nAst1: Progress and Concepts Thread

[robertisaar]

Actually would it be easy enough to add the boost-enabled output to 1.08? Just something that provides switched power or ground.

For meth control. Wouldn't be as ideal as a controller but works as a simple control scheme. It would control a relay that turns on the meth pump basically. You could still change the amount of meth injected by changing nozzle size.

okay, now i see what you were saying.... for some reason, i was thinking 2 digi outputs instead of 1 digi in 1.08 and add in the PWM when possible.

[caffeine]

what's the purpose behind that? i don't think you would be able to directly control a wastegate solenoid with that kind of scheme...

For meth control. Wouldn't be as ideal as a controller but works as a simple control scheme. It would control a relay that turns on the meth pump basically. You could still change the amount of meth injected by changing nozzle size.

[robertisaar]

what's the purpose behind that? i don't think you would be able to directly control a wastegate solenoid with that kind of scheme...

[caffeine]

Ya pretty much.

[robertisaar]

Actually would it be easy enough to add the boost-enabled output to 1.08? Just something that provides switched power or ground.

so, just digital output? "when boost above xx kPa, ground, when under xx kPa, remove ground"?

[robertisaar]

boost solenoid/wastegate control could be done on the pin normally used for EGR3, much like how it was on TGPs. that's a PWM output.

as far as computerized meth control.... not sure. if it needs to be PWM, then possibly the AIR divert/shift solenoid A pin(though that wouldn't be possible with a 4T60E(unless you were running a seperate trans controller)) or the CCP pin(wouldn't be allowed on later 4T60E unless seperate trans controller).

if PWM isn't a requirement.... possibly the EGR 2 output.



perhaps another project would be to just remove all trans controls(except the TCC/shift light output) and force anybody running anything more complex than a 700R4 or 4T60 to use a seperate box(either aftermarket or the 7730TCM project), but i'd like for the 7730TCM to be 100% first. that would open up 3 outputs, two of which are PWM, along with a few digi inputs and 1 analog input.

[caffeine]

Actually would it be easy enough to add the boost-enabled output to 1.08? Just something that provides switched power or ground.

[caffeine]

Programmable boost-enabled output which could be used for meth.

Boost control solenoid control like in code59.

Maybe some other programmable outputs.

[robertisaar]

for 1.09, assuming i don't drag ass on 1.08 and just integrate it then, adding a D-MAP threshold for AE seems like a good idea.

any requests on 1.09?

[robertisaar]

notes for new version:

while doing some investigation for Ben, i discovered something odd: in earlier masks, pretty much every platform had unique mode 0 responses. these would normally be used only on vehicles equipped with trip computers(DIC/DIS) and some digital clusters. A and W body cars shared the same stream and is what all of the other platforms started using by the time A1 came around, except for J cars, which oddly enough retained at least some of it's 6D originated stream.

anyways, i guess this is only really relevant if you have a digital cluster(or a trip computer) in a J, L or F car, since A and W car digi clusters work out of the box. other platforms.... no idea. i've added in a patch for the L-cars to use their 87-90 digital clusters, i'll add the others in as necessary(or should i feel ambitious and get them done ahead of time).

otherwise, working on code for the previously planned 1.08 stuff now.

[robertisaar]

as uninformative and dickish sounding of an answer as it is, "when i feel like it" is still accurate.

just haven't wanted to punch out the ~40 lines of code left to finish up 1.08.

[caffeine]

Interesting, thanks! I'll have to try that out.

Any idea when 1.08 will be finished?

[robertisaar]

i'm not sure if the cavity will be open on your connectors, but the 7727/7730 and derivatives have a pin for VSS output that is run at half the fequency of the 4K/PPM signal, so it's obviously named the 2K/PPM signal circuit....

here is a small section of the diagrams Ludis made of the 7730 boards.



explanation for those that haven't caught on:

VSSHI is the "high" for the magnetic VSS(the "low" goes directly to ground once inside the PCM). VSS# is the optical VSS signal coming from the speedo buffer. VSS is the signal that goes to the IC that the 6811 uses for most of it's timing critical I/O stuff.

anyways, following VSSHI, signal goes through a 51K resistor, filtered by a cap of unknown value(forms a low-pass filter), goes into the U24 IC. there the signal goes into a zero-crossing detector(magnetic VSS causes a large spike in voltage, both positive and negative, so when the signal goes above, then below the 0 volt threshold, an event is registered). from there, the signal branches off and goes into U10 for further signal conditioning for use by the processor. the branch we're interested in stays within U24 and goes down to the divider.

the divider is programmable, there are 3 circuits(DIVA, DIVB, DIVC) that are processor controlled and are chosen in the calibration via KSPDDIV. possible divide values are 1, 6, 7, 8, 9, 10, 11. so the raw magnetic VSS signal can be divided by one of those numbers, then pushed out to U14, then back into U24.

normally, the VSS4000# circuit is used to drive the speedometer(and odometer) and so you setup the KSPDDIV divisor to divide the magnetic sensor's signal as close as possible to 4000. doesn't always work great depending on the number of cuts in the VSS reulctor and tire height. with RWD, you also have to factor in final drive ratio. a lot of the time, you can't get very close to a divisor with anything other than factory or close to factory parts combos. in the case of the T56, the VSS reluctor and final gear multiplication tends to put the maximum divisible value out of range, so the speedo would never really read correctly(though the speed the ECM calculates would be accurate if the correct PPM signal is entered). the F40 with it's ~60,000 pulse/mile setup also runs into the same problem.

well, now an interesting solution would be to simply move the cluster's 4K PPM signal over to use the 2K PPM circuit, making the divisible possibilities 1, 6, 7, 8, 9, 10, 11, 12, 14, 16, 18, 20, 22. i don't THINK /2 would be in effect with /1 on the 2K circuit, but i could be wrong.



in any case, note two VSS 2000 output circuits, one is inverted, one is not. seeing how the normal 4000 PPM signal is also inverted, it's safe to assume that would be the route to go with the 2000PPM signal. so, VSS2000A# is the winner here, on a 7730, it comes out to B12. on a 7727, it comes out to B16.

further signal modification for a magnetic sensor is most easily done after the divisor since it's a variable frequency DC signal, rather than AC. if you can't get it close enough with the divisors, then that is the route to go. otherwise, you would have to buy commercial, like the dakota digital unit, or use a DRAC from a truck. me, being a DIY kind of guy, i have plans of using an ATTINY or ATMEGA(probably running on a version of Arduino) to allow for VERY fine resolution of a final divider/multiplier, just haven't wanted to write out code for anything lately, let alone something i've never worked with.

[caffeine]

I'm using a magnetic speedo and ideally a /2 divisor would get me close with 4.11 gears. What's your idea?

[robertisaar]

caffeine: i had to clear out my inbox the other day, forgot to save our conversation on the speed signal...

were you running a magnetic speed sensor or the speedometer buffered optical unit?

if you're using the magnetic setup and need a /2 operation done to get the signal close, i just found by far the simplest way of going about it.