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-   -   Turbo 13b ignition (https://www.rx7club.com/general-rotary-tech-support-11/turbo-13b-ignition-1097227/)

MATCOGLEN 03-07-16 03:30 AM

Turbo 13b ignition
 
hey everyone new here. want to know if anyone has the wiring diagram from the electromotive tec2 for the 2 ROTARY FUEL INJECTED .

Placed engine in a new sand rail and a few of the wires had come loose from the board it have the 4 coil packs . If anyone could help it would be AWESOME!!:nod:

MATCOGLEN 03-07-16 07:38 AM

https://cimg4.ibsrv.net/gimg/www.rx7...2ede50d0c.jpeg


This is the ignition I have

Aaron Cake 03-12-16 10:18 AM

Um, what I see there are 4 waste spark coils, for 8 total plugs. Is this going onto a 4 rotor with zero split?

What standalone are you driving it with?

MATCOGLEN 03-17-16 05:48 PM

It's a 2 rotor 13b turbo fuel injection. I have spark and seems that the fuel injectors aren't firing off now. I'm new to the rotary world what is a stand alone exactly?

Aaron Cake 03-19-16 10:24 AM

Standalone = electronic engine management system

Do you have a Tec2?

Without knowing your setup, I'd say those are the wrong coils for a 13B.

The typical 13B runs waste spark on the leadings, then individual coils on the trailings. Or more recently, 4 individual coils, one per plug.

You have 4 waste spark coils. That's a setup for a V8 or 4 rotor without trailing split. Only one of those coils would be useful for your 13B.

MATCOGLEN 03-19-16 11:51 AM

It is the electromotive Tec 2 from my knowledge. I bought the engine running on a sand rail when the previous owner took it out of his rail some wires came loose, now tracing the wires they ones that came out don't seem to be running to any of the sensors or injectors. I have spark when cranking. I just don't know much about how the system works .

Aaron Cake 03-26-16 10:28 AM

I don't know how those coils could have been used on a 13B. They aren't the correct coils. Might be worth asking the previous owner.

j9fd3s 03-26-16 02:53 PM

since those are coils for waste spark, and you're not running waste spark, the second plug wire on each coil just gets grounded to the block

MATCOGLEN 03-26-16 09:58 PM

The previous owner doesn't know anything about this system have asked several times . Rotary shack in California built this engine along with the setup for ignition .

Aaron Cake 03-27-16 09:55 AM

That cannot work very well. Grounding out a wastespark coil is not the same as it sparking...waste.

Perhaps contact the shop that put it together?

Or, well, I guess you will need to look up the wiring schematic for a Tec2 and then determine which coil goes to which plug based on the wire triggering it.

Then switch to single ended coils.

peejay 03-28-16 06:10 PM

Believe it or not, that is the way Electromotive did it.

Fiction has to be plausible, but history merely has to be true.

Speed of light 03-29-16 12:19 AM

Grounding a waste spark coil to run it single ended is perfectly acceptable. Single ended coils just have the ground wired internally; it makes no difference to performance whatsoever. The electrons don't care one way or the other so long as there is a circuit.

BTW, those are good coils--I've personally tested them and wouldn't hesitate to use them. They had the 2nd highest current output of all the coils I've tried.

Aaron Cake 04-02-16 09:55 AM

Impedance of a dual ended coil is going to be far different than a single ended coil. The impedance curve of a spark gap is basically the opposite of a solid conductor (to ground). Still, I didn't say it wouldn't work, I just said "it can't work very well". :-) The coils may be designed to handle this configuration.

In that case, it's up to the OP to determine which coil is which. Look up the rotary wiring for a Tec2 and then determine which wire colour from the ECU fires which rotor.

Speed of light 04-02-16 01:11 PM


Originally Posted by Aaron Cake (Post 12046740)
Impedance of a dual ended coil is going to be far different than a single ended coil. The impedance curve of a spark gap is basically the opposite of a solid conductor (to ground). Still, I didn't say it wouldn't work, I just said "it can't work very well". :-) The coils may be designed to handle this configuration......

There is no difference between the two. Yes, the double ended coil is firing two gaps in series, however, they are not equal. Once the wasted spark gap ionizes, its effective impedance becomes very low and all of the action is at the plug under compression. The voltage drop (hence the impedance) across the wasted gap is negligible keeping in mind its not under compression pressure; so it really just acts like a booster gap or similar to a distributor type system whereas you have an extra gap in the cap. I have several oscillograms I took of this effect--I'll see if I can find one to post--in any event, affect is minimal. That being said, there are some single ended coils that are grounded internally through a series 'damper' diode, which helps suppress ringing, but doesn't otherwise change its performance.

The impedance of a coil is going to primarily be determined by two factors: its turns ratio and its load--the wire, spark plug and spark conditions--being reflected back to the primary as the square of said ratio. As a guide, the coil depicted in the above post is about 70:1, favoring high current (similar to the Merc/AEM coils, iirc). OEM FD coils are 100:1; a typical value. The fabled FC coils are about 120:1. These are all measured values. The latter FC coil will favor large gaps under heavier loads--if the system is good enough to hold the extra voltage--but will deliver less current and heat in the process.

Aaron Cake 04-03-16 09:39 AM

Meh, whatever. If it works, it works. Going back to my Tesla coil days when messing with wasted spark coils in the primary, outputs were always lower due to the coil not expecting a constant ground, instead expecting to see the high impedance plug initially then drop to a short. Primary drive current of the coil also went up considerably because half the secondary was in direct short, lowering output of the other side of the coil.

I'm going to stand by my recommendation to switch to single sided coils.


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