Rail Pressure Tuning Box

[eapen]

For understanding the technique behind Rail Pressure Digital Diesel Tuning Boxes, I bought one from an Italian seller - tuningestile . The seller claimed it has 64 bit processor & 32 K flash memory to process signals. I have not used the box yet.



Having learnt Electronics by self from my school days without undergoing any professional course per say, the first action item was to open the box out of sheer curiosity. When opened, it became clear to me the claims of 64-bit processor & 32 K flash memory are all hogwash. Though it's got 2x chips & a potentiometer knob inside for adjusting power levels, it is no way near what the seller claims to be.

[007]

old wine in a new bottle eh eapen?

[2Stroke Junkie]

old wine in a new bottle eh eapen?

Are you sure its a wine?

[eapen]

Yes 007 you are right. Old wine indeed - have to test out literally truth in the theory 'old is gold' pertaining to alcohols

Observations:
1)Observe the 2 SMD chips - 7 legs on either side, total 14. There are 2 print lines on the chip.
The First Line is the manufactuer batch code and the second line is the IC id = LM324 (the key)

LM324 is a Quad Op-Amp (Operational Amplifier) which is basically an analogue amplifier with non-inverting & inverting inputs
refer datasheet : LM324 Datasheet - electronic circuit | component | pinout


The foundation of Op-Amps was laid by IC 741

2)It has 5 zener diodes which serve to over-ride voltage manipulation after certain voltage - approx 3.5v

3)The power is adjusted via the potentiometer - varying resistance. To the left of the knob marked 0 & to the right 10.
0 - no power difference
10 - full power

Manufacturer instruction not to exceed 7 for street use.

[mclaren1885]

Why is anyone surprised? Hasn't it always been known that these tuning boxes were nothing but a fancy assortment of resistors and ICs? What matters is how they trick the ECU without throwing up CELs. A good tuning box will do precisely that without blowing up your engine.

For anyone with slight knowledge in Electronics, you can pull out any electronic device and say, wow that's so simple to make! That includes me too, when I saw a standalone ECU and knew someone in Peenya who could make an exact replica for 1/3rd the price I'd be paying shipping from abroad. Easier said than done.

Been testing rail pressure boxes for the last week or two on a Cruze. Pretty much goes without saying that they suck when compared to Injector Modulation boxes.

eapen - Did you try using Torque to see what rail pressures you are gaining with and without the box? Again, I think the Verna has a IM box? Then why the RPM box?

[007]

Hasn't it always been known that these tuning boxes were nothing but a fancy assortment of resistors and ICs?

that is like calling an engine a bunch of nuts, bolts and metal. I believe the point of the thread is to call the "64 bit processor, 32K flash memory" bluff that people use to jack prices up. whether or not the box does its job and how well it does is another matter.

[eapen]

Last time I inquired regarding Injector modulation PSI tuning box for Hyundai Verna I was conveyed that only Rail Pressure boxes are available.

It is a fallacy that Injector Modulation boxes are safer than Rail Pressure boxes. Diesel injector pulses 5 - 7 times (depending on engine manufacturer) per stroke to finely atomize diesel which is altered by an Injector Modulator. Over lap of the injection pulses using an injector modulator can cause excessive smoke or in extreme cases cause failed pistons, rings. Moreover the ECU loses complete control of the injectors failing to reduce fueling proportionately in case of excessive torque, high coolant/air temperatures, etc

Whereas in rail pressure modulation, the ECU still controls the injectors, and if the other parameters other than fuel pressure sensor voltage are exceeded then it will reduce fueling based on the ' Maps ' stored inside to protect the engine.

Search for Steinbauer Tuning box problems which is similar to PSI injector modulation Tuning Box, then you'll understand what I am trying to convey. I've had conversations with Digital Vampire on this subject and he can comment more on this.

[Digital Vampire]

Are both chips LM324? If yes, this must be some ridiculously simply contraption in the form of a voltage translator masquerading as an RPM TB. That said, I've seen RPM TB's with microprocessors (EngineCal for example)

[007]

Are both chips LM324? If yes, this must be some ridiculously simply contraption in the form of a voltage translator masquerading as an RPM TB. That said, I've seen RPM TB's with microprocessors (EngineCal for example)

so essentially, these potentiometer boxes increase rail pressure by a constant factor and boxes with microprocessors can use look up tables to vary the modulation based on real time inputs?

[Digital Vampire]

so essentially, these potentiometer boxes increase rail pressure by a constant factor and boxes with microprocessors can use look up tables to vary the modulation based on real time inputs?

True.
Without looking into the design, I'm hazarding a guess that the opamp box just adds/subtracts a fixed offset to the input signal determined by the potentiometer position.

uP/uC based TB's can do this more elegantly and non-linearly using an LUT (Look Up Table).
eapen Sir...Looks like the fuel rail connectors are the only high cost item in that entire design.
If there is indeed no uP/uC underneath that board, the rest of the BOM cost should be less than Rs.50.