NICE!!! i can't wait to hear about this.

 

Well, air temp testing proved to be inconclusive. I think it's because the IAT sensor is slow to react. The way I did the runs was to start the capture just before I put the pedal down at the bottom of the hill. I started at 50 mph in 5th. When I let off the accelerator at 70 I marked the capture, the capture ends automatically 14 seconds after the mark point. I got the same result both times - 46.4 degrees F. This is the same temp the sensor was showing real time at idle while checking the captured data. I know the sensor works because it was showing 98 degrees when I started the truck (plugged in overnight), and while driving around to warm up the engine for the tests I saw temps as low as 39 degrees in real time monitoring. Outside air temp was 30 degrees. I think the IAT is too slow for an acceleration test. Perhaps a better test would be to haul a trailer for a mile at 25 psi so temps can stabilize. Unfortunately I have neither the trailer nor the terrain available.

 

hey dave, by IAT do mean one of those $265 or so autometers? i've been eyeballin those things for a bit. trying to figure a "cost effective" alternative

 

The IAT is the sensor that is in the manifold to monitor air temp so the PCM knows when to run the grid heaters. The scan tool I'm using is one of those el cheapo Auto-XRay scanners. It's an old non-OBDII scanner that I picked up cheap. Once I get a tach I'll use the scanner to calibrate it, that's really the only reason I got the thing. There's not much the thing can tell you on a 1st gen with a 5 speed. Air temp, coolant temp, voltage, road speed, RPM, and battery temp are the outputs on mine.

 

WOW, why did`nt I think of that!!! I have been wondering how I was going to caibrate my Autometer tach, GREAT IDEA!! I have access to a Snap On scan tool that`ll plug into just about anything with a diagnostic plug, I`m gonna have to ck it out, THANKS!!!

 

Dave, I'm jealous! I wish I could play too. Must be nice to have your boss

 

Man i really want one of these systems. It's been a couple of days now...............you ready to get rid of it yet?
-Jim-
P.S.- Keep us updated on the new feel and stuff, i am going crazy reading this string over and over and over.8)

 

I only had it kick in a couple times on the way home today - dang traffic. I couldn't play on the way to work because the roads were snowy. 2wd dually w/ @750 ft# of torque + snow = dually in a ditch if you aren't careful.

I've got the system tuned pretty well now, it kicks in at 20 psi and gives full flow around 30 psi. I had to back off the pressure setting a little today, on the way home I was coming up a steep hill at 45 mph in 4th at part throttle and the truck burped a little when the boost hit 20 psi, I guess the flow was too much at less than full fuel. I backed off 1/2 turn on the pressure screw, I'll come home the same way tomorrow and try it. I want this system to be transparent, not like a nitrous kit , that's why I spent the $$$ to get the Snow system with the progressive controller instead of rigging a low buck system with a Hobbs switch.

I still want to try air temp testing, I'm going to try to find a hill that I can hold 25 psi on for 30 seconds or so. I can think of a couple that might work...

 

DANG SNOW! STUPID SNOW! BAD ICE! STUPID ICE!.......When does it thaw up there, its warm here. Come down here to florida. No hills to test on though. I am waiting to hear more when you get to it.
-Jim-

 

You know, you might not be seeing the change in IAT snsr data because the either A, the baud rate for that stoneage PCM Dodge put in there is just too slow or B, The scan tool "sample" rate might be too slow. If you have access to a service manual it might have a temp/voltage matrix and you could backprobe the connector on the sensor with a multimeter wich should show changes in voltage almost instantly...just an idea

 

That seems like work though...

The scanner does give voltages, I guess I could plot out a rough curve and try it that way.

The reason I think the sensor is too slow it that the capture mode gives me one data point per second, up to 28 seconds of info. The temp went from a minimum of 41 while cruising at 50 mph before I romped on it, to a max of 46 at the end of the test - after the acceleration event was over. There were no spikes at any point, the actual acceleration event was around 10 seconds long. The temp was at 46 degrees idling when I checked real-time info after looking at the captured data.

I think the sensor may be purposefully slow because of its function. It's a glorified "on" switch for the grid heaters, a fast sensor might have played havoc with the post-start heating cycle.

 

Hey Dave, are you using the 375ml or 625ml nozzels?

 

625's. I don't think I would have been able to bog the motor on the 375's. If you can't bog the motor, you don't have enough flow. I turned the pump up a lot from stock, I lost track of where it is. I know I'm at least 6 turns in from where the pump was set when I got it. I backed it off another half turn today due to the part throttle/high boost stumble, we'll see where that gets me. If I can't cure it by dropping the pressure, I'll raise the cut in point a little and go back up on the pump pressure.

Gonna put water/meth on the Benz?

 

Six turns on the full fuel screw wannadiesel? Holy Crap...........i didn't know it would go that far, lol. Hows the mileage with 6 turns in?

 

No, silly - six turns on the water/meth pump screw. It has a pressure switch that's adjusted with an allen wrench, they say it's set at 140 psi from the factory.

Mileage? About a quart a minute - so that's like 5 mpg if I'm doing 90.