My DIY Electronic Boost Controller

Talk EMS and Computer related performance

Postby Andy » Fri Jul 03, 2009 8:08 pm

Got it fixed. WG was sticking... blew air into it per BGB. I could see it moving, but not a lot. Feeling around back, the WG lever was hardly moving, if at all. Removed KO DP, it freed up. I could see where the lever had been dragging, there was just a tiny little scratch on the DP in that area. Anyway... Went for a ride, it's running with the MBC and rolls right up to 10 lbs, I'm sure higher once I get under the hood and adjust the MBC. (for the last time or two I hope) The idle, is better, very little vibration. she's happy.

Next steps....
Set up the Arduino and laptop again, log data with the MBC.
Remove MBC, switch back to ECU controlled plumbing.
Log data with Arduino of ECU controlling boost.
Log data of the Arduino controlling boost.

Members don't see the above ad. Register now - it's free!
Club Member
Posts: 330
Joined: Sat Oct 30, 2004 12:50 pm
Location: Ohio

Re: My DIY Electronic Boost Controller

Postby Pechin0351 » Thu Dec 09, 2010 2:54 am

Hey Andy
I was curious if you are willing to share your arduino sketch of your controller that you made? I have been working on an Arduino Mega to make a bunch of crap and I would love to utilize this as well! At the moment I am putting together 3 digit 8 segment displays to use as some gauges for IAT and oil pressure plus my heat exchanger temp. Based on the IAT and heat exchanger, I am controlling my IC pump through PWM. I have a few more digital inputs and I have wanted to try controlling my boost this way. So, do you feel like sharing your creation?
I do solemnly swear that I will support and defend the Constitution of the United States of America against all enemies, foreign and domestic; that I will bear true faith and allegiance to the same. So help me god!
Club Member
Posts: 229
Joined: Wed Apr 23, 2008 5:11 am
Location: Auburn, CA

Re: My DIY Electronic Boost Controller

Postby Andy » Fri Dec 10, 2010 4:27 am

Sure, give me a day or two to clean it up a bit, add some comments, etc.

Keep in mind you would need the same LCD and hardware as I'm currently using for the sketch to work for you.

Updates.... since it's been a while.

- My turbo will only push about 10 lbs of boost, which I think is due to a worn waste gate not closing tight. (maybe I should "wire it shut" to test it...) This is probably the key reason why there haven't been any recent updates.

- The 165 has an extended JDM wiring harness and the conversion did not work for the rad fan. The Arduino now does that for me. Much like the boost control, if temperature is over the set point I use a transistor to ground out the wire going to the stock sensor from the relay. Then, keep the fan on for at least 20 seconds.

- I got the WBO2 output feed into the Arduino working. For $19 I added a generic NB sensor to feed the ECU. Then, took the WB's ECU feed to the Arduino and remapped the WB to 0-5 Volts.

- I wired #1 injector through a 6v zenier diode, plus a couple other diodes to bring the voltage down to 5 volts and then to pins 2 and 3 to detect RPM and injector duty. This is not working yet. I see a constant voltage and thus not detecting any drop to zero to count and time the pulses.
Note: I have considered tying wire this to the ECU's Turbo VSV wire and then logging the on/off cycles. This hopefully, would identify if the ECU is using PWM or not.

Earlier I mentioned the LM3914 chip, This is how I picture that working.

My "DIY Boost Controller Version 2"

- In the above diagrams, assume the LM3914 is calibrated for "1 lb of boost per pin" and the LM34 will be set for "Bar" mode.
- The Arduino has it's first two pins HIGH, going into the AND gates for 8 lbs and 9 lbs, thus the boost limit is "Set" for 8 lbs.
- In the first diagram the LM3914 is seeing 5 lbs of boost so the first five pins are HIGH and are marked with with "red". Also, because boost is above 2 lbs the VSV is taken to ground.
- Each diagram after the first is "+1 lb" of boost, from 6-10 lbs.
- Below 2 lbs of boost, there would be no path way to the TIP102, so the WG would be closed.
- 6 Lbs would be my lowest "Set" point
- At 8 lbs of boost, or anything above that, the "Set" point, the VSV is released from ground.
- Pin 10, or 10 Lbs is hard wired as the "Max", or safety catch... at 10 lbs (you need it).
- The Arduino also could be wired into the 'AND' gating as a "sofware override" to limit boost, IF... cold engine, TPS is closing, IC heat soak, and/or put 50% PMW on the TIP102 at the boost set point minus 1 lb to start limiting boost just before actually hitting the set point, etc. (not shown above diagrams)
- This could be implemented w/o an Arduino. Just, substitute in "switches" to set your boost level.
- Two or more LM34s can be "stacked" to get a wider range and/or better resolution.
- You could also drive LEDs and have an LED boost gauge as well as control of it. Add another LED to monitor the signal to the TIP102.

Why use an LM3914?
- Because it's all hardware, the LM34s reaction time is instantaneous. If your Arduino is monitoring/logging data from other sensors that all takes time and the boost can spike quite fast. This design eliminates time issue by moving the control loop into hardware.
- It's cheap, substitute manual switches for the Arduino to control the set point and the it's probably the worlds cheapest EBC.

Links: (LM3914 wire up details, replace their MPX5100 pressure sensor sensor with the ECU PIM signal and tweak resistors if needed for voltage range) (LM3914 datasheet) (NAND Gate description) (AND Gate description)

Does it, Will it work?
- It's the same control logic I did in software with the Arduino, but done with hardware.
- I've already wired up 2, stacked LM3419's to PIM giving me 10 LEDs for vacuum to about 22 inches and 10 for boost to about 14 lbs.
- Don't know, haven't wired it up yet. I need to get some AND and NAND chips.
- I think it will work, but I've never done anything with logic chips like this before. Anyone see any reason why it would not work?

Club Member
Posts: 330
Joined: Sat Oct 30, 2004 12:50 pm
Location: Ohio

Re: My DIY Electronic Boost Controller

Postby Andy » Sun Jan 09, 2011 7:27 pm

Finally... see attached file.
It's actually grown into more than just boost control.

When I started this there was nothing like it on the net.
Today, Google: arduino turbocharger boost controller

Arduino Boost Controller V7.c
Arduino Boost Controller
(45.57 KiB) Downloaded 317 times
Club Member
Posts: 330
Joined: Sat Oct 30, 2004 12:50 pm
Location: Ohio


Return to EFI Corner

Who is online

Users browsing this forum: No registered users and 1 guest