Zx coil over plugs

[alex.s]

They work great

[Alex]

Snazzy.

[KELPHYN]

Notice any difference performance wise?

[alex.s]

Originally Posted by KELPHYN

Notice any difference performance wise?

none what-so-ever; as it should be. the difference is merely in how much space the coils take up... this way, they dont take up any extra space. it's kinda more of a farkle for engineers i guess... not really any benefit outside of saving a few ounces and the space (and how it looks)

although i did blow up my engine at the track a few weeks after putting them in, so maybe it was related :P :P

[choneofakind]

I think they look sick. I like your valve cover too. I want to paint mine black next time it's off in the spring. Plain old high temp paint? Any surface prep?

[KELPHYN]

Just thought they might help with top-end if they had a higher output.

[cuong-nutz]

What year ZX10r plugs did you use? Are the ZX6r plugs the same? Does different redlines of the two bikes affect characteristic of the plugs?

[alex.s]

its from an 05 06 zx636. it is from a CDI ecu which is a requirement for that type of coil (the 250 is also CDI, not TCI or others which will NOT work with a cdi ignition system)

the gains from this type of coil comes from the lowered resistance going from the collapsing field into the output coil and into the plug... if you look up joules law you'll see as you lower that resistance, you get higher inductance joules going through the plug for the same amount of charge current (from cdi) which means the spark is hotter and will last slightly longer. just make sure the coils are suited for the type of plugs you use otherwise you could melt a plug. (the 05 kawi 636 uses the same plugs as the 250)

[choneofakind]

Alex, post 8 was great. Thanks for the explanation.

Hotter spark that lasts longer means longer burn or more consistent burn or...? Sorry, I'm still figuring out that part.

[alex.s]

well so if you have a weak spark, you are only igniting a part of the fuel, and then that fuel ignites the rest. if you put more joules through the plug (joules is basically heat... factor of power over time) then the spark contributes to igniting more of the fuel. if you are running very high RPM with high compression (lots of other circumstances but these effect it the most) then its possible to complete the burn cycle while still having unburnt fuel. having a hotter spark can start the combustion faster, which means you are able to get a more complete burn. more fuel burnt, more power output.

[choneofakind]

Again, thanks. That helped.

Is the difference noticeable at the top end or is it fairly minimal? I assume these aren't too pricey.

[alex.s]

Originally Posted by choneofakind

Again, thanks. That helped.

Is the difference noticeable at the top end or is it fairly minimal? I assume these aren't too pricey.

for a stock setup, the difference shouldn't be obvious as the stock coils are "good enough". but when you get into higher performance stuff like changing timing and compression, you can get larger changes. racerx has takai coils (better than zx coils) and is running much higher compression and agressive cam and ignition timing and will be doing a dyno with them at the end of the month so follow his thread for the results.

[cuong-nutz]

Was searching up aftermarket ignition coils: http://motor.otomotifnet.com/read/20...i-Ninja-250-F1

[micoulisninja]

Originally Posted by alex.s

its from an 05 06 zx636. it is from a CDI ecu which is a requirement for that type of coil (the 250 is also CDI, not TCI or others which will NOT work with a cdi ignition system)

the gains from this type of coil comes from the lowered resistance going from the collapsing field into the output coil and into the plug... if you look up joules law you'll see as you lower that resistance, you get higher inductance joules going through the plug for the same amount of charge current (from cdi) which means the spark is hotter and will last slightly longer. just make sure the coils are suited for the type of plugs you use otherwise you could melt a plug. (the 05 kawi 636 uses the same plugs as the 250)

Alex do you believe it would make a difference on the FI models too ??

[alex.s]

i think it makes very little difference in either unless you are running very aggressive timing. also, my understanding of the way the system works when i wrote that was slightly naive. i believe the most important aspect is how quickly the field is able to collapse into meaningful heat, and stay in a range that the plug is designed for. and how reliable the size of the field is so you don't over-charge the field and burn electrodes. (ie- what other influences are having an effect on the field near the coils, as well as the charge going into the coils before they collapse... so cdi is another big part of it as well as proper voltage regulation)

[sharky nrk]

I like it, one less thing in the way lol.

[cuong-nutz]

Found this info on the line and decided to dump this here for reference.

Just a quick FYI,
Thanks to original poster on ZXROA.

The coils that work for the mod must be 5 in. long and have aprox.
resistance of 1.3-1.5 ohms ea., here's some info I got, will update.
These are the p/n's and years that work, any other may not work.

Suzuki GSXR: 1000 (01-07), 750 (01-05), 600 (01-03)
oem p/n 33410-35F10/35F00 (Denso p/n 129700-4400/4150)
4400/1.5 ohms, 4150/1.3 ohms
new aprox. $69

Kawasaki: ZX10/14 (04-07) oem p/n 21171-0005/1.5 ohms
ZX9 (99-03) + ZX12 (03-05) oem p/n 21171-1265/1286
Z1000 (03-07) + Z750 (05-06) 21171-1286
Z1000 denso p/n 129700-4580/1.5 ohms
ZX6 oem p/n 21171-1282/mitsubishi#F6T560
ZX9 denso p/n 129700-3630/1.3 ohms
ZX10 mitsu.#F6T549/560
ZG14/08(Concours) # F6T560

[Ghostt]

interesting I may have to put this on my list of things to do. I like the idea of eliminating the plug wire, as one less thing to go wrong

So from what I'm understanding it's a Plug-N-Play install?

[alex.s]

Originally Posted by Ghostt

interesting I may have to put this on my list of things to do. I like the idea of eliminating the plug wire, as one less thing to go wrong

So from what I'm understanding it's a Plug-N-Play install?

the connectors for the stock ninja 250 coils are those old school crimp on connectors. the zx style plugs use a little two wire connector thing... so its hard to connect the coilovers without the right connectors.

[Ghostt]

Originally Posted by alex.s

the connectors for the stock ninja 250 coils are those old school crimp on connectors. the zx style plugs use a little two wire connector thing... so its hard to connect the coilovers without the right connectors.

Okay thanks, seen some on eBay, that also includes the wiring harness,

[garth285]

I am using the ninja 300 coils on my turbo 250, they fit very nice as well.

[crazymadbastard]

Originally Posted by garth285

I am using the ninja 300 coils on my turbo 250, they fit very nice as well.

Are those compatible with the pregen/negen ignition? also what type electrical plugs do they use?

[garth285]

Originally Posted by crazymadbastard

Are those compatible with the pregen/negen ignition? also what type electrical plugs do they use?

Not 100% they are basically the same as the zx6 coils though so I'd imagine so.

[crazymadbastard]

Originally Posted by garth285

Not 100% they are basically the same as the zx6 coils though so I'd imagine so.

<3

[Ghostt]

I've done this modification, and a write-up on the subject,

https://www.ninjette.org/forums/blog.php?b=8379