My life, My coding

[Rx7man]

it's not sounding right... it should be
black/light blue (gnd), orange/dark blue(signal), Violet/white (+5V), and this seems to hold true for all dodges of the era.. gas or diesels...

I can guess the black/white you see is actually black/light blue... a straight orange is an +8V supply, for the hall effect sensor on the front of the engine and vehicle speed sensor on the tranny.  I'm not seeing anything in the diagrams of a red wire that is in a 3 pin plug.

[hakcenter]

Pretty sure it is it!

Google image


I have a Black, Red/Black and, Violet/White. Verified 5v on the Violet so I'm guess it is the plug, looks just like it in the picture with the a/b/c

[Rx7man]

Red/black is really hard to tell apart from Orange/Dark blue on old wiring.. If it looks like that plug, it probably is....

You will need the bracket to hold it from an auto tranny truck as well, and there might be some other little tab or something needed to actuate it.. the tab you see on the linkage isn't big enough to do any good, I had to weld a piece onto mine to make it work

[hakcenter]

Ok cool then it's time to eBay

[Rx7man]

or perhaps find a wrecker?  craigslist parts truck?

[Rx7man]

Well, I've been playing with the truck a little more.. I seem to be getting good mileage on this tank... and it's a lot of city driving too.  I open the vanes quite wide when I'm on the highway... running 2600 RPM, 75MPH, I'm only at about 5 PSI, truck sounds like it's happy as heck, virtually no backpressure... truck is all sideways in 4th on wet roads at 50 mph.. I still have some tweaks to do in the mapping, but I'm getting some good results so far.

One problem I'm having is my exhaust pressure is VERY uneven.. bounces all over the place despite anything I try to do to smooth it... I'll look into that a little more too.

[Rx7man]

I also bought (because I just stumbled on it) some REALLY fine soldering wire.. 0.3mm or .015", as well as flux for it too

[me78569]

Slow your vane adjustment down.  I am now never moving my vanes more than 5.  I found that if the vanes jumped more than that backpressure was VERY unstable. 

I am thinking of reducing it even more. 

[Rx7man]

and how often are you adjusting the vane position? 20ms?  I might try that..

Truck is running good.. there was a car riding my ass on a highway on-ramp, I tromped on it heavily and smoked them badly.. both literally and figuratively speaking... went from 35mph to 75mph by the time I merged... cruise is working nicely, holding steady at 5 psi, and jumping to 20 as soon as you demand power.. off idle is pretty good too, getting 20 PSI by 1500 RPM in lower gears, 30 is no sweat by about 1800.  Buddy at BD diesel loves it.. I have yet to take him for a rip in it though

[Rx7man]

I changed a little of the logic for vane movement.. it won't move unless it has to move at least 5 points, and is limited to 20 points ever 20ms.. I can definitely feel the slower reaction, I might speed it up a touch, but I want to totally rethink the logic and have the movement based on a curve.. so the further away it is from where it's supposed to be the faster it reacts, which will help prevent unnecessary motion on small changes, but still react quickly to large changes.

I also have a little bit of an issue I have to try and figure out, when it's cold out it seems like the VGT opens up against it's command.. at first I thought it was the voltage drop caused by the grid heaters, but then it happened once long after they quit cycling.. kinda hard to tell what's going on while you're driving, but it came back after 5 seconds or so... I'll have to figure out if it's the controller telling it do do something wrong, of the comms are cutting out, or a voltage supply problem

[hakcenter]

Unplug your USB cable while you're not connected and see if it goes away

[me78569]

I honestly think that any movement over 5 is too much.  For my truck it seems that it will always overshoot the vane position truly needed to control shaft speed, drive pressure drops and shaft speed falls.    I seen a huge reduction in drive pressure jumping as soon as I made that change. 

I am running the send Vane position every 2 ms.

[Rx7man]

I think I got it.. I had a drive pressure ratio limiter, and changed it so it doesn't act at 0% TPS and come to full at about 40% TPS... so far it seems to have fixed it.

I also bought a Garmin GPS for cheap.. I'm wondering if I can somehow hack it and turn it into a touchscreen... It has a good controller in it, GPS, bluetooth (for serial comms??) etc... I would just have to find a way to put my own firmware in it and probably have it talk to the Arduino over I2C or something

[Rx7man]

I am getting a pretty good tune into it otherwise.. I cruise at 75mph with the turbo pretty much wide open, I have it at about 870 at idle which just keeps it spinning without putting a whole lot of backpressure, so that helps city mileage where I do a lot of putzing around... it flashes up pretty quick.. at 2500 RPM it happens *really* fast!

[Rx7man]

Well.. I've put a lot of miles on it now, things are working pretty good.. still doing some fine tuning, after which I will need to make a better monitoring system for the final touches so I can datalog effectively and hopefully display in graphical form.. with any luck I can do it on the GPS unit I got, but if all else fails I can do it on the laptop.

I was towing the trailer home, and I was fighting a 30mph headwind, and my mileage sucked some serious arse (1/4 tank for 80 miles) but apart from that I was getting about 400 miles to a tank without running on fumes in combined city/highway driving while empty.. I think that will improve when I get the 3.55 gears in (I just got my rear diff, front will here soon)... I have to put new brake rotors and U joints in the front axle as well as most of the driveshafts, so I'll do it all at once.

Some features I've been playing with are a TPS rate based vane closing algorithm.. basically when you mash the throttle, or when you're frequently changing throttle position, it closes the vanes, and has a time-based re-opening, which increases boost when you're going through the gears, but backs off for good mileage when you're doing steady cruising.. I have to play with the limits on it a bit, but it's showing promise so far... I may have to change it from an absolute position to a percentage since 100 VGT points when you're close to closed is much more serious than from near wide-open.. I may have to do this on several 'compensating' variables.

When I get to the point I feel like most anyone could plug-and-play what I've made, I'll post a full copy of the sketch