nAst1: Progress and Concepts Thread

[robertisaar]

more or less.... especially with the SFI PCMs, as far as i can tell, even the OBD2 6811 applications used a carryover IC from the early P4 days, a 52-pin piece entirely dedicated to injector sequencing/control, accessed via SPI.

[brian89gp]

though now that i think about it........ if someone were to somehow adapt the HFV6(or any, really) cam phasers to the LQ1..... i would be quite amused with that as well. you could even account for chain and belt stretch to keep cam timing consistent.... or track belt stretch and set off an alarm when it exceeds whatever safety threshold you determine?

Or perhaps more importantly, control a HFV6 including the cam phasers with an OBD1 PCM. I don't see many going through the trouble of adding cam phasers to the LQ1.

[robertisaar]

could be done, even with relative ease, with a few retrofits... trying to read the HFV6 crank reluctor would be challenging. i know the P4 can be(as in, already is) setup to trigger an interrupt on the falling edge of the crank reference, but i don't know if rising and falling is allowed, as was done with some P6 units(LT1) for cylinder decoding. even then, that can eat up a lot of processing time considering how many notches there are on the newer reluctors.

i would seriously recommend the 6+1 reluctor/DIS setup for the sake of simplicity/capability. otherwise, to use it without seriously hampering processing time, one would have to....... add another IC to offload work onto. perhaps dedicated only to reading the crank reluctor and could generate the 3X pulses the PCM wants to see? but then nothing would be controlling the coils themselves unless the new IC did it as well, since the single EST line from the PCM wouldn't be able to handle all 6 coils, even if they were paired up to fire in waste-spark mode.

so..... essentially, that would require a new ICM as well. which really doesn't sound all that out there compared to controlling 4 cam phasers. the new ICM would still rely upon the PCM's single EST signal to know when to fire a coil and would generate the 3X signal the PCM wants to see, but now it needs to be relatively intelligent and fire the coils one at a time(and have either some kind of cam signal to know which cylinder of the pair is which or fire the coils off in waste-spark to start and then while running, turn off a cylinder, see if a drop in engine speed happens, if so, turned off the wrong cylinder of the pair, if not, correct cylinder was turned off) and start dwell sequencing and ....... and ......



do i ramble this much IRL?

[brian89gp]

For the crank trigger, it is pressed on so it is replaceable just like the 3500/3900 is.

....Or go this route. Customizable input, GM DIS output. Plus have the option to use the COP this way.

http://pcmhacking.net/forums/viewtopic.php?f=11&t=2913

Don't get me wrong, I love the LQ1 (just ask Ben or Jon here) but if the 3.6 DOHC is a viable alternative I would be hard pressed to still chose the LQ1. In design I am pragmatic first.

do i ramble this much IRL?

I dunno, do you? Isn't that the reason for these specialized forums so that we all can ramble on about what we are passionate about that IRL you would be hard pressed to find someone to even care?

[robertisaar]

i remember that thread..... looks like it still hasn't launched in an official way yet, though?

it would seem i would be reinventing the wheel, but at the same time...... it's nice to know exactly what is happening and how it is doing it, especially if you tinker with it endlessly, which seems to happen a lot with me.

a variable cam phasing LQ1 would be interesting to see, but i don't see any/many doing it either, more of a thought of capability, rather than practicality, kind of like sticking a LQ1 in a 2nd/3rd gen W-body, it could be done, but is only ever proposed by one-post-wonders.

in reference to rambling: i...... occasionally get the feeling that i not only jump off the deep end, i stay under a bit too long.

[ericjon262]

in reference to rambling: i...... occasionally get the feeling that i not only jump off the deep end, i stay under a bit too long.

lol...

[brian89gp]

I imagine something will come from that product eventually and if not a standard GM DIS wheel could be put on the 3.6 DOHC crank without too much difficulty.

in reference to rambling: i...... occasionally get the feeling that i not only jump off the deep end, i stay under a bit too long.

Takes all kinds to make the world go round.

[ericjon262]

flexfuel maybe?

I found an inline fuel composition sensor.

http://store.haltech.com/usastore/accessories/ecu-inputs/flex-fuel-composition-sensor-suit-3-8-hose-inc-plug-and-pins-usa.html

probably way overpriced...

[robertisaar]

it might be. i imagine factory ethanol/methanol content sensors would be useful as well, if you could find them. rockauto doesn't seem to carry the one used on the methanol luminas of the early 90s, or at least not that i can find.

[unchained01]

http://paceperformance.com/i-1080149...ensor-e85.html This is pretty cheap compared to the others, still need a gauge

[robertisaar]

interesting, that is certainly cheaper. variable frequency.... is interesting to write code around compared to a 0-5V linear output, but a freq->voltage conversion IC could take care of that.

[unchained01]

yes that and a gauge for under $275 compared to almost $450 for the other

[robertisaar]

i'm not sure why a guage would be needed? unless you wanted to be able to check fuel composition without using the datastream, in which case it makes sense.

if i wanted to monitor composition with reasonable accuracy, i would run the variable frequency signal through a converter, then setup a LED bar meter that changes in relation to voltage. i know there are at least 10-dot resolution versions out there, which isn't horrible, i guess.

[unchained01]

I can see for obd-I and your knowledge that would be great I am running OBD-II

[ericjon262]

I bet both of those sensors are identical internally, the haltech unit just having a fancy case...