Push Rod

We've been using a GTech Pro Comp for quick and dirty dyno readings. It works pretty good, but its not perfect. During some surfing, I stumbled across this unit:<br><br>http://www.auterraweb.com/<br><br>Was just curious if anyone has used them, and how well they work?<br><br>Rod

Stamey

I don't actually know anything about it, but I can't figure out how they are using a Palm or any other hand-held for this application. I see no mention of the necessary inertia measurment device the G-Tech has or this unit I am thinking of getting:<br><br>http://www.tazzo.com/tazzo/tazmnt.HTM<br><br>Maybe I missed something. I can see the usage for reading codes from the computer though.<br><br><br>Chris

AlpineRAM

The Auterra is a kind of cool- a scantool that reads OBD and MIL and one of these sensors is vehicle speed. Another is a small odometer. <br>Combined with an internal timer in the Palm it can give you acceleration and 0-60, 1/4 mile etc times. <br>I don't know about the precision of the tool, but with wheelspin it can not be overly accurate. <br>AlpineRAM

Push Rod

[quote author=Stamey link=board=8;threadid=17522;start=0#164710 date=1059361687]<br>I don't actually know anything about it, but I can't figure out how they are using a Palm or any other hand-held for this application.[/quote]<br><br>As Markus mentioned, they're using the VSS, and Palm timer to display an acceleration curve. From the acceleration curve, the unit takes into account vehicle weight, and something that neither GTech or Tazzo does, the co-efficient of drag of the truck. You can also enter in correction factors such as temperature, humidity, and elevation, should you want to use correction factors.<br><br>As long as the VSS is functioning properly, I think the unit could be more accurate than a Gtech or Tazzo, as long as they're using accurate formula for the drag co-efficients (which are complex) and weight.<br><br>Rod

AlpineRAM

Well I think that the precision of the drag formula used does not matter too much if you use it to compare single steps of tuning on the same vehicle. ( Got to be very careful of tire size- going from stock to 255/85R16 might cost you a virtual 100hp) <br><br>Rod- I've been driving around with an OBD2 on my truck and have found out some fun stuff. If you use the BHAF cleaning your A/C cooler can give you 10C less on the IAT sensor @120km/hr. (Flat ground)<br><br>AlpineRAM

Push Rod

[quote author=AlpineRAM link=board=8;threadid=17522;start=0#164766 date=1059377864]<br>1) Well I think that the precision of the drag formula used does not matter too much if you use it to compare single steps of tuning on the same vehicle.<br>[/quote]<br><br>At first glance this is true, but drag increases as speed goes up. So at 10 mph, you may only be stealing 1 HP, but at 100 mph you could be stealing 100 HP. So that mod that adds 100 HP on the dyno will not be adding the full 100 HP when the truck is moving down the road. I don't believe the aerodynamics of our trucks is quite as bad as my example, but when I was asking the engineers at Gtech about it, they found it interesting enough that they planned to add it to a future version, simply to try and echo a typical dyno run.<br><br>One thing I'd really like to know is where the IAT/AP sensor stuff is stored on the 03s. I don't understand how 1 sensor, which is in effect a &quot;dumb&quot; sensor, can be calibrated so that 2 different sensor readings can be obtained. If its stored in an OBD2 reading somewhere, this unit could pay for itself with simple air unit readings.

AlpineRAM

I don't know about the 03s, but there are sensors available from Bosch that do incorporate MAP and IAT in one case. <br>About the drag- I meant that using the device on a truck that is left the same except an engine mod per step should point in the right direction hp-wise. I don't think you'd get absolute readings that are precise (except for sheer luck)<br><br>AlpineRAM

Stamey

Rod,<br>I don't remember where I heard it now, but I heard that drag is a neglible factor until you reach 100 mph. Do you really think the drag's gonna matter that much?<br><br>Chris

Push Rod

[quote author=AlpineRAM link=board=8;threadid=17522;start=0#164967 date=1059425860]<br>1) I don't know about the 03s, but there are sensors available from Bosch that do incorporate MAP and IAT in one case.<br> <br>2) About the drag- I meant that using the device on a truck that is left the same except an engine mod per step should point in the right direction hp-wise. I don't think you'd get absolute readings that are precise (except for sheer luck)<br>[/quote]<br><br>1) Yup, the 03 uses that critter. I'm just wondering how the computer differentiates between the MAP signal and IAT signal, as its only a 3 wire sensor (ground, reference, signal).<br><br>2) Yep, it should. The Gtech has proven itself to be pretty accurate around here. I've used the drag formulas obtained from Gtech and ended up with numbers that you would expect to see from a loading dyno.<br><br>Stamey<br><br>You're right, drag isn't a big deal, but in a quarter mile type of run that you have to use to get these units to read, it can account for 10 ponies without any trouble at all.<br><br>Rod

AlpineRAM

[quote author=Push Rod link=board=8;threadid=17522;start=0#165118 date=1059448776]<br><br><br>1) Yup, the 03 uses that critter. I'm just wondering how the computer differentiates between the MAP signal and IAT signal, as its only a 3 wire sensor (ground, reference, signal).<br><br>Rod<br>[/quote]<br>I think it uses sig1, sig2 and common ground. (At least per catalogue for the ones I could get)- Calibration on ground resistance is done by comparing coolant temp with the resistance of the temp sensor to obtain a basic reading and map at engine standstill. <br><br>AlpineRAM

Push Rod

[quote author=AlpineRAM link=board=8;threadid=17522;start=0#msg165162 date=1059467885]
I think it uses sig1, sig2 and common ground. (At least per catalogue for the ones I could get)- [/quote]

Well that makes more sense. I should have probed the sensor instead of assuming. Now, I wonder where that AP reading gets stored in the computer? Mass Air Flow is part of the OBD2 specification, but I don't see air pressure in there anywhere.

Rod

AlpineRAM

AFAIK and as far as OBD2 is the same as EOBD mass air flow is only needed to be protocolled for gassers. Since MAP and IAT combined will give correct MAF values for the stock exhaust ( or with a programming excemption for when an exhaust brake is applied) and the exhaust gas will not get more poisonous if you lean the engine (opposed to the gasser with cat) there is no need for MAF protocol for the diesel.
On the 2nd gen I saw the MAP displayed on a proprietary sensor information. Only malfunctions like overboost or overfuel for a certain boost (if the PCM knows about- not for devices that connect to the pump wire- therefore only if the FPCM reports a high value for fuel delivery to the PCM while there is low boost)have to be reported.

AlpineRAM

P.S. Rod, driving with the laptop on is dangerous ;D Don't ask me how I know :-[

FiverBob

Alpine,
I drive with the laptop on quite a bit. It talks sweet things to me - - like &quot;hey jerk, you were supposed to turn left at the last corner - - now I suppose you want me to figure how to get you out of this mess, right? Yeh, sure - - you big dummy!&quot;

Lucky for me my wife gets to answer it or it would probably direct me to the nearest boat ramp and tell me to accellerate. ;D ;D

WhatLastCorner?Bob

AlpineRAM

Bob: I have seen guys with nav systems turn right precisely at the moment when the system said so. But I have seen the scared face of some passengers when starting to answer tech support e-mails at 100mph on hte highway. Didn't seem to be good for their digestion ;D

Actually one of the coolest features to me is to record all the relevant values from the PCM, ECM and a SensorPack while driving.

AlpineRAM

FiverBob

[quote author=AlpineRAM link=board=8;threadid=17522;start=0#msg167065 date=1059764766]
Bob:
Actually one of the coolest features to me is to record all the relevant values from the PCM, ECM and a SensorPack while driving.

AlpineRAM
[/quote]

From the WHAT? Is that right next to the distributor? Oh, how about the spark plugs - - are they OK? ??? ;D ;D

I have not been brave enough to fuss with that stuff - - - YET. :P Maybe someday. My diesels have been too big for me to mess with. I will probably fool around with this one sometime, but not yet. I like them thar factory warranties real well. My dealer has been super with me and I will not rock the boat. I sure enjoy hearing you guys talk about it - - I have learned a lot.

DumDumBob