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Old 11-10-2015, 03:57 PM   #25
02TXT
Not Yet Wild
 
Join Date: Apr 2013
Posts: 30
Default Re: Fuel Injected TXT 295cc w/ LS2 Coils

Quote:
Originally Posted by 1989Marathon View Post
Can you tell me what it is about the fuel delivery portion of the Speeduino project that is "far more advanced"? You don't need to add complexity for the sake of fuel delivery. I have MAP, IAT, TPS, AFR sensors, multiple fuel maps, acceleration enrichment, etc...

I am not running parallel processors. I have 2 independent processors, with the sensors wired in parallel to each of them. This was one of the steps I took to be able to achieve deterministic timing.

As for the missing tooth/hall setup, I can only imagine that the firing of the injector is based off of a specific tooth position, not all of them. That makes the only important tooth, the last one before injection starts.
Why is it specifically that you think a single trigger can't be used? The only reason I can come up with is because of a variation in processing time. The engine speed can't change fast enough within one revolution to have appreciable effect.

I'm not suggesting that we should avoid any additional information as it would burden the processor. The additional information(MAP, TPS, IAT, AFR) should be input to the controller during the main program loop. ~1msec.

I have already achieved deterministic timing with both controllers. It is less a function of the controller, and more a function of the speed/accuracy/repeatability of the Schmitt trigger, and the efficiency of the code I have written.

I'm also not trying to say that automakers are just too lazy or not smart enough to engineer "deterministic timing". I'm just saying that I don't believe it is necessary to have a toothed wheel. That will reduce complexity and cost for the end user.
When I use the word timing, I am speaking of ignition timing, not fuel timing. As I stated, one tooth setup like yours is fine for fuel only. That was how I ran my cart to start with... but if you ever want to start advancing your ignition timing to get more power, you will have to add a missing tooth wheel.

As to why the Speeduino is more advanced than your setup, it is a long list of functionality, but to sum it up simply, it does fuel and ignition timing.

When do you think you will have your cart back up and running?
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