COPs with more than 1.6 ohms? Quote Link to comment Share on other sites More sharing options...
Member Contributer jeremy77 Posted March 2, 2012 Member Contributer Share Posted March 2, 2012 Another piece to consider is that a used ECM is available on eBay for $40-60. So add to that a set of CBR coil on plugs and you're looking at about $100 to try this plus time. So its not tons of money but a hundred bucks is a hundred bucks. Quote Link to comment Share on other sites More sharing options...
Member Contributer kaldek Posted March 2, 2012 Member Contributer Share Posted March 2, 2012 So I'm not sure about just adding a resistor to the chain to increase the coil resistance. It seems to me that the coil itself needs to provide the resistance. But I'm no electrical wiz... Resistance in series can absolutely work. There's lots of info and circuit diagrams showing how to do this, and it's the reason why running two 1.6 ohm coils in series results in 3.2 ohms of resistance. Same thing. Quote Link to comment Share on other sites More sharing options...
Member Contributer jeremy77 Posted March 2, 2012 Member Contributer Share Posted March 2, 2012 Sorry... I was picturing the tiny little resistors you get at Radio Shack. So a resistor such as, wired between the + side of each coil and the ECM... Probably mounted to the frame to serve as a heat sink? Quote Link to comment Share on other sites More sharing options...
Veefer800Canuck Posted March 2, 2012 Share Posted March 2, 2012 Ooh that is enormous. So much for streamlining the wiring and jettisoning excess bulk/weight! Quote Link to comment Share on other sites More sharing options...
SEBSPEED Posted March 2, 2012 Share Posted March 2, 2012 Sorry, but I have to turn this whole thread on its ear. I talked to Poncho about this, he's a master electrician so I figured he'd be the best person to ask. Resistance has very little to do with this. That is, the primary resistance we're all checking with our meters on the coil terminals. The secondary resistance, which is checked by measuring resistance from coil to plug end of wire, also has little to do with this. The one thing that truly determines if there is any benefit or risk to this mod, is the IMPEDANCE VALUE of the coil. A coil with a lower impedance than the oem coil, will flow more current. More current flow (or should I say, less restricted current flow), will increase current flow through the upstream components (read: spark box/CDI/ECU), and within that condition lies the potential for damage to those components. Discuss. Quote Link to comment Share on other sites More sharing options...
Veefer800Canuck Posted March 2, 2012 Share Posted March 2, 2012 How does one measure the impedance value then? Quote Link to comment Share on other sites More sharing options...
Member Contributer jeremy77 Posted March 2, 2012 Member Contributer Share Posted March 2, 2012 First of all, no fair consulting someone who actually know what they're talking about! The one thing that truly determines if there is any benefit or risk to this mod, is the IMPEDANCE VALUE of the coil. so it seems, according to this, the we are in need of a 3.2 ohm COP if this is gonna work... Back to the googlery Or are we now talking about something in the range of 10,000-20,000 ohms? I've seen coils listed as either 3 ohms or 15,000 ohms Quote Link to comment Share on other sites More sharing options...
The Phantom Posted March 2, 2012 Share Posted March 2, 2012 Perhaps Fireblades.org has someone who's taken COP sticks from a later CBR and fitted them to an earlier model... not that I am advocating stealing IP from another forum But if someone has done this mod to a Honda, that's the logical place where it would be documented... Quote Link to comment Share on other sites More sharing options...
The Phantom Posted March 2, 2012 Share Posted March 2, 2012 Few more data points. Not on Fireblades.org, but someone did it fairly simply on a Blade... no mention of how long it lasted though. http://www.rrzone.co...72191#post72191 I found someone who switched to COP on a FZR600 and went on to rack up 15,000 miles on the bike with no problems: http://www.fzronline.com/forum/viewtopic.php?f=8&t=3187 And his how-to: http://www.fzronline.com/forum/viewtopic.php?f=43&t=6316 Quote Link to comment Share on other sites More sharing options...
Member Contributer kaldek Posted March 2, 2012 Member Contributer Share Posted March 2, 2012 Sorry, but I have to turn this whole thread on its ear. I talked to Poncho about this, he's a master electrician so I figured he'd be the best person to ask. Resistance has very little to do with this. That is, the primary resistance we're all checking with our meters on the coil terminals. The secondary resistance, which is checked by measuring resistance from coil to plug end of wire, also has little to do with this. The one thing that truly determines if there is any benefit or risk to this mod, is the IMPEDANCE VALUE of the coil. A coil with a lower impedance than the oem coil, will flow more current. More current flow (or should I say, less restricted current flow), will increase current flow through the upstream components (read: spark box/CDI/ECU), and within that condition lies the potential for damage to those components. OK so you're saying that using resistors won't stop the coil from pulling too much current. I get it! Quote Link to comment Share on other sites More sharing options...
douglasthecook Posted March 2, 2012 Share Posted March 2, 2012 You guys made my brain hurt, which is pretty impressive considering that the brain supposedly has no pain sensors!!! Quote Link to comment Share on other sites More sharing options...
SEBSPEED Posted March 2, 2012 Share Posted March 2, 2012 How does one measure the impedance value then? You'd need to test and compare current flow of both coil types somehow. Quote Link to comment Share on other sites More sharing options...
Member Contributer kaldek Posted March 3, 2012 Member Contributer Share Posted March 3, 2012 How does one measure the impedance value then? You'd need to test and compare current flow of both coil types somehow. Isn't this the one case where you can just measure the resistance across the terminals of the coil, and the result is indeed the impedance? I know all our talk about resistors in series wasn't right now, but isn't this measurement an exception? Quote Link to comment Share on other sites More sharing options...
SEBSPEED Posted March 3, 2012 Share Posted March 3, 2012 How does one measure the impedance value then? You'd need to test and compare current flow of both coil types somehow. Isn't this the one case where you can just measure the resistance across the terminals of the coil, and the result is indeed the impedance? I know all our talk about resistors in series wasn't right now, but isn't this measurement an exception? No, there is more to it. Something about electromagnetic something or other. I wish Bernie would get back online to help out with this. Quote Link to comment Share on other sites More sharing options...
Member Contributer kaldek Posted March 3, 2012 Member Contributer Share Posted March 3, 2012 How does one measure the impedance value then? You'd need to test and compare current flow of both coil types somehow. Isn't this the one case where you can just measure the resistance across the terminals of the coil, and the result is indeed the impedance? I know all our talk about resistors in series wasn't right now, but isn't this measurement an exception? No, there is more to it. Something about electromagnetic something or other. I wish Bernie would get back online to help out with this. That might mean that the CBR stick coils - even though the measured resistance is wrong - could be just fine for our purposes... Quote Link to comment Share on other sites More sharing options...
V4 Rosso Posted March 3, 2012 Share Posted March 3, 2012 Isn't this the one case where you can just measure the resistance across the terminals of the coil, and the result is indeed the impedance? I know all our talk about resistors in series wasn't right now, but isn't this measurement an exception? No, impedance of a coil varies with the frequency of the AC signal. A regular Ohmmeter measures resistance using DC. Resistance only slightly changes with temparature. Also a coil designed for CDI has a different step up compared to a coil designed for TCI so you can't mix them or you'll likely end up with a very poor spark. Quote Link to comment Share on other sites More sharing options...
Member Contributer kaldek Posted March 3, 2012 Member Contributer Share Posted March 3, 2012 No, impedance of a coil varies with the frequency of the AC signal. OK, now I'm *really* confused. Quote Link to comment Share on other sites More sharing options...
Member Contributer Mohawk Posted March 23, 2012 Member Contributer Share Posted March 23, 2012 I've added CBR1000RR CoPs to my 5th Gen, 2-wire units, 2007 model I think, needs an O-ring to seal the plug tunnel & keep the the CoP from flapping about, but I ran the rear 2 for 3 months on CoP & the front on standard coils as a test, works fine. Will be adding the front 2 CoPs during my rebuild at the moment. Quote Link to comment Share on other sites More sharing options...
douglasthecook Posted March 23, 2012 Share Posted March 23, 2012 I've added CBR1000RR CoPs to my 5th Gen, 2-wire units, 2007 model I think, needs an O-ring to seal the plug tunnel & keep the the CoP from flapping about, but I ran the rear 2 for 3 months on CoP & the front on standard coils as a test, works fine. Will be adding the front 2 CoPs during my rebuild at the moment. How did you wire these up, do you have a pic or a diagram for us electrically uninclined? Thanks! Quote Link to comment Share on other sites More sharing options...
Member Contributer Mohawk Posted March 23, 2012 Member Contributer Share Posted March 23, 2012 Oh and another thing re the CoP issue. I tested the ones I've used & if memory serves the resistance was about 3ohm of the orginals & only 1.5 on the CoP, so I ran the rear two, then had a brain wave, that resistance increases with Temperature, so got everything ready to test the rear CoP with the bike hot, remember that CoP sits in the plug tunnel surrounded by HOT metal. It took about 2-3 minutes to stop bike get off, get meter & attach whilst trying not to burn myself & the resistance hot was 2.5 so close enough in my opinion & has been running great since ! 1 Quote Link to comment Share on other sites More sharing options...
SEBSPEED Posted March 23, 2012 Share Posted March 23, 2012 Oh and another thing re the CoP issue. I tested the ones I've used & if memory serves the resistance was about 3ohm of the orginals & only 1.5 on the CoP, so I ran the rear two, then had a brain wave, that resistance increases with Temperature, so got everything ready to test the rear CoP with the bike hot, remember that CoP sits in the plug tunnel surrounded by HOT metal. It took about 2-3 minutes to stop bike get off, get meter & attach whilst trying not to burn myself & the resistance hot was 2.5 so close enough in my opinion & has been running great since ! How many miles have you put on this setup? Quote Link to comment Share on other sites More sharing options...
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