Hack Correlation

Living close to a densely populated area means that it's hard to do consistent testing without spending a lot of fuel, which is also expensive. Nevertheless, I took the pen&paper approach and started working my way from the basics. I studied all the Bosch sensors from this page , used a bit of common sense and figured out that my sensor is a Bosch 0281002691, or similar, with a 180 MPa (26000 psi) nominal rating. This might be wrong but It's a good place to start. I've already used Torque and my multimeter to get some data and it seems to fit with the sensor I've chosen. It might be wrong, but so far it clicks into place. Using the data I've gathered I've created a simple JS page that shows some logs and tries to simulate what my module (and sensor) does: https://jsbin.com/goyavabuju/edit?html,output (Note that this is the HTML/JS result after I did the interpolation.) So the basic function is: the ECU commands the pump, this delivers a pressure...

If you are following the project you might've seen that the new source code for the firmware and (Android) client application are up: Arduino firmware:  https://github.com/ligius-/DieselTuningBox Mobile UI:  https://github.com/ligius-/DieselBoosterClient With that out of the way, I've had about a month of testing with the new prototype and several months already with the old one. The definitive result is that there are significant fuel savings. Outside city limits I now get better than 6L/100km, at highway speeds (130 km/h) better than 6.5/%. I believe the highway consumption can be further improved but I haven't used the car so much lately to be able to fine-tune the settings. Previously I would get 7.6L/100km at best on country/county roads and 7.4/% on highways. So that would be a 12% mileage increase on highways and 21% on slower roads. Inside the city is where the story changes since that's where I did most of my driving and had time to tune the pa...

As I wrote in the previous article , the barebones design has been through some basic testing - 500km mixed environment driving - and has been mostly successful so far. I had a suspicion that the output impedance of the circuit must somehow match a known impedance, but was not sure which. The clue was that the RaceChip unit raised city consumption by 5-15% even though it had no effect during the bench testing. Here's a datasheet for a similar Bosch pressure sensor: http://rb-aa.bosch.com/boaasocs/index.jsp;jsessionid=A20738712FCFB9E51CA919DD7D2F9E91.sundoro2?ccat_id=275&prod_id=516 For testing they are using a pull-up resistor, so on the input side of the ADC the same circuit must be simulated in order to drive the sensor. I used a 10k resistor, but perhaps even the internal pull-up could work. At the DAC/PWM output I found out that a 1.5k resistor was too large and could not sink the ECU input line low enough. With a 10ohm resistor it seemed to work fine, perhaps 47oh...

There are many variables needed to get a reliable product, so while taking a break from the ISO automotive requirements I thought of playing with a barebones design - just an Arduino, an HC-05 module and perhaps a few passives. Concept - this is similar to what the boxes on the market do - read the value on ADC, output the modified value with PWM. I'm using an Arduino Nano for this, took about half a day including the 'preview' spreadsheet. Nano pinout: Vcc to sensor supply (5V), from ECU GND to sensor ground A0 the output from the sensor Pin 9 goes to ECU (former sensor data) TX goes to RX of HC05 RX goes to TX of HC05 Notes: A0 should probably be pulled up to Vcc through a 1k resistor, I haven't tested this yet. Perhaps the Arduino weak pull-up would work. Pin 9 (PWM output) should go through a resistor and capacitor connected to ground, 1k with 0.3u looks good in my tests. The first two pictures show the Android phone connected to th...

As seen from my previous post and the sources enumerated in it there are several competing designs on the market that basically achieve the same thing - apply a negative offset to the rail sensor voltage. Since none of them offer a desirable amount of control (for the price) I'm open sourcing an own design. Goals: full programmability - curves, upper and lower threshold limits telemetry reasonably fail-safe MCU agnostic - as far as possible preserve the original waveform signal easy to make - should not require exotic or expensive components The overall architecture is simple: read sensor data into the microcontroller, process the signal, send an analog (PWM) signal out. Disclaimer: this is probably not road-legal in many countries (missing certifications) and it might break the car subject. I am not responsible if anything bad happens, do it at your own risk. However, it's not all dark, as I've already written there should be no damage as the unit still ...

See my first article for a short review and teardown: http://hackcorrelation.blogspot.de/2016/02/inside-stuff-racechip-car-tuning-thingie.html First off let me start by saying I consider this fair use, as the instructions and website do not explain what the settings do, how the unit actually functions and what effects it can have. The description below refers to a single-channel Diesel engine (single common rail). Settings First off, most of the users will just want the simple explanations, here's a graph that should be in the manual: The chart above shows 4 possible settings and their effects. The first rotary encoder controls how much 'extra power' is requested. See 9E vs. BE vs. 4E The second rotary encoder controls the RPM high range (endpoint). See BE vs B7. The encoders go from 8 (minimum) through 9, A, B, C, ..., F, 0, 1 ... 7 (maximum).

I bought my unit half a year ago, so you can say I have plenty of experience using it. It functions as a man-in-the-middle between the ECU and the injectors. I believe it alters the injectors' on-time and perhaps even the timing with regard to the TDC. See also:  http://hackcorrelation.blogspot.de/2016/04/racechip-tuning-box-part-2-reverse.html Short review I wanted to lower the consumption of my 3L V6 diesel engine to slightly more frugal values, don't care as much about power. Sure, some extra low-end torque would be nice as I feel my particular car is lazy in shifting up. Well, to my surprise, the unit actually does something, so it's not just a random box a la OBD-tuners. By the way, you cannot tune an engine through OBD, the engine protocol is filtered out by a gateway. Just some diagnostics are allowed through. The highway mileage improved from 8L/100km (30 US MPG, 35 UK MPG) to less than 7L/100km. With the default settings (the unit can be adjusted) the l...

In the first part I identified the problem leading to the unit overheat: a design decision consisting of dropping more than 10 Watts on a couple of 3W resistors. I've thought of several ways to address the issue: change the 5V rail to a switching design put bigger resistors and mount the 7805 on a heatsink have a switching or linear preregulator that drops 12V to a more manageable 7-9 Volts I have a few switching supplies bought from ebay at around 2-4$ each based on the LM2596 reference design. However they might be noisy and I'm not sure how well they handle high loads. Should be good enough for charging the USB and anyway the 1.8V and 3.3V lines go through linear regulators first, cleaning them of noise. The bigger resistor solution would also work but I did not have any 10W resistors at hand and I'm not sure they would fit in the small space between the CD tray and the case. Since I have a few LM7808 and LM7809 from scrap I decided to go with the third solut...

I've bought a somewhat cheap car MP3 player a few years ago on the reason that it had Bluetooth support and nice amber lights to complement the design of my E39. I understand some people will come here looking for a wiring diagram so I should start with that first: Model: Watson CRC8060MU I've always had the issue of not being able to charge anything from the USB port or the unit resetting with some strange USB sticks. Also, the unit lost its settings when cranking the engine with a low battery while it was playing music. After the jump I start taking it apart to see how it works and what can be done to address the issues.