Harlan

iTrader: (3)

Can't make the IGN-1A coils work for ion sensing. So Isuzu coils it is. Trying to use the Isuzu knock module.

This mod hinges on a few things:
1 Coils can be fired on independent timing for leading/trailing vs 6 cylinders (Seems to be a 5v input to dwell each coil individually)

2. Coils are not wired for wasted spark. (It appears that the Isuzu ecu uses wasted spark but the coils are independent...)

3. It has a usable Ion Signal. (No clue. It has a knock signal and a combustion quality signal. Combustion quality may be raw ion signal... don't know yet. Need bench testing)

4. It can register rotary knock. (Not a requirement if it has a usable ion signal, but if it can read knock that far outside the normal frequency it would be a great addition and would simplify things a lot)

5. It can handle high RPM for long duration. (The driver/coils may not handle 9000RPM firing every rotation for long. Again need bench testing.)

If all this works it would make it reasonable to make a kit for use on other cars. We'll see.

Harlan

iTrader: (3)

Wasted a day attempting to 3d print connectors for the Isuzu ion sensing module, and then couldn't get it hooked up and working right. Now I've bought a Isuzu wiring harness and am waiting for it to arrive so I can get everything hooked up.

Also looking at Ford fuel pump controllers.

Waiting for actual results to post more.

skc

I was going to upgrade to 1GN-1A coils. This is the first time I have seen someone having failures. I am confused now on which coils to use.

Harlan

iTrader: (3)

IGN-1A are great coils mine have had no problems. My problem is with a set of IGN-1 coils I got as well, which are similar but have no internal ignition.

Unless you were specifically looking for them you would not get the IGN-1 coils. If you want a used set of IGN-1A coils let me know, I got a set I don't use anymore and while not pretty anymore are still great coils.

Harlan

iTrader: (3)

Killed my first Isuzu ignition module while testing coil dwell settings. It has a much shorter dwell compared to the stock Rx8 and most other coils. At dwells <1ms it appears to internally limit to a shorter value. Above about 200microseconds there appears to be no change in spark intensity.

I tried running a continuous spark and killed it at 50microsecond dwell and 1000microsecond firing time. It's now completely dead. Dunno how it died, did not appear to overheat or run too much current. Most automotive hardware is fairly robust, but it didn't like something I did.

But before it died it did give me a few bits of valuable information. The coils can be fired independently, the dwell is radically lower than stock, and I have the correct pin out for the module.

What I still need is a proper dwell, that is the dwell where the module will not fire early due to internal limits. I also need to test the knock and ion signals out, and find out the format. Specifically analog or PWM and if PWM then the frequency and duration.

skc

I am looking to buy a kit that is more reliable. However, I am also looking to relocate my coils to the chassis rail to stay away from the heat generated by the supercharger.

Reoze

How is the teensy working out for you? Are you controlling the ignition coils directly off the GPIO? I couldn't even make a proper LCD driver for these chips because their GPIO switching rate was so low, so I'm a bit surprised you're having such a good experience with the chip.

If you ever hit the point where you want to start looking into more serious microcontrollers I can definitely recommend an NXP LPC176x (Cortex-M3). Extremely high GPIO resolutions, DMA, etc. Has a built in CANBUS peripheral controller too

Harlan

iTrader: (3)

No problems with the IO on the teensy, I have a timer set to trigger every degree and then read the ignition input and write an output to the coils. It's been bench tested to 10krpm and road tested to over 9k. Doesn't miss a beat.

Currently sticking with the arduino ecosystem because it is what I know, but may eventually get a bit more brave.

Reoze

That's pretty damn impressive for a teensy. You're making me want to try this on my car now. Too bad I know nothing about ignition timings. Time to start reading.

Harlan

iTrader: (3)

I was going to try it first on a arduino, but I worried about all the math required for the control function while maintaining real time on the ignition.

After I had mapped the trigger wheel to a pin on an interrupt I created a routine to decode it and set the position to match each tooth as it passed by. Then I created a timer to go off each degree in between. This made an easy 0-359 deg representation of the E-shaft.

Once I had that I mapped the original ignition signals to 0-359deg arrays. I then could play back the original arrays at offset to change my timing.

It worked like a champ and the critical stuff was interrupt driven.

Reoze

I suppose that would actually work pretty well. The latency becomes much less relevant at that point. As long as the ports can switch fast enough at 9-10k RPM that's all that matters. You're just doing the timing at this point right? Any plans for the air/fuel system? Seems like that would be considerably harder as it's less deterministic and linear like the RPM/timing tables would be.

Have you considered any type of redundancy on the controller level? Just in case it got wet or cooked for some reason. I'm curious if a failover could be set up quick enough that didn't impact engine timing. You could probably alleviate most of the environmental concerns by dipping the entire thing in epoxy though.

Harlan

iTrader: (3)

Isuzu ignition coils might be a bust. The module sends a 45hz PWM signal for both ignition quality (missfire) and knock. Much too slow.. Still testing.

Harlan

iTrader: (3)

Ok, Isuzu modules give a pulse (rather pull to ground briefly) when each coil is fired. I was having a devil of a time getting data though because of EMF. So 45hz is not accurate, it is a frequency determined by rpm.

I don't think I'm going to use the Isuzu ignition module coils because there are too many unknowns at this point and the short dwell time is a pain in the butt.

And I'm back to having no usable ignition coils for this build. Looking for options.

Reoze

Found this, might help.
Megasquirt Sequencer Coils

Covers D585 coil wiring which should be compatible with the stock RX8 coils At least that's what I heard the BHR kits are based on.

Seems fairly simple, 12v supply, two grounds, and pull the 5v high for spark

Also came across this if you were interested in making your own coil driver.
http://www.st.com/content/ccc/resour...CD00286281.pdf

Harlan

iTrader: (3)

I need ignition coils with a measurable secondary resistance (continuity on the secondary) so I can use ion sensing. Most ignition coils either have the secondary ground common with the primary ground, or a blocking diode on the secondary.

D585 coils have a combined primary/secondary ground. IGN-1A coils have a blocking diode. So far I've only found the Isuzu coils (with the ridiculously low dwell) and the IGN-1 coils (which burn out on me). So right now I'm up poop creek watching my paddle float away.

I'm about to buy another set of IGN-1 coils unless I get another idea soon.

That looks like a nice coil driver chip. I've used plain mosfets before but with no current limiting they go pop if you exceed dwell limits.

Reoze

Ah yeah I just started watching your videos after my last post, everything makes a bit more sense now. Did the ion sensing do much in the end? Obviously it was providing data, but i'm sure you have an idea of how valuable it was in the end.

Harlan

iTrader: (3)

I'm not sure if I'll ever get a usable PPP for maximum torque, at least not at high RPM. I'm not giving up on it though.

I have gotten crystal clear detonation indication at ALL rpms though, and that will give me quite a bit of safety margin in boost. It should easily retard timing on the fly for maximum safe timing.

Harlan

iTrader: (3)

Just put a video up about my ignition coil problems. Waiting on the new coils.

Reoze

Forgive me for being ignorant here, but from what I've been reading, if you detonate once, your engine is toast. Is that a bunch of FUD? Or is what you're detecting conditions just before detonation?

Harlan

iTrader: (3)

If you can hear detonation the damage may already be done, but low level (mild) detonation is harmless and very difficult to hear.

Also because of electronic ignition control detonation may only happen at high load where it's hard to hear over engine noise.

This is why a good detonation sensor is crucial with these cars. Otherwise you are flying blind until bang.

Harlan

iTrader: (3)

I did a bad, very bad, incredibly bad thing. While testing the ignition coils I set my piggyback to fire each coil once per second so I could test without cranking the engine. Then a week and a half later I replaced the coils and tried to start it.

It did not start, and acted like I had spark plug wires reversed. So I checked all the wires multiple times until I remembered what I had done.

The engine bucked a couple of times as it tried to start... Don't know if there is any damage, but it runs fine.

<sigh> Don't be stupid.

Brettus

iTrader: (2)

If it makes you feel any better : I went out and did a series of SSV timing before and after tests last night . The results showed no differences which left me scratching my head . This morning I discovered I had reversed the plugs to the SSV several days ago (to test something else) and forgot to put them back in place for the test.

Harlan

iTrader: (3)

Here is a video about the "incident". Didn't catch the actual attempted start on video, nor was I going to recreate it for the lols. Oh and purple hair.

Harlan

iTrader: (3)

Haven't had time to do much. I'm thinking of ditching the PPP sensing and just use ion sensing for detonation detection. It's a step back from what I wanted to accomplish, but I don't think I have time to get it right. I believe I can get almost as good a result with precise detonation detection, I just won't be able to see when the timing is too advanced at lower loads without looking at other indications.

Also because I'm short on free time I've done a Q and A video. If you guys have any questions about the build or anything else I'm doing feel free to ask.

Harlan

iTrader: (3)

I finally answered everyone's burning question, why no intercooler?