Ignition coils or other methods. Preferable COP

Discuss which Sensors work best with these ECUs and share how you are using inputs and outputs
Post Reply
Fredrik
Posts: 25
Joined: Thu Sep 29, 2016 2:01 pm
ECU Model: P8 Pro

Ignition coils or other methods. Preferable COP

Post by Fredrik »

I have spent hours of searching and didn´t come up with much.. The search function on this page don´t seem to work any good ether. I tried search for coils, ignition coils etc in topic subjects only and it was just to common of a word.. Tried different things but gave up.

I have an old p8pro in a project car with a honda b series turbo engine mapped to 600hp. It´s been in the works for like 15 years since I have been working on others cars as a part time business. I want to get it on the road before I start upgrading to a newer ecu though.

I use 4 msd 2 wire coils today and just drives them with a dwell time. (dumb coils)

Due to not having a lot of space I would like to switch to a COP type of coil but i don´t want to sacrifice any power. In the honda world people seem to run coils from the k-series engines that has 3 wire inputs. As I have found out they are connected to 12v + and - and the third wire is a 5v trigger. I don´t know much more.. In Hondata software which is like the stock ecu you still have to enter a dwell value for those coils and as far as I can find out it also is a 5v trigger. Then it must be some sort of signal to tell the coils how long to charge. And I guess when the 5v trigger or dwell signal ends it fires the spark?

Is this how most 3 wire coil on plug coils work?

The DTA p8pro software I can under "general engine settings" check external coil amps.. As I understand it I just invert the grounding of the ignition outputs of the ecu to +12v output?

How do I set this up to trigger the k series coils with a 5v signal?

Anyone have a tips on rely good coils to us? I talked to a drag racing guy making like a 1000hp on a k series honda engine. He switched from the k series coils to a M&W mercury magnetic something ignition system and said that he gained something around 50hp.

My car on the other hand is a street, circuit, drag car in that order so I want everything to stay together more then 402m.

I don´t realy know how a CDI box is working I might be missing something..
Alex DTA
Posts: 1622
Joined: Fri Feb 28, 2014 1:03 pm
ECU Model: S40 Pro
Distributor: DTA
Firmware Version: 79

Re: Ignition coils or other methods. Preferable COP

Post by Alex DTA »

The K Series coils are amplified. They work fine with the 12v signal from the P8, but you do need to use a 1k pull up resistor to make them work.
Fredrik
Posts: 25
Joined: Thu Sep 29, 2016 2:01 pm
ECU Model: P8 Pro

Re: Ignition coils or other methods. Preferable COP

Post by Fredrik »

Easy as that was what I hoped for.. Many thanks..

Doesn´t you use a resistor to pull up or down so the output doesn´t float?? So the coil gets a consistent signal?

A pull up resistor wouldn´t it keep the signal to about 12v all the time and since the 12v signal output from the ecu trigger the coil to charge, wouldnt that be wrong?

Is it a pull down resistor you mean? to keep the signal close to ground while the ecu is NOT triggering?
Alex DTA
Posts: 1622
Joined: Fri Feb 28, 2014 1:03 pm
ECU Model: S40 Pro
Distributor: DTA
Firmware Version: 79

Re: Ignition coils or other methods. Preferable COP

Post by Alex DTA »

No, it's definitely a pull up resistor. Here's the diagram:
http://www.dtafast.co.uk/download_files ... Pullup.pdf

The pullup isn't there to prevent float, as the output isn't directly connected to the microcontroller.
It's there to alter the resistance across the coil driver output so the coil driver can see there's a coil attached.
stevieturbo
Posts: 3577
Joined: Tue Aug 02, 2011 12:08 pm
ECU Model: No ECU
Location: Norn Iron

Re: Ignition coils or other methods. Preferable COP

Post by stevieturbo »

Dont some old Honda stuff run theirs inverted ? Or is that only the coil in cap stuff ?

ie when any normal ecu would be charging the coil with the "on" trigger.....Honda is off. So you can accidentally get into a state where you overdwell the things and burn them out ( not that I'd ever do such a thing LOL ) although that was a B16 dizzy/coil in cap type.
Alex DTA
Posts: 1622
Joined: Fri Feb 28, 2014 1:03 pm
ECU Model: S40 Pro
Distributor: DTA
Firmware Version: 79

Re: Ignition coils or other methods. Preferable COP

Post by Alex DTA »

Dunno, but the K20 coils are "normal" amplified.
Fredrik
Posts: 25
Joined: Thu Sep 29, 2016 2:01 pm
ECU Model: P8 Pro

Re: Ignition coils or other methods. Preferable COP

Post by Fredrik »

Thanks for the replys.. I now know that I can use the k series coils with ease on my b series setup.
Post Reply