Fen

This thread is spawned from the OT discussion on the control arms thread.

Basically I have a standalone system (Autronic SM4) running with the stock coil through a Bosch ignition amplifier. I'm already running fully sequential injection and the EMS is capable out of the box of running anything pretty much; wasted spark, CDI, you name it.

I'm trying to learn fast on igniton but I have a way to go. The EMS dealer has a wasted spark system he's really excited about and it's cheap, but the guy who built the car says he thinks CDI is the way to go. I don't know enough about the likely extra cost of CDI and if it's worth it. I want to get the right system straight away rather than go for wasted spark and then want to upgrade again ina few months.

Advice more than welcome then...

NZ951

Sorry from the other thread...


Well EVO's use a wasted spark setup stock, so its not much of an achievement getting that working lol. For the Link I have, its basically a dual channel igniter, 2 X dual post coils and you are done. You should only need the cam hall effect sensor if you are gong sequential, remember your ECU knows the firing order, so wasted spark does not need anything else.

Fen

I already run sequential injection so I need my reference sensor, and the triggers are working fine up to the 7,000 rpm redline I have chosen.

I think what you have is the system the Autronic dealer is suggesting - my igniter is a dual channel already (just using one for now) so I only need the dual post coils.

When I searched on here a wek or two ago there was a lot of discussion about the merits of CDI over that setup and before my head got hot and I had to lie down I wasn't sure there was a conclusion. I think part of the negative of CDI was that the thread was relating to cars running Motronic so there was a lot of electronics needed to drive it. I already have the electronics (and here is as good a reason to go standalone as any; I bought one expensive-ish box and it runs sequential injection, sequential ignition, EBC, plus loads of other stuff like launch control, WOT shifting, anti-lag etc. etc. and of course they are all compatible as they run from one computer as well as much cheaper than a load of dedicated boxes like EBCs) so I don't know how much more expensive it would be for me to use it, nor even if there is a real-world advantage to be had. I'd like a big spark to help with my minor plug fouling problem for sure.

NZ951

Ah ok if you already have the cam hall effect sensor, then just get a 4 channel igniter and 4 coils (something like the SR20DET)... and you are rocking.

NZ951

Keep in mind when you have a high performance ignition setup you are more prone to detonation, so you will likely need to retard your timing.

Fen

That's a good point - don't want to have to restrict boost to allow for the ignition system.

Is the SR20DET setup 4 coils with HT leads to the plugs then? That sounds like a nice compromise as each coil gets twice as long to charge up as in a wasted spark setup.

NZ951

You will still make the same power with a high performance ignition, just with less timing. Yes thats how the SR20DET is setup. Can you trim each individual cylinder? You would need sequentional ignition if you do want to go that route...

Fen

I can trim individual cylinders, yes.

The reason I say I don't want to have to restrict boost is that it looks like we will run out of ignition retard even now if we add much much more (currently it's injector duty cycle that is holding us up but more fuel pressure will fix that as it's the stock regulator just now).

I'm liking the sound of the SR20DET system but I see an upgrade for that engine is coil on plug, which is obviously something for me to consider, especially if it is "better". Assuming I can get coils to fit the 951 plugs.

NZ951

Oooooh coil on plug would be sweet

NZ951

PS I think the RB20DET uses a coil on plug factory... that may be a cheaper option to look for.

Pauerman

Fen,

If your Autronic box doesn't have ignitors built in, take a look into using 4 GM LS1 coils for a "coil near plug" configuration. These coils have the ignitor built into the coil and are rated at 80-90 mJ of spark energy. This is a pretty clean option that can be easily installed with simple bracket. Add some Magnacore KV-85 wires cut to length with the appropriate boots and you're set!

If your SM4 does have an ignitor feature, just look into using 4 "dumb" coil packs (Bosch style) also set up in a coil near plug - same Magnacore option.

If you're set on CDI, take a look at some motorcycle coils. This seems to be a popular option for the import guys using AEM EMS' and CDI boxes. The Suzuki GSXR coil sticks will work on our cylinder head and M&W Ignitions sells a 4 channel CDI box (Pro-14) that works well with the MC coils. This is a pretty expensive option @ $895 plus an extra $50-100 for the coils & harness. Considering that the spark energy output of this CDI box running sequentially is 105 mJ, it's hard to justify this type of expense considering that an inductive coil pack arrangement will be up to the task and cost much less. The one feedback note I've been told is that CDI boxes emit a lot of electrical noise.

Take a look at the Motec catalog - they list LS1 coils and some results they've achieved with them (2000hp V8 @ 20 psi). These are, in my opinion, the cheapest and cleanest coil option for running sequential ignition. I'm going to be using these coils with my AEM EMS - based on much feedback from guys with high hp applications, I'm told that this coil set up will work well. If you're interested, I've got an extra set of 4 with the wiring harness.

HTH
Vic

Fen

Thanks Vic, it helps to a point but I still struggle with some concepts. I think I'm starting to see that CDI is possibly not the way to go. I'm certainly not set on it, in fact I'm not even clear what its advantages are supposed to be.

I have a spare Peugeot engine in my garage with one of its big-end bearings spread pretty well right through it. When it failed I just put another engine in the car so it's never going to be rebuilt, more likely stripped and parts sold. I'm already using the TPS from it and it has coil on plug ignition. What's involved in making that work beyond physically getting the coils to stay on the plugs in the 951 head? I don't really know what fires the coils in the Peugeot I guess as it's the newest/most advanced petrol engine I have owned.

I don't believe the SM4 has igniters built in. It has 8 outputs that can trigger igniters such as I'm using with the Bosch amplifier to run the OE coil just now, but they need the amplifier to work.

Mike S

Sorry, don't want to pull this off topic....but how was the install of the Autronic? Do your dash gauges work? Any problems or drawbacks so far?

Fen

Boost gauge doesn't work but the rest are fine.

Because it's using sequential injection it needs a cam reference sensor which we fabricated using a strip of mild steel attached to the cam pulley and a 964 crank sensor through the inspection hole in the dizzy cap. I might make that better when the dizzy is deleted.

It can't use the 132 teeth on the flywheel nor the grub screws as it needs 2 crank sensors minimum 180 degrees apart. We found that last point after the engine was in so we fitted a hall sender (Honeywell GT-35 which was cheap and perfect for the job from RS Components) and 2 lugs on the back of the balance shaft drive pulley.

Other than that it needs a 0-5v TPS so I used the Peugeot one on an adaptor machined from perspex of all things.

Last problem is that it you need to make up a loom to suit. It wasn't too hard with heat shrink, a good soldering kit and a few new Bosch plugs.

In terms of drawbacks there are none so far (I knew the boost gauge would not work) aside the PITA jobs listed above. In terms of advantages it runs sequential injection using pretty much any injector you fancy. It also manages boost through Autronic's solenoid and it will do WOT shifting when I get a microswitch on the clutch pedal, launch control when I connect up the speed sensor and anti-lag when I connect the EGT sender. It really is a good EMS - Autronic was set up by ex MoTeC guys after a fall out of some sort a few years ago.

Fen

Oh, I also got a custom intake pipe made up (which worked out beautifully) but that was largely because nobody in the UK supplies them. I had it copied from my Autothority MAF but obviously it's just a pipe as the Autronic runs MAP.