MShift and Toyota A34 Series Info?

[mikeymkll7mgte]

Ok great. I didnt know if it would go crazy if I went above 255 or just follow the last row for the 255. I will just leave it because for those boost levels, Im usually full throttle anyways.

[Bernard Fife]

mikey,

Yes, when the code determines the target gear, the first thing is does is see if the indices are 'out-of-range' (above 255 kPa for load in the default shift table). If the index is out of range, the highest kPa value from the table is used. This is just like the VE table behavior in the engine controller. It's done that way precisely so it won't go crazy!

Lance.

[mikeymkll7mgte]

Awesome! I cant wait to drive it tonight. I will get it out and update everyone on how it does.

[mikeymkll7mgte]

Dropped R45 back to 300K and R59 to 220k and no diode inline. Very very smooth speed signal. Car drove great!! Drove it for hours last night with no problems!

I must have had some serious noise issues with the wire in the harness. I pulled apart a stock harness (97 SC300) and the vss wires are twisted and ran along with other low voltage signal wires on the opposite side of the harness from any injector or coil or 12v wires. When I re-did the harness the first time, I twisted them but didnt pay attention to how close they were to other wires. Maybe I should have. Lance- this might be something to document in the Mshift build files or something for the people building a harness. Im sure people using a stock harness should be fine though.

So far Im very impressed with how this is working out. Im going to keep tuning the shifts and then get it out to the track and see how she does.

[Bernard Fife]

Great, I am glad it is working out for you! I will definitely add a note to the docs (I am also working on a VSS troubleshooting guide), that should be on the site soon.

[Jim Blackwood]

I'm glad you guys got this sorted out, including the boost which I will be using. I never did trust the OEM shielding on the VR pickups. Pretty flimsy to start with, and the aluminum treated foil tends to oxidize and insulate itself from the ground lead if any air at all (O2) can get to it, and then of course they tape wrap it, so if you bend it at all it creates air gaps. Not good. It was probably creating noise when the engine rocked.

There is twin lead shielded twisted pair available in a suitable gage size but it is hard to find. A few months back a truck of some sort unrolled a partial spool of it on the road, and after driving over it a couple times I decided to stop and see what it was. A little heavy at about 16 or maybe even 14 gage, but with a very tough and durable plastic outer jacket. I picked up maybe 50 yards of it and will use it where needed. But that just proves the wire is out there. A thinner and much more flexible variety has to be available.

Jim

[mikeymkll7mgte]

Im very surprised that the oem one worked as well as it did. There must be alot of software filtering going on to quiet the signal down some.

As far as a suitable gauge size, wouldnt any size work? Its only carrying a signal so I would think anything should work. I used the 22awg twin core from DIYAutoTune and it seems to be working great. I know Radioshack carries 24awg two conductor shielded wire in a 50 foot roll.

[mikeymkll7mgte]

Instead of starting a new topic, Ill just ask this here. Im using an Autometer electric speedometer in my car. Part #3988. This is what it says for the calibration-

Auto Meter electronic speedometers are pre-calibrated. When converting from a cable driven speedometer, no further calibration is needed if:
1. The transmission’s speedometer cable take off is 1000 RPM at 60 MPH (97 km). Most vehicles meet this requirement.
If the vehicle’s tire size and/or differential ratio has changed, the speedometer needs to be recalibrated.
2. The vehicle is equipped with a 16-pulse/revolution sender.

I have also found that they seem to be calibrated to 16000 pulses per mile.

When I enter anything more than 12000 PPM into Mshift, the speedometer does not work at all. If I put in 12000, it reads but is reading about 2/3 of what it should. Is this a hardware or software issue? Do I need to calibrate my speedometer to say 10000 or 12000 PPM?

[Bernard Fife]

mikey,

The speedo output works by 'dividing down' the VSS input. So it needs the VSS to be quite a bit higher frequency than the required speedo output. There is more here: http://www.msgpio.com/manuals/mshift/V22tune.html#gv under 'Output pulse/mile'.

If, for example, you had a 4L60E with 40 teeth on the output shaft for the VSS you would get about 96000 pulses per mile from the VSS, and if you needed 2002 or 4004 pulse per mile (typical for a stock GM speedo), then the dividing down works fine.

But if, for example, you had 4 teeth of the output shaft for the VSS, you would get only about 10000 pulses per mile, and this really limits what sort of frequency you can get from the speedo output. This may be the problem you are running into. In that case you might be better off using the VSS for both the MShift controller and the aftermarket speedo.

Alternatively, you can set the aftermarket speedo to accept a pulse/mile value of around 1/5 the VSS pulse per mile (so 2000 in the example above) and it should work fine (assuming that 2000 is in-range for that speedo).

Lance.

[mikeymkll7mgte]

Ok great. I will set Mshift to 2000 and calibrate the speedo from there. I think the speedo said it will do anywhere from 500 to 400,000 pulses per mile.