New here introduction, question, and also details.

FreeEMS topics that aren't specific to hardware development or firmware development.
Sam
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New here introduction, question, and also details.

Post by Sam »

Hey all,

Very excited about this project. I'd probably be more helpful with regards to hardware than software; I'm still learning a lot of coding. I think my current plan right now is to print my own PCB based on the Ravage schematics. My question is, I know that the current stated limit for sequential is 6 injectors, and 6 ignition... for a V8, is it possible to do 4 sequential injection channels, using paired injectors (so basically semi-sequential), and then have 8 sequential ignition channels? I drive a 2001 Dodge Ram with a 5.9L Magnum V8, and 46RE transmission. MPI, basically a perfect motor to use with this. I will probably have to fabricate or change some sensors, but otherwise FreeEMS is perfect for me. I plan on running two GT45 turbos in the future, stroking the motor to a 408 (6.7), and running around 20psi of boost or somewhere around there, to make around 1200hp (at least a grand at the wheels is my goal). The stock computer can't handle more than 5psi without freaking out, so I'm turning to FreeEMS since megasquirt is quite costly and closed source (always fun to be able to tell my friends that my truck runs on open source software and hardware, plus the bastards want $600 for a decent MS setup, why the heck should I pay that when I can make my own?). I'm majoring in mechanical engineering at the University of Arkansas and I love going to Tulsa Raceway Park in my free time. This is gonna be a drag truck before too long. So yeah, I'm Sam.

Thanks,
Sam
Sam
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Re: New here introduction, question, and also details.

Post by Sam »

TO ADD:

I'm wondering, though, if it's even necessary to want a sequential ignition setup. For a 1200hp 20psi 6.7L V8, how much precision is really needed past semi-seq injection and wasted spark ignition? If I can get away with less complexity and headache and still have a kickass tuned engine, then I'd be cool with running an EDIS setup with four coils and be done with it.

Sam.
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Re: New here introduction, question, and also details.

Post by malcom2073 »

Hi!

As far as I know, Jaguar is considered the most up to date, and is certainly the most tested design out there at the moment. You are probably best off basing your design off of that. You will also be limited to batch fire fuel injection with wasted spark ignition, as there are only 6 timer channels available for use (injection and ignition), as the code does not support full sequential on more than 4 cylinders.

If you do design your own board, you should design it to support sequential for once support is available, but also allow it to be jumpered for semi-sequential (see Jaguar, as it does this). Sequential will get you better transient throttle response and more controllable fuel at idle, so not really needed on a drag race engine, but it's not complicated to support in hardware.
Sam
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Re: New here introduction, question, and also details.

Post by Sam »

malcom2073 wrote:Hi!

As far as I know, Jaguar is considered the most up to date, and is certainly the most tested design out there at the moment. You are probably best off basing your design off of that. You will also be limited to batch fire fuel injection with wasted spark ignition, as there are only 6 timer channels available for use (injection and ignition), as the code does not support full sequential on more than 4 cylinders.

If you do design your own board, you should design it to support sequential for once support is available, but also allow it to be jumpered for semi-sequential (see Jaguar, as it does this). Sequential will get you better transient throttle response and more controllable fuel at idle, so not really needed on a drag race engine, but it's not complicated to support in hardware.
Well it sounds to me like Jaguar is my best option then, again, I just want better control and tunability than my stock ecu, which I BELIEVE is using batch injection with pairs (so semi sequential I guess) and a dizzy. I get like 12-13mpg average if I baby it, 15-16mpg highway.. It's a 6400lb pickup so not surprising I guess. Should change once I go with FreeEMS and electric radiator fans. The way I drive, I get less than 10mpg most of the time though. I'd imagine after I go with the turbo setup and build up the motor it'll get around 12mpg highway (NA it'll be built up to around 450hp or so), but that's a fair price to pay. I'm leaning towards EDIS right now with a 4 coil coilpack. I really would rather not bother with trying to do anything fancy right now, I just want something that works. If I can future proof like you said, then heck yes I will. I was thinking though about getting a TA board and just use a breadboard for now while FreeEMS continues to develop. That way I can change stuff and finalize once full sequential is available. Or I could go with a Jaguar board like you said. Either way. I dunno lol
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Fred
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Re: New here introduction, question, and also details.

Post by Fred »

malcom2073 wrote:As far as I know, Jaguar is considered the most up to date, and is certainly the most tested design out there at the moment. You are probably best off basing your design off of that.
Exactly! :-)
You will also be limited to batch fire fuel injection with wasted spark ignition, as there are only 6 timer channels available for use (injection and ignition), as the code does not support full sequential on more than 4 cylinders.
Close. Except the 4 cylinder limitation. 6 cylinder full sequential is doable, just without ignition. Sam, see this: viewtopic.php?f=54&t=1084
Sequential will get you better transient throttle response and more controllable fuel at idle, so not really needed on a drag race engine, but it's not complicated to support in hardware.
These things are not absolute truths. Throttle response is fine for multi shot. Controllable low pw fueling is possible with single shot per cycle, but you get an uneven idle that way. Both at the sane time is difficult or impossible, though.
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Re: New here introduction, question, and also details.

Post by Sam »

So, I guess the plan is EDIS or some form of wasted spark, four coils, and semi sequential? In that case I can go ahead and start ordering stuff. I may just make it on a project board, but if I can print a Jaguar board that'd be cool too. Thing is, I like being able to change things later so maybe a perfboard or a breadboard (not sure how that'd stand up to vibration over time) would be better for me. Any clue if there are any limitations to the max amount of boost with this setup? Also, is there support for nitrous (I.e adding more fuel when a dry shot is added). I have a MAP sensor in my throttle body, by the way. Obviously I can change that if I need to though.
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Re: New here introduction, question, and also details.

Post by Fred »

See this re DIY setups: viewtopic.php?f=62&t=2327

It's not for the faint of heart.

As for EDIS, there is currently no support, but it shouldn't be hard to add. If you choose to go that route, expect to wait.

I would:
  • Setup 4 wasted spark coils (may as well be EDIS ones for compatibility)
  • Drive those coils with dumb ignitors direct from FreeEMS
  • Run 4 shots per channel per cycle alternating timing batch injection on 2 channels (this will be decent NA, and reasonable at 200hp/litre which is still pretty low specific output)
If I get EDIS functional you could:
  • Move the coils to EDIS and run semi-sequential fueling on four channels across pairs of cylinders.
But in all cases:
  • Just buy a Jaguar kit from Andy because:
  • Having your own board printed is pointless and fraught with potential for problems
  • Assembling a BOM kit together yourself is a royal PITA
  • You would be supporting Andy, which is good for everyone
  • His pricing is very reasonable for what you get (M$ systems are lean on core hw features)
Fred.
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Re: New here introduction, question, and also details.

Post by Sam »

https://www.youtube.com/watch?v=qTMExDYujK0&feature

Take a look at this. This, while not solving individual control of cylinders, would essentially create a dummy sequential system. I really like what this guy has done. What do you think of this?

As for EDIS, if I can avoid using it FOR NOW and do like you said, I'll be good. The coils I would use would be these suckers:
http://www.amazon.com/MSD-Ignition-8241 ... B000630380

^Which would be good for EDIS as well. While I would love to have a PCB, I think for me a custom perfboard setup is good for now until I finalize things.
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Re: New here introduction, question, and also details.

Post by Sam »

http://forum.arduino.cc/index.php?topic=207798.0

Here's the thread from the guy who did it. It takes a batch signal, which would be for all injectors, and splits it up into a sequential pattern. Would not be hard at all to do, and definitely would provide some of the benefits of REAL sequential injection. The arduino doesn't have to do too much to achieve this so it's an appropriate method to do so. Also, I'm sorry, I was having a misunderstanding with this. I didn't know that there are only six outputs total, fuel and ignition combined. Just now realized that. I thought there were six of each lol. So now I know what I'm working with.
Sam
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Re: New here introduction, question, and also details.

Post by Sam »

So from what you told me, I could do the following:

Wasted spark, with four coils.
Batch injection tuning for 2 channels, where the signal from FreeEMS will go to the arduino to split up those batch signals into full sequential (so full sequential injection but control is only adjustable for two banks of four cylinders), then the signal from the arduino triggers the actual injector drivers. Sound doable?

This would definitely give me a nice idle and more than sufficient tuning (for now at least).
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