MoTeC Global Forum

Hello,
I'm totally new to motec, and am gathering all i need to start with the complete system.
So far i have on paper what i want, what i need, what i have, and still have to buy.

Now, the M800 has 6 ignition outputs.
I want to run wasted spark, but want to do this with 8 coils (a V8 Ford 460 engine)

At work i've ordered Omron Solid state relays of 10 amps each.
I want to drive 2 relays per one output, and have each relay itself switch a coil.
So, 2 coils are actuated on one output, and the output isn't overloaded by 2 coils.

Is this a good setup, or would anyone suggest to do this differently?
Don't know exactly how much current each coil would pull, so i thought 10 amps each would be more than enough.

What wire diameter would one use for coils, injectors, sensors, and other stuff?

Thanks!!

Rather than a solid state relay you need to use a transistor or IGBT designed for logic level signals on the gate such as this-

http://www.mouser.com/ProductDetail/ON-Semiconductor/NGP15N41CLG/?qs=sGAEpiMZZMtqO%252bWUGLBzeOCM7KMqh07G

Use one per coil and wire the gate (ECU ign output) parallel on paired cylinders, heat sink the transistor but keep in mind the TO-220 mount tab is also the collector so it needs to be electrically isolated.

As far as wiring plan on 10a-15a max per coil depending on coils.

A better option would be the IGN-1A coil with built-in transistors.

Might also look at the Chev LS2 Coils with built in igniters this way you just T the ECU IGN output to each pair.
(the coils are surprisingly cheap a Bud here in Australia bout a new set for $20 per coil for another project)

This is how I have my LS Chev wired in my car.

dutchie wrote:Hello,
I'm totally new to motec, and am gathering all i need to start with the complete system.
So far i have on paper what i want, what i need, what i have, and still have to buy.

Now, the M800 has 6 ignition outputs.
I want to run wasted spark, but want to do this with 8 coils (a V8 Ford 460 engine)

At work i've ordered Omron Solid state relays of 10 amps each.
I want to drive 2 relays per one output, and have each relay itself switch a coil.
So, 2 coils are actuated on one output, and the output isn't overloaded by 2 coils.

Is this a good setup, or would anyone suggest to do this differently?
Don't know exactly how much current each coil would pull, so i thought 10 amps each would be more than enough.

What wire diameter would one use for coils, injectors, sensors, and other stuff?

Thanks!!

You dont need relays etc.

Do the coils have built in ignitors or do they use an external amp ?

The Motec only switches low level outputs. So just pair up the relevant outputs into an ignition amp for each coil, and job done.

You may need 2 x 4 channel ignition amps for this, unless there is an 8 channel available.

for example. Motec output 1, to cyls 1 and 6 passing through the relevant ignition amps.

Likewise for the other 4 outputs, each firing 2 cylinders.

or as stated, use LS1 coils with internal amps, and again, just pair up firing pair trigger wires. Will make for easier wiring than using seperate amps.


ive heard people say you can pair up wiring after the amp to fire 2 coils. Although Ive never been able to get that to work.

ok, thanks.
i have to admit, at 20 bucks each, i won't go through the hassle and just use that.


that cheap??
are they any good then??

Can't say for sure as I haven't used them, mine are the Aus L98 coils.

This is the part number for the "cheap" coils.

Delphi number: D514A "these are LS2 coils"

GM: 12573190

As Scott pointed out these work exceedingly well:

http://www.034motorsport.com/ignition-s ... p-277.html

http://picasaweb.google.com/lh/photo/Qx ... directlink

Also why waste spark ? Get an ignition expander.

What would be the benefit of full sequential spark, compared to wasted spark then?
Note that my engine will never see 5500 Rpm's...

i checked some articles about the coils, and saw a neat video comparing coils. So, i have some offers running on Ebay right now

A ignition expander is nice, but when taken the cost in my head, i really have to be able to justify it in a matter for myself.

hey, when a multi-CD like the AEM comes in sight, there's a real cool additional advantage of a bunch of huge sparks, but, using active coils, w.s., VS $$ for seq. and/or CD, hmmm... i dunno.

As a newbee to ECU's, i think its not advisable to go the steepest route there is. Just start slowly and managable.

Speaking of which:

in a few weeks i go on holidays.
I always like to read a lot.
Are there any advices on downloadable PDF's or info that i can download and print, to get past the 3 weeks i've got to read?
Especially on the Motec M800 naturally.
Already bought some books from the links i found here.

Thanks.

Hello, here i am again.
As the rebuilt engine (that i bought as rebuilt) had some flaws, i needed to rebuild it again. Therefore the project was delayed a bit..

Now, all ECU questions come up again, and i definately want to go for the LS coils. There are however 2 types, and it seems that the D585 gibe a hotter spark.
As i intend to run propane only with a lean mixture, i have more use for a long duration powerful spark, as a short high voltage spark. (my Cr. is 10.5:1).

Still, sequential still buzzes in my head, but when i take a look at the ignition expander, i see that one channel still adresses 2 coils, which makes it wasted spark, not full sequential.
Do i overlook something?
What would i need to go full sequential, and what would be the real benefits compared to wasted spark?

Thanks for all the advices so far.

Any of the coils fitted to an LS motor will be more than enough spark for you.

Dont be worried about getting the D585, as they are getting hard to find second hand.

But plenty of the other types. They are all good.

But do not buy any cheap chinese copies. Whatever you buy, make sure they are the genuine product.