1G Electronic Boost Data Logging

[cbatters]

ELECTRONIC BOOST LOGGING FOR 1st GEN ECU
Just a short FAQ on an easy mod for adding a boost signal for anyone using either the MMCd or Shiver's SW on a 1G ECU. The mod takes advantage of an unused EGRT sensor on all of the Federal ECU's.

Many thanks to Jeff Lucius for putting the bug in my ear on an earlier post about an "unused input."

8/10/04 Thanks to RDMelton for pulling together additional instructions / pics on a web page.

http://rdmelton.autoeducation.com/ca.../boostlog.html


FAQ
EGRT ECU input is just a 0-5 VDC input signal on the ECU. ECU doesn't care whether it is a boost signal, wideband O2, oil pressure or fuel sensor. MMCd and Mirage Datalogger have sensor configurations to correctly scale either the 2.5 or 3.0 BAR MAP sensors.

For those of you running PocketLogger, ask them to get on the ball and provide user scaling options for the EGRT input.

WIRING
Only 3 wires to get boost logging working. +5V, Ground and signal.

Note: EGRT input has 10K ohm resistor to +4.5V to provide excitation for the EGRT sensor. This is why the logger will show raw data of ~229 counts or 90% of full scale before you connect anything to it. (If your connect the EGRT signal to EGRT ground the count will go to zero.) THe 10K pullup resistor does not have any negative effect on the accuracy of the MAP sensor.

MAP - HARNESS 3SI Updated color codes from RDMellon - Thanks!
-----------------------------------------------
+5V - TPS Connector (Green/Yellow)
Ground - EGTR Connector (A22 - Black)
Signal - EGTR Connector (A22 - Light Green/Black)

A-22 Connector is located near the injector resistor module - may be taped up with some other wires.


MAP - HARNESS DSM (DSM info from QuasiMondo - Thanks!)
-----------------------------------------------
+5V - TPS Connector (green/red)
Ground - EGTR Connector (green/black)
Signal - EGTR Connector (blue/yellow )

GM SENSOR INFO (provided by Jeff Lucius)
The GM 3-bar MAP sensor is available from MSD Ignition. Search google for MSD2313 or MSD-2313. The store below sells it for $49.70

http://www.aquamist.co.uk/sl/plist/p...6/806-666.html

You'll also need a socket/harness connector. Conduct Tite (PN 85146) sells some that are a close match or that may need only a little bit of knife work to make the correct notch for the key on the sensor connector. See middle pic and red rectangle in the web page below for where notch needs to be added.

http://www.tognottisautoworld.com/se...UCT_ID=MSD2313
http://www.hondata.com/3barinstall.html

Better GM Map Connector - Thanks to Fakepower
AC delco Part #PT1035 .... here are some pics of the cable.

http://www.3si.org/forum/attachment....chmentid=41842
http://www.3si.org/forum/attachment....chmentid=41843

ALTERNATE SOURCE for GM SENSOR (Provided by TurboBob)
www.gmpartsdirect.com
Sensor part number 12223861
Connector # 15305891

AUTOMETER BOOST GAGE
If you have an AutoMeter Boost gage you already have a GM 3.0 BAR MAP sensor installed. All you have to do is connect the signal wire from the MAP sensor to the EGRT input on A22. (Only connect the signal line, not the ground.)

MOTOROLLA MPX4250AP MAP SENSOR
You can also use a Motorolla MPX4250AP 2.5 BAR sensor but you will have to either solder or find a suitable connector for the small leads and provide some mechanical protection for the sensor. (Consider using a .100" connector for easy attachment / service.)



PINOUT
PIN1 - Vout (Signal) Note: Pin 1 has notch on pin
PIN2 - GND
PIN3 - +5V
PIN4 - NC
PIN5 - NC
PIN6 - NC

ORDERING INFO
http://rocky.digikey.com/WebLib/Moto...A%20SERIES.pdf

Exact part number is MPX4250AP-ND. It is available for under $20 directly from DigiKey.


HISTORY
Boost signal on ECU-EGR input for logging

MMCd V1.6F posted 3/17/04
http://www.3si.org/forum/attachment....chmentid=35334

More MMCd info / Latest versions
MMCd New Features


Clint

[skunkworks]

Nice work. I just noticed I was using verison 1.4. Just installed 1.6e and going to give it a try on my lunch hour. Looks like a map sensor is on the "things to order list".

thanks
sam

[cbatters]

Originally Posted by samco

Nice work. I just noticed I was using verison 1.4. Just installed 1.6e and going to give it a try on my lunch hour. Looks like a map sensor is on the "things to order list".

thanks
sam

Couple things to try during lunch...

1. When you turn off your car, the Palm will automatically power off within ~10 seconds. Pressing F4 (right hand button) after you start your car will automatically un-pause the unit and start scanning.

2. Try programming O2 alarms for any voltage < .85 V Previously the O2 alarms were useless because the alarm would always go off during closed loop operation. Now the O2 alarms are gated with TPS > 80% so they are disabled during closed loop operation / deceleration.

(I believe Shiver / Chris has implemented this in the most recent version of his SW. Pretty sure PocketLogger does not have this function.)


Clint

[skunkworks]

The turning off is great. I didn't even notice it. I shut the car off and went to do some banking came back out and started it up and drove. I looked and the abs light wasn't on like it was when I would forget to unplug the cable. very cool. turned it back on and strarted datalogging again.

sam

Originally Posted by cbatters

Couple things to try during lunch...

1. When you turn off your car, the Palm will automatically power off within ~10 seconds. Pressing F4 (right hand button) after you start your car will automatically un-pause the unit and start scanning.

2. Try programming O2 alarms for any voltage < .85 V Previously the O2 alarms were useless because the alarm would always go off during closed loop operation. Now the O2 alarms are gated with TPS > 80% so they are disabled during closed loop operation / deceleration.

(I believe Shiver / Chris has implemented this in the most recent version of his SW. Pretty sure PocketLogger does not have this function.)


Clint

[skunkworks]

Did anyone ever come up with a way to convert the log files into text files or something usable?

thanks
sam

[cbatters]

Originally Posted by samco

Did anyone ever come up with a way to convert the log files into text files or something usable?

thanks
sam

Check the MMCd thread for the prototype converter. I had some stability problems but it did a good job of converting the logs.



Clint

[skunkworks]

Originally Posted by cbatters

Check the MMCd thread for the prototype converter. I had some stability problems but it did a good job of converting the logs.



Clint

Did you come up with a wiring diagram? I would rather just hack into the harness to hook it up. I am thinking that I will use it instead of trying to find a place for a gauge. MBC here I come!! (although I have a guage coming )

thanks
sam

[skunkworks]

never mind - I just read it again.

thanks
sam

[cbatters]

Originally Posted by samco

never mind - I just read it again.

thanks
sam

You can put the MAP sensor inside the car if you had already run the boost vacuum line into the cab by tapping into the signals at the ECU. However, it is actually easier to wire it up under the hood where all of the signals and vacuum connections are easily accessible.

MAP sensor / Palm is an interesting alternative to installing a dedicated turbo gage and offers the option of alarms and logging.

In the brief time I hooked up a manual goost gage, I found if difficult/dangerous to monitor boost while at WOT. With the logger, I can focus on driving with alarms set for O2, Knock, INJD and Boost and then review data after the run.

NEXT PROJECT
Next thing on my list are some mods to the MMCd SW (peak / log triggers) and an interface for adding additional instrumentation to the MMCd logger.

New inputs would include:

o Boost
o EGT
o Wideband O2
o Speed
- MPG
- 0-60 timing
- AWD HP
o Intake Manifold Air Temp
o Fuel Pressure
o Oil Pressure
o Others


Clint

[skunkworks]

Nice work

My thoughts exactly.
Mainly going to be using it to set the mbc anyway then after that it will be a log with alarms. My stock boost solenoid only works about 70% of the time.

I didn't think there was a wiring diagram until I reread your first post and saw -
+5V - TPS Connector (Green/White)
Ground - EGTR Connector (A22 - Black)
Signal - EGTR Connector (A22 - Green/Black)
that is all I needed. I am also going to mount it under the hood. I ordered the 2.5bar sensor from digikey but it will not be in until the end of the month.
Really quit excited about it.

Originally Posted by cbatters

You can put the MAP sensor inside the car if you had already run the boost vacuum line into the cab by tapping into the signals at the ECU. However, it is actually easier to wire it up under the hood where all of the signals and vacuum connections are easily accessible.

MAP sensor / Palm is an interesting alternative to installing a dedicated turbo gage and offers the option of alarms and logging.

In the brief time I hooked up a manual goost gage, I found if difficult/dangerous to monitor boost while at WOT. With the logger, I can focus on driving with alarms set for O2, Knock, INJD and Boost and then review data after the run.

NEXT PROJECT
Next thing on my list are some mods to the MMCd SW (peak / log triggers) and an interface for adding additional instrumentation to the MMCd logger.

New inputs would include:

o Boost
o EGT
o Wideband O2
o Speed
- MPG
- 0-60 timing
- AWD HP
o Intake Manifold Air Temp
o Fuel Pressure
o Oil Pressure
o Others


Clint

[cbatters]

New thread regarding MMCd enhancements.

MMCd New Features

[BLACK94TT]

subscribed....

[LeMoN1438]

Can you make this a little bit more clear for me? You can hotwire something to go into the unused port to input values into the ecu, or does it take values from the ecu and output it?

[cbatters]

Originally Posted by LeMoN1438

Can you make this a little bit more clear for me? You can hotwire something to go into the unused port to input values into the ecu, or does it take values from the ecu and output it?

Please re-read the first post ..... description is pretty simple / clear (provided you are already familiar with data logging. Otherwise you may want to do some searches/reading on datalogging.

Installation is on par with an A/F gage. You need to identify a couple of wires but there are only 3 connections.

MAP pressure is great for troubleshooting / alarming.





Clint

[BLACK94TT]

Clint,

I just realized that my electronic Autometer boost gauge utilizes the GM map sensor. Can I tap its signal wire and take it to A22-green/black? And do the same with its ground, going to A22-black?

Not knowing enough about electronics, will tapping the already in use sensor degrade the signal causing erroneous readings at both the gauge and logger?

Looks like I'm over here now.

[cbatters]

Originally Posted by BLACK94TT

Clint,

I just realized that my electronic Autometer boost gauge utilizes the GM map sensor. Can I tap its signal wire and take it to A22-green/black? And do the same with its ground, going to A22-black?

Not knowing enough about electronics, will tapping the already in use sensor degrade the signal causing erroneous readings at both the gauge and logger?

Looks like I'm over here now.

Short answer - Only connect the signal line, not the ground line. More details below.

SIGNAL LINE
Output impedance of the GM map sensor is quite low and the input impedance on the ECU is relatively high so it should not load the MAP output. (Autometer gage input should also be a relatively high input impedance.)

GROUND LINE
This one is a bit more complicated. Depends on what "Ground" you used for your autometer install. If you used "Signal Ground" of the ECU you are all set and there is no need to connect the ground lines.

And if you used a different "Gound", you still don't want to connect the ground wire because this can form a "ground loop" where current is flowing in the ground lines.

Quick DC measurement between Ground of the MAP sensor and Sensor Ground of the ECU A22-black will tell you how much error you would have. (ECU input has 8 bits of resolution so a .020 volt error will produce a 1 bit or ~.2 PSI error.)

SIMPLER EXPLANATION (No DVM required)
Start car and observe Autometer pressure at idle. Connect signal wire of MAP sensor to EGRT input.

1. Note whether there was any change in Autometer gage reading

2. Compare pressure of Automater gage and the display on the logger. If they are within +/- .2 PSI you are good to go.


NOTE - I will add a note at the beginning of this post to highlight the fact that if you already have an AutoMater Boost Gage, you can have boost logging for the cost of about 36" of 18 gage wire and a couple crimp on connectors! PICS of your AutoMeter install would be appreciated.

[skunkworks]

I have been meaning to post this here. This is my install using the digikey 2.5 bar sensor.
http://rocky.digikey.com/WebLib/Moto...A%20SERIES.pdf
It has been working great. It is a temperary perminant install

[cbatters]

Originally Posted by samco

I have been meaning to post this here. This is my install using the digikey 2.5 bar sensor.
http://rocky.digikey.com/WebLib/Moto...A%20SERIES.pdf
It has been working great. It is a temperary perminant install

LOL - "TPI" - Temporary Permanent Install

I'll have to post my "TPI". Given the low mass of the sensor, I didn't bother with the tie-wrap - the sensor is just suspended from the vacuum line.

One note about the Motorolla sensor - probably a good idea to provide some protection against water/oil infiltration. I wash my engine on a pretty regular basis and have not had any problems with the Motorolla sensor with just some electrical tape wrapped around it for protection.


Clint

[BLACK94TT]

I don't remember exactly where I grounded the Autometer gauge. I guess it doesn't matter anyway, since you say the only connection I'm concerned with is the signal to A-22. I have no idea why A-22 doesn't even need a ground.

I'm going to check this out tonight. To be able to log boost will be a huge help when tuning. I'd like to go out there right now and try this.

I'll post back with results.

[cbatters]

Originally Posted by BLACK94TT

I don't remember exactly where I grounded the Autometer gauge. I guess it doesn't matter anyway, since you say the only connection I'm concerned with is the signal to A-22. I have no idea why A-22 doesn't even need a ground.

I'm going to check this out tonight. To be able to log boost will be a huge help when tuning. I'd like to go out there right now and try this.

I'll post back with results.

The ground lead of A22 is ECU Signal Ground. You don't want to tie Chassis ground to Signal ground at the MAP sensor because it would create a ground loop. (Chassis ground and Signal ground should only be tied at one point which in this case is at the ECU.)

Low power instrumentation like A/F and Boost meters should be connected to signal ground. Incorrect ground reference of an A/F meter for example, could cause your A/F to change everytime you step on the brakes or turn on your blinkers.



Clint