I've read the how to in Practical Sportsbikes, only problem is it doesn't really tell you how to Anything to watch for? I was thinking of using Stick Coils from a ZX9R-E2 on my KR1000 No2 (modified version) and GSXR600 or CBR600 Stick Coils - due to their availability and value on Ebay. They all use Denso Coils so connectors are the same. Not sure of compatibility vs Spark Plug size - do they fit the old larger spark plugs if the later bike has smaller threaded plugs?
Thanks Chris, useful. Looks like I can use ZX9R Stick Coils for fitment at least - just need to understand the resistance. The mags article just says wire them in, no info on which ones, plug differences / fixed mounting necessity or resistance, another 'how to' article that doesn't tell you 'how to'
Denzil on here (but not for a while) could probably shed more light. I do know that something important was not discussed on the Aprilia site and that is the danger of overloading the original amplifiers (or drivers in other systems) by lowering the resistance of the coils. It's possible that the spark may be improved but it could be at the expense of the rest of the system. I'm sure i'm one of many who had your thoughts cross their minds but I would want to fit the compatible amplifiers/rest of ignition system to be truly happy or at least follow some sound electrical theory if I were to risk todging together two systems. I don't know if you went on to read the additional link near the end? - he fitted 0.9 ohm coils in place of 1.3 ohm standard units and had covered 8K miles so was useful to read.
Agreed, I've never had any problems with 'old-fashioned' coils on any vehicle but at the last service my car had all it's coils changed (precautionary - warranty/recall so I'm told?) and just this week my Son's had 2 stick coils fail on his car...
Did think about changing mine but MrR and DD might have a point.Besides theres nothing wrong with the originals.If it aint broke and all that.
Maybe but I don't have any, a set of Dyna coils with leads will cost me about £150.00 but good low mile second hand stick coils off a jap or triumph with sub harness will cost about £60 and the modified version of the KR I'm building will look cleaner without the coils. The other more standard version will use traditional coil packs. The article in Practical Sportsbikes which shows how to do it says better performance and reliability - but saying that, it doesn't really tell you how and doesn't mention resistance, which way to wire etc - in fact a pretty useless article. I will have to have a think on this one, thanks for the comments
It's pretty easy stuff really. Simple questions first: how many regular coil packs does your bike run as standard? what's their resistance? whats the resistance of your intended COP coils? Either way for what you're after, you'll still wire it as a wasted spark system anyhoo. @figaro - its a reliability thing, you take another variable (the cable) out of the equation and thus can control the spark better as the path to the plug is shorter. Also, for packaging reasons you can stuff them in tighter places, and also the coil windings can be smaller and more efficient as you're only needing to worry about the single plug rather than two/three/ four plugs on a grouped coil pack for instance.
It's an in line 4 GPz1100 Engine - two coil packs, it had 2 x 3.0 Ohm Dyna Coil Packs fitted which are now on my Z1 so I was guessing 1.3 or 1.5 Ohm Sticks?
okey dokey well first of all the you're correct in using roughly half the resistance of the stock coil for each one as you're replacing it with two coils. next up is the wiring. If you can get hold of the wiring diagram or the harness of the COP unit then discern which is the power supply - it may be that two coils receive power and then daisy chain the signal from the system. so for example say- coil pack 1 fires 1+4 Coil pack 2 fires 2+3 it'll be a wasted spark ignition so both plugs fire. so for argument sake in our example coil pack 1: Cylinder 1 cop has say a black- and a red wire+. Lay out the plugs for the coils that will go between cylinders 1 and 4 and cut one of the black wires to length so that it will join up with one of the non-black wires on the other connector. In other words, you are joining the negative side of one coil to the positive side of the other coil. on cylinder 1 you will keep the red +VE, and on cylinder 4 you would connect the lead which would provide the signal from your ignition system. Connecting the coils in this manner makes it so that the ground is switched on the coils. If you can get the links for a wiring diagram for the coils you want to use, and a link to the wiring diagram for the bike then I can scribble a small schematic.