oyvindjs

iTrader: (4)

Hi! I went on the look for some decent and sensibly priced coils for my setup as my stockers ws bust... So, after some reading, i found the yukon coils. Bought em and got the package... After some reading, i found that theese coils had built in igniters, and the FD allready has an igniter... So, i did some mental headsmashing and had a search on how to hook up theese coils. Found this thread by alex rodriguez, but his pictures has been deleted so i had to go out from what he had written.
thread here:
Going from Electromotive TEC3 to Power FC now got some questions. - RX7Club.com

He said:

From what i see of posts around, and from what i understand from the alex R thread over, and this thread( Megasquirt Sequencer Coils) the coils i have have built in igniter, I really hope this is true! Tried messaging alex about getting the pics back up, but no luck...

So, i cut the stock igniter off, and found the above mentioned cables, crimped on connectors and prepared em for the rest of the wiring:


I then took my 4 wiring looms, one for each coil. The connectors i built are pinned like this setup:


When taking a CLOSE look at the connectors i bought, they are labeled ABCD where the connector pins slide in, so i KNOW i have this part right.


SO, i paired up all the A-pins to one large connector, ground.
Paired up all the D-pins to one connector, 12V , this will go to the black/white 12v power cable that went to the igniter
WILL pair up all the browns and ground them too
I am then stuck with 4 white ones. They will be paired up with the 3 cables left in the igniter harness. TWO leading goes in on the leading cable connector and then one for each trailing, according to alex R thread.



Ok, here are my questions...

1. This coil DOES have a built in igniter, right? From what i read, the non-igniter coils have 3 pins, while the igniter-coils have 4. This have 4

2. Is my logic and thinking correct regarding the wiring?

3. How will the two pins in one leading/solution work? Does it work as a waste-spark and automaticly choose the right leading to fire, or does it fire both leading regardless? Is this correct to do? Do i have to set this up in the pfc?

4. Do you see any major flaws here?

C. Ludwig

iTrader: (27)

The Yukon coils are not a good fit for the wastespark application. They require a relatively long dwell time to produce a hot spark and they have been shown to auto-discharge as an over-charge protection "feature". What this means is the coil can decide that it is saturated and needs to discharge and when it does this it will be before the ECU tells it to discharge, which means you have the potential for uncontrolled ignition advance. Not what you want hooked to your rotary engine. We used to recommend these coils for direct-fire applications, but after seeing auto-discharge at work, we no longer will use them.

Forgetting all of that for a moment, these coils want around 6ms charge time to produce a good spark. With a wastespark setup you're at 80% duty with only 3 ms charge time at 8000 rpm on the leading coils. This is why these coils are not ideal for a wastespark setup on a rotary.

If you're still going ahead with it, wire them like this:

Coil Pin

A - power ground, should be grounded directly to the top of the rotor housing
B - signal ground, can be grounded to the chassis
C - ECU trigger (see below)
D - switched 12V+ (use a relay to switch fused power directly from the battery)

Connect pin C of each coil to the appropriate wire before the ignitor.

L1 and L2 - light green
T1 - brown
T2 - brown/black
The black/white wire can be used to turn the relay on/off. Do not use it to power the coils. Although your thinking is correct, this circuit isn't up to the amp draw these coils are capable of.

gxl90rx7

iTrader: (1)

do you have any documentation on the auto-discharge? do you know if it is a function of dwell or coil temp or ??

oyvindjs

iTrader: (4)

Ok. So if Im to go Ahead with this, whats the chance of engine failure? I thought these were good **** :-( Im going full seq BNR at 21psi with all surrounding mods and waterinjection.
What coils are recommended? Mercury coils? Arent they at 3ms dwell or something?
About wiring, i will do as you Said and use the ecu 12v to power a relay same way as i did on the fuel rewiring.

Are these coils usable if i go another ignition route? What then? Cost? Pfc compatible?

HELP!

thewird

iTrader: (8)

Get rid of those coils and put in some AEM smart coils. Why people get rid of the stock coils when they're good for 500 rwhp without the twin power is beyond me. Guess people like hacking up their wiring.

thewird

oyvindjs

iTrader: (4)

My original coils were bust....

C. Ludwig

iTrader: (27)

Documentation? No. Personal observation and observation of pros whom I respect, yes. There is also anecdotal stories of issues with these coils in the popular RX-8 kit.

The issue seems to be dwell related, but also seems to vary one coil from the next. Certainly high duty cycles and the heat generated aren't doing you any favors.

The fact the coil needs a relatively long charge time and the associated high duty cycle on a high rpm rotary running in wastespark is enough reason not to use them.