[lucasanderson]

After perusing the source code, it looks like everything is already set up for a sequential 8 cylinder setup and only hardware changes need to be made. Am I wrong in this assumption? It appears that adding injectors 6,7, and 8 replace the pins on the Mega for ignition outputs 4,3, and 2. If anybody has some input on this I would greatly appreciate it.
Thanks, Luke

[lucasanderson]

Update: My initial idea wasn't correct. For those wondering, I was able to add a new board definition (based on v0.4 "case 3") to reference/speeduino.ini, and also to init.ino to change my pin definitions. I took over the pins for ignition 2, 3, and 4 which leaves me one ignition output if I want to add some distributor timing control in the future. I was able to compile and upload that successfully and was able to select my new board in tunerstudio.
Next I'll test the Mega to make sure that it's actually "firing on all 8". After that is the board design.
If anybody has feedback or knows a better way to swap pins around please chime in!
-Luke

[PSIG]

Just curious if you considered using the HC outputs (v0.4 D4, 6 &7?), so existing hardware could be used instead of a new board design?

What application do you have that will benefit from full-sequential? Do as you like; I'm just curious.

[lucasanderson]

Hi PSIG, the application is a big block Chrysler with tunnel ram set up for drag racing. And yes, that's a good idea to just use those other outputs and add on another board with the injector drivers. I'll also have security and widebands in the mix as well. I guess one of the things I would like to avoid is building a box stuffed with a bunch of different boards and jumper wires, so a quick board redesign to add and subtract the things I want will probably be the nicest end result.

[MosFetMan]

I'm so glad I found this thread! I just ordered 5 of the Pazi88 0.4 boards intended for the BMW MS41, a 6 cylinder inline. I hope to make it work on a Jeep 4.0l 6 cyl inline. The waste spark/injector is driving me insane so I much do as you did; find some unused pins, mod the S/W , and add whatever H/W I need to achieve sequential firing.

[jonbill]

The cylinders (and the combustion in them) don't know or care how many squirts it took to get the right amount of fuel vapour in the inlet tract, ready for the valve to open and let it in.
Making it work sequential sounds like fun, so why not, but I reckon there are only advantages over paired in some very specific circumstances.

[lucasanderson]

MosFetMan, sounds like an interesting project. If that board has 6 cyl sequential and 6 cyl cop as a capability then I would definitely figure out how it works rather than going the route I am. Hopefully I didn't trivialize the process of modifying the firmware and making a new board.

As far as sequential is concerned, I'm surprised there's not more support in this community. It was the industry standard 20 years ago, now mostly eclipsed by DI. Besides, the logic in Speeduino firmware has already been developed up to 8 cylinders and is ripe for the taking.

[punisher454]

The STM32 and Teensy variants can do full sequential injection and ignition (8X8). The the mega256 based "standard" speeduino lacks the the number of timers (Or at least thats my understanding).
In My case the desire for for sequential injection on a V8 is mostly for individual cylinder fuel trim capability. Not a big deal on stock type engines which is probably something like 95%+ of the speeduino instalations, but for something thats a lot higher output with the VERY real potential of self harm due to just having one hole a little lean, its worth it. Of course you need to tune with multiple widebands to get all eight dialed in evenly.
A little side benefit may possibly be a tiny bit better idle control, but thats not the real main benefit. horsepower wise you'll make the same peak power with full sequential as you would batch fire.
Even with a Tunnel-Ram, on a V8 you will have uneven airflow from one cylinder to the next. Part of the problem is adjacent ports in the manifold disrupting airflow depending on the firing order and runner enterance placement. A wideband in a header collector is just an average of the cylinders feeding it. Once again, on stockish mild cam engines this isnt a big deal and they dont vary that much. But with more cam, displacement and compression, you start to see the effects of runner length and port design become more and more significant. Add on high boost and heat running right at the detonation limit of whatever the fuel is being used, and it becomes worthwile. At least, thats what I think.

[NickZ]

My question is also why? There are already a dozen plus boards that already support 8 x 8 sequential for a v8, I drive one daily.
Maybe you haven't seen them?

[lucasanderson]

Why? Uhh because it's fun and I like building things?