Stick Coils....

[alext]

Ok so I want to fit stick coils to the VFR750FJ/K engine I have in my VF750!!

the wiring from the cdi to the original 4 coils is as follows..

Blu/Black to coil-1

yellow/white to coil-2

red/bue to coil-3

red/yellow to coil-4 this then goes off to the rev-counter

the other connector off the original coils joins ALL together into a black/white and this goes to the engine stop switch!

 

the coils Im using are GSXR600 ones (generic denso 129700 series) with 2 wires on the top - bought the wiring plugs new separately, so the wiring on the plugs is no help! looking at what I can see on the web, the blue is meant to be + and the orange is - !

what I want to clarify is the following:-

(1) does it matter what connector on the stick coil is which? Im not having to cope with going from twin OEM coils to 4 separate cos the VFR has 4 coils of equivalent resistance. All the diags I find on the web are for this 2 to 4 coil conversion.

(2) is the black/white through the stop-switch a power or a ground? - my mind says its a ground, but surely that wouldnt work - the coil needs 12v and a signal, so it must be power, the other wires from the cdi are the signal - ground is through the plug.

any leccy-experts out there who can help??

ta Alex

 

[EXUPDEL]

I looked at doing this but found the front coils hit the back of the fan on the radiator on a 96 vfr750 so didn't bother trying to take it further.

Can someone explain how to check and compare impedances?

I understand coils from an inline 4 work as pairs in series. However on a V4 there is a single coil for each cylinder. 

How do the 2 compare?

[EXUPDEL]

Ok workshop manual says primary 2 to 4 ohms. Secondary 17 to 24 kohm.

The v4 has a coil for each spark plug because of the firing sequence. No 2 pistons are at t.d.c. at the same time.

[alext]

so, further checking implies... the + side of the stick goes to the black/white  through the  stop-switch, and the - connects to the coloured wires from the CDI.

for the resistance - Ok Im beginning to understand... the lower impedance will make the cdi work more / give a smaller spark.

 

Edited November 28, 2020 by alext

[EXUPDEL]

Thanks @sev

What happens if you use sticks with a lower resistance? Or vice versa?

 

 

 

[RonniB]

Lower resistance coils will draw more amps in your cdi, which can kill it. It also affects the stick coils since the soak time will be too long since the fairly basic cdi doesn’t control, which can kill the coils.

so your best options are:

- use the 1.6ohm stick coils you have with a programmable cdi, like ignitech or similar.

- or get stick coils with the same resistance as the oem coils, the ones Sev mentioned, and stick with your std cdi.

I would go with option 2, since ignitechs are known to drift in their settings. I did something similar long ago on a NC30 and it worked very well

[EXUPDEL]

Thanks chaps I have learnt shit loads tonight. 

Hopefully helping the original poster.  Interesting info regarding sticks vs coils. 

What sort of tolerance would you suggest  be used on the resistance. I have just done a stick conversion on a cbr6. The original coils have a 3.2 ohm resistance the sticks are 1.7 in series so that's 3.4 as a pair. 0.2 ohms higher. Is this an issue?

[fastfreddybikes]

I wish I was brighter. Fuck knows how I’ve got through life knowing and understanding what little I do. 

[EXUPDEL]

@sev

I have made a loom as per diagram 1. On the bike side there are 2 spurs 1 for each of the original coils. So i have just replicated the plugs as per original. I am still using the oem honda cdi. Havent got as far as investigating ignitech cdi's. I am just happy my bike runs

 

@alext when you put the sticks in the front cylinders of the vfr did you find the fan shroud hit the tops of them? 

[EXUPDEL]

12 minutes ago, sev said:

ok, so if you've run then as per option 1 you might find that you'll suffer from a weak spark and its associated symptoms - just be mindful of that.

Ok thanks Sev. Is that a problem that will develop over time or something that would happen from the get go?

[Superdunc]

35 minutes ago, sev said:

I really don't know Del, the weak spark due to the configuration will be happening the minute you installed them, but as to the robustness of the system, I suppose that depends on the robustness of the components. @RonniB @Superdunc ?

Not sure to be honest Sev.

[alext]

Ok Ive bought a set of CBR600 coils, and will wire them up as described above when they arrive...

I can at least do the wiring while waiting for them.

so....

Any GSXR owners looking for a set of 4 stick coils??? £20 the set!

[alext]

6 hours ago, EXUPDEL said:

 

@alext when you put the sticks in the front cylinders of the vfr did you find the fan shroud hit the tops of them? 

my vfr engine is in a VF750!

it all clears (just)

[RonniB]

On 11/29/2020 at 4:55 PM, Superdunc said:

Not sure to be honest Sev.

The failure will be an accumulated load failure, like low heat and vibration, so it’s hard to say. A failsafe could be to run an ignition amplifier upstream, but then you just as well stick with old school coils

[dannn]

On 11/29/2020 at 11:41 AM, sev said:

Ok so the first question, which will give you some answers is how have you wired them?

**snip**

Hi Sev (, @alext @EXUPDEL @RonniB @Superdunc )

I've been in contact with Jiri at Ignitech and asked him questions in regards to the TCIP4 and coil on plug setups using your diagrams.

Jiri's response:

"Do not use parallel connection at TCIP4.

Use serial or separate connection. Serial connection can to use the same setting of dwell time as original system with two coils. Separate connection need shorter dwell time. See picture below.***"

I then asked a Jiri a further question - I believe from reading the TCIP4 documentation that IC3 pin 2 and IC4 pin2 11 are not connected as standard. Do I need to enable something in the software so I can use these with separate connection setup - standard ignition pickup and 4 X coil on plug ?

His response is what I've always thought would be the case if you use a single ignition pickup:

"If your unit has inscription 2CH or STANDARD - this unit has only two ignition outputs. This is not possible to solve with software. There are not output transistors."

So with a standard 2CH TCIP4 with a single ignition pickup the only option you have is to wire the 4 x coil on plug in series just as with a standard CDI (4 x wasted spark setup). The 919 Fireblade engine in my FZR run this setup and to date I've not had any weak spark issues ( dyno https://www.youtube.com/watch?v=e_OT0mPoTvk / track https://www.youtube.com/watch?v=wAxkp-afZ3E ).

If you have 2 phased (i.e. 180 degrees) ignition pickups ( VFR750 / 90 degrees ?? ) then you can use separate connection (one coil on plug per channel) setup. I assume the two internal coil drivers are being hooked to pairs of channels depending on which pickup caused the trigger (2 x wasted spark setup) which is sort of similar to DCCDIP2.  *Do note I don't know if the settings below are applicable for this setup or just if your using a separate connection 4CH TCIP4 single ignition pickup setup.

If you look on Ignitech's web site product page for the https://www.ignitech.cz/en/vyrobky/tcip/tcip.htm you see "SPARKER TCIP4 ignition is 2-channel and without driver for servomotor normaly. 4-channel version with servodriver is possible on demand.". I assume this special order version would allow separate connection - one channel per coil on plug but using the single ignition pickup being connected to both pickup inputs (CKPS1 and CKPS2). I wish I had realised this when buying the TCIP4 and got the upgraded four channel version!

Hopefully that clears up and clarifies what coil on plug setups can be used with a TCIP4.

I also have some info regarding the DCCDIP2 / DCCDIP4 which is related but will put that in a separate post or thread of its own.

Dan 🙂

*** separate connection - one channel per coil on plug settings:

Edited February 3, 2021 by dannn