[Smee]

What software and where from do i use to data log? i want to see fuel rail pressure and boost pressure

cheers
lee

[Ajs_435d]

Torque on android and bluetooth obd

[Smee]

Oh really. Didn't think that would work. I'll have to buy another obd tool as last one went in bin

Have you tried it?

[Ajs_435d]

For IAT yes

[Smee]

AJS did you manage to get Fuel rail pressure working mine arrived today and it wont have any of the fuel rail ones working

[Smee]

attached

[Darth Helmut]

Lee, I was thinking since you messaged me. Have you tried DashCommand app? Might narrow down if its Torque app or whether the OBD is actually sending the info. Hopefully my ELM 327 arrives tomorrow and I can check with both.

[Smee]

let me know as i dont have dash commander and not gonna waste £10 if it doesnt do what i want it to. its the only feature i want. fuel rail pressure

[Darth Helmut]

Will do mate. I just have the free app DashCommand at the mo. If it look like it'll do it on the free app, I'll stick with that. I'm assuming the ELM 327 can use any/most apps and not just Torque?

[NISFAN]

What's the fascination with fuel rail pressure?

[Darth Helmut]

Originally Posted by NISFAN

What's the fascination with fuel rail pressure?

With tuning boxes, its a bit of piece of mind we're not over pressuring the system

[Ajs_435d]

It depends how the tuning box works you might find it doesn't directly tell the ecu to increase pressure. Not effect a PID or pre process the signal to keep the stock ecu happy. Generally a tuning box cheats.

[JLR1969]

Am watching with interest you pair of smart arses, I managed to retune the Freeview box which is about my limit.

I now have Quest Red!

[NISFAN]

Originally Posted by Symbol-formerly Mr Helmut

With tuning boxes, its a bit of piece of mind we're not over pressuring the system

Well you do know the way a tuning box works is to intercept the real values and report back 'doctored' values.

.......and the OBD data comes from the ECU, i.e doctored values.......so you're being fooled as much as the ECU is

[Darth Helmut]

You're quite right mate. I guess its understanding where abouts the pick off from the box reports to. Values in to it will be doctored but there may be a live 'actual' that comes from the rail. Will report back!

My box is off at the moment (due to getting new wheel fitted at dealer) so when my ELM 327 arrives tomorrow, I'll firstly see if DashCommand reports it and secondly, if it does, see what the delta is (if any) when I fit the box back in.

[NISFAN]

Originally Posted by Symbol-formerly Mr Helmut

You're quite right mate. I guess its understanding where abouts the pick off from the box reports to. Values in to it will be doctored but there may be a live 'actual' that comes from the rail. Will report back!

My box is off at the moment (due to getting new wheel fitted at dealer) so when my ELM 327 arrives tomorrow, I'll firstly see if DashCommand reports it and secondly, if it does, see what the delta is (if any) when I fit the box back in.

The ECU, is the device that turns analogue engine sensor readings into CAN data, so there is zero chance of an OBD reader picking up raw analogue data, it only understands CAN.

[Smee]

Nisfan

how sure are you where it getting logged?

I would of thought there is a sensor on yhe fuel rail as this is what bmw check when they check and see if a car is mapped.

the information is there somewhere but if that is available from the obd with this device I do not know.

in torque there is 2 fuel rail pressure sensors (neither work lol) which I presume is pre and post sensor. I know the car requests X and the tuning box sends Y but I want that sensor after Y.

also anyone know what the stock boost pressure is?

[NISFAN]

Originally Posted by Smee

Nisfan

how sure are you where it getting logged?

I would of thought there is a sensor on yhe fuel rail as this is what bmw check when they check and see if a car is mapped.

the information is there somewhere but if that is available from the obd with this device I do not know.

in torque there is 2 fuel rail pressure sensors (neither work lol) which I presume is pre and post sensor. I know the car requests X and the tuning box sends Y but I want that sensor after Y.

also anyone know what the stock boost pressure is?

22.5 psi ???? Now there's a coincidence. That equates to 1.55 bar, which happens to be the max reading my logger records too.
My thoughts are that the sensor that gives this boost pressure reading maxes out at 1.55bar.
Next time you drive your car, you'll see that the boost pressure quickly climbs to 22.5 psi and then stays flat. Maxed out sensor, as there is no way boost can be controlled that finely

I suspect there is another sensor that reads boost, but it's not accessible via OBD.

[Smee]

Originally Posted by NISFAN

22.5 psi ???? Now there's a coincidence. That equates to 1.55 bar, which happens to be the max reading my logger records too.
My thoughts are that the sensor that gives this boost pressure reading maxes out at 1.55bar.
Next time you drive your car, you'll see that the boost pressure quickly climbs to 22.5 psi and then stays flat. Maxed out sensor, as there is no way boost can be controlled that finely

I suspect there is another sensor that reads boost, but it's not accessible via OBD.

yea it hits it quick and flat lines for sure as i nearly rear ended the car in front which thinking what is that doing lol

is the 335d engine from the e90 the same engine? if so maybe some of the PID's will work from those on our cars?

apparently fuel rail pressure on e90 335d is

pid 016D
formula ((D*256)+E)*0.1

[Smee]

if the PIDS are the same here is the link i was reading

http://www.e90post.com/forums/showthread.php?t=1118429

[NISFAN]

Originally Posted by Smee

if the PIDS are the same here is the link i was reading

http://www.e90post.com/forums/showthread.php?t=1118429

Ok, so those are to convert units or to better calibrate what the sensors are telling you through the device you are using to view them? I can understand that, as the ECU just needs to know scale of the value, whereas as we might want to know absolute values for comparison reasons. So for example, the ECU is not interested in how many psi of boost pressure there is, just wants to know on a scale of 1-10, where is it.

Can't help you there, I guess someone has used another known sensor and made up a correction table to make the BMW readings more user friendly and accurate. :