nAst1: Progress and Concepts Thread

[pocket-rocket]

That's a heck of a price break at the 5 piece mark on the 727 style for connectors. It drops from $10 to $5.25 I'm going to stick with my 396 for ease of installation/cost/availability lol

[robertisaar]

eventually, the 9396(or an extended RAM modded 7730) is going to be the only PCM capable of running the later revisions anyway... it still uses the 7727 plugs/pins though.

[mswenson289]

9396

eventually, the 9396(or an extended RAM modded 7730) is going to be the only PCM capable of running the later revisions anyway... it still uses the 7727 plugs/pins though.

Does the 9396 use the 7727 weathered connectors or is there a 7730 intieror version available.

[robertisaar]

externally, a 7727 and 9396 are identical in appearance and connectors, the only way you can determine which it actually is would require removing the MEMCAL cover and looking inside for the extended RAM chip (which bumps RAM up from 512 bytes to (i believe) 1024). or look on the sticker, but that's a little less reliable, assuming it's still there.

as far as i know, there was never an equivalent PCM made that uses the 7730 style connectors and uses the P4 processor with the extended RAM chip, though you could find a PCM with the extended RAM chip, remove it, and solder it into a 7730 and basically have a 9396 in a 7730 case. otherwise, the 94-95 3100 MAF PCM MIGHT work(it's also an extended P4 MCU and is an interior-mounted version of the 94-95 LQ1 PCM), though i cannot guarantee it, and the pinouts will be far different.

easier said than done though, it's a surface mount PLCC chip. i may need to pop open the wife's 7727 and my 9396 to show the difference...

[Superdave]

the 94/95 MAF 3100 PCM does not like my test bench.. i found that out pretty quick.

[robertisaar]

the 94/95 MAF 3100 PCM does not like my test bench.. i found that out pretty quick.

were you emulating synchronized 24X and 1X cam signals i addition to the 3X signal?

that's the biggest difficulty i've ran into so far when trying to plan my own bench...

seems i need to go PIC based to accomplish that.

[robertisaar]

slight stall in the project: GP needs a steering rack, making it more or less undrivable until i get around to replacing it.

however, a question comes up for anything thinking of running a MAF: does the range of 2000-10,192Hz pose any kind of problem? that's how it's setup in $2E, however, i can easily extended the tables in either direction, so long as i do it in 1024Hz increments. i was thinking a range of 976-11,216Hz would be great, since it actually would provide even more range than any OBD2 setup i've seen, without sacrificing any of the resolution. the MAF tables themselves are setup in increments of 128Hz, which is JUST barely less resolution than the common 60 and 90 V6 OBD2 OSIDs, which goes in steps of 125Hz.

also, should you be wanting to run a MAF, get yourself a MAP sensor as well(assuming you don't have one already), 1 BAR if you're not planning on boost, and a 1 AND 3 BAR if you want boost(applies to speed-density only guys as well)... reason being, i'm going to set the code so that when any quick throttle change events detected, the MAP sensor will be used for fueling calcs(in S-D mode), since it responds faster to airflow changes than a MAF will. sounds familiar? most OBD2 programs do the same thing for enhanced drivability. i WILL have an adjustable value to change the amount of throttle needed to disable the MAF, though i'll likely have the value set rather low in the "stock" tunes. if you raise it to the maximum value possible, it will essentially disable speed-density fueling, should that be desired(not recommended, since all AE/DE calcs are based on speed-density).

the reason for multiple MAP sensors? well, the 1BAR will be used for any existing calcs, then should MAP rise above barometric pressure, a BPW multiplier based on the 3BAR MAP will be used(since i don't want to waste the space on the PROM for different algorithms due to sensor differences), i'm not sure if i'm looking at 5 or 10kPa resolution intervals yet, since the fueling trends shouldn't be THAT dramatic with rising boost...



i believe Penglii has been having some decent luck with the single-fire/enhanced VE 8F BIN i made, so that's promising news at least. rack should be dealt with by the end of the week and code tested then, so watch for updates in the next couple of days.

current order of stuff to impliment looks like this:
single-fire stuff
2-step rev limiter
MAF ability
3BAR stuff

i think i can get away with most, if not all, of that without using any more RAM as well, so that's a plus. keep in mind, i don't have a MAF nor a 3BAR MAP sensor, so i may need someone to bench-test or real-world test the additions when they come into play. possibly two-step as well, since i don't see myself running it on the GP anytime soon, if ever.

[pocket-rocket]

I was thinking how nice it would be to get the 92 in the garage in the next few weeks to clean it up a bit, even if it does need need new rims/tires to drive. I could also fix my clutch bushing issue and test the two step as long as I could copy the tables over in the chip that's in it now even if it is a 1.5k and 2k rev limit just to test.

[robertisaar]

well, i need to get the single fire tested, then i need to decide which pins to use for the 2step... whatever pin the clutch switch is hooked up on a 9396 will be the "activator", so for a manual trans, the clutch switch, for an auto it's the brake, then the "bypass" switch (would any manual trans cars need this as well?), to bypass the 2 step code and use the regular rev limit in case you need a higher RPM with the clutch/brake engaged.

[pocket-rocket]

I can't think of anything off the top of my head (other than a big smokey burnout). You could put it in there so that it's there and doesn't need added later, and if the user so desires it to be hooked up, they could pin/run the wire and have it be there. That's how I would do it if it were me doing it.

[robertisaar]

^ that is the most intelligent method of going about adding in the functionality...

i know the RWD vehicles are going to benefit from it, but FWD, less so.

[Superdave]

Since you are now a $A1 master... the 2nd gear switch and 3rd gear switch inputs to the ECM, are those just used for the TCC low/High gear settings or is there more to it?

my 700R4 has a 4th gear switch but no others, i hooked that up to the 3rd gear input for now since i figured it was just for a TCC enable constant.


Thanks

[robertisaar]

good question!

all instances:

at D698, it's tested against to determine if TCC lockup should be enabled, first the 3rd gear switch(which should be enabled in 4th as well, at least on a 4T60), then minimum coolant temp to allow lockup is checked, then maximum coolant temp to allow, then 4th gear switch is checked, then it starts checking for D-TPS qualifications to lock/unlock.

at D918, it's checked against to see which "apply" tables to use, mid-gear or high gear.

mentioned at D7C2, is for F31 trans only.

D84C: also for F31 trans only.

D82D: also F31.

AA03: used for "spark retard during shift" stuff, checks for 2nd and 3rd gears, possibly F31 only.

AD44: checked to see what values to use for torque management, 2nd, 3rd, and 4th checked.

A3B0: checked against to see if A/C should be disabled due to downshift.



that should be all of them... 2nd gear switch seems to RARELY get checked compared to 3/4...

[Superdave]

which input is for the 4th gear switch? It's not on my Jbody pinout.. I figured they left it out since Auto $A1 was only used on the TH125.

[robertisaar]

for the J's yes, only on the TH125... 3.1 W's were $A1 from 91-92 and had the 4T60.

on a 91 3.1 W, i see it on D22, which corresponds to D14 on a 7730.