Bypassing Drive-By-Wire
11-08-2005, 06:17 PM
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Bypassing Drive-By-Wire
I want to know what exactly is needed to bypass the Drive-By-Wire. I please ask people to respond with theoretic/possible alternatives of doing so than rather posting "it's not worth it".
-To start off, what relationship is their between the ECU and the DBW?
-How will the ECU react to the change if it is done?
-What can be done to the ECU to not rely on DBW signal?
-To start off, what relationship is their between the ECU and the DBW?
-How will the ECU react to the change if it is done?
-What can be done to the ECU to not rely on DBW signal?
11-08-2005, 09:14 PM
#4
One of the many things you will have to overcome is the fact that the ECU uses the throttle body to establish idle. There is no idle motor on the Z, the ecu just changes the throttle angle to manipulate idle. It also uses the throttle to manage traction control.
After that, you have to figure out a way to give the computer a tps signal. I'm sure there are many other hurdles as well. If you really want to do it, you will need a stand alone computer.
After that, you have to figure out a way to give the computer a tps signal. I'm sure there are many other hurdles as well. If you really want to do it, you will need a stand alone computer.
11-10-2005, 01:11 PM
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youre going to need a tps (throttle position sensor), and maybe an iac (idle air control) motor.
the relationship between the ecu and dbw is a signal, most likely like a potentiometer or displacement transducer, where the voltage increases as you displace something
basically a 0-5V ouput that sends that same voltage to a motorized throttle to open accordingly.
you need an ECU diagram to fully determine what can be done.
but if you can mate the signal of the tps coupled with a cable (unless you are going a different route) to the ecu's dbw signal you might be able to wing it.
get that diagram.
actually...i think i have the service manual on my computer. its probably in there. if you need it let me know
-chris
the relationship between the ecu and dbw is a signal, most likely like a potentiometer or displacement transducer, where the voltage increases as you displace something
basically a 0-5V ouput that sends that same voltage to a motorized throttle to open accordingly.
you need an ECU diagram to fully determine what can be done.
but if you can mate the signal of the tps coupled with a cable (unless you are going a different route) to the ecu's dbw signal you might be able to wing it.
get that diagram.
actually...i think i have the service manual on my computer. its probably in there. if you need it let me know
-chris
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11-10-2005, 01:18 PM
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Originally Posted by SBT
but if you can mate the signal of the tps coupled with a cable (unless you are going a different route) to the ecu's dbw signal you might be able to wing it.
-chris
11-10-2005, 04:42 PM
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Originally Posted by Zexy
Now how can that exactly be done
not saying this is a cakewalk here, but assuming the ECU could potentially react the same to both of them, you might be able to pull that off.
im willing to bet that all that sensor has going to it is wires to read voltage (0-5V) which increases or decreases as the pedal is modulated. match the change in voltages to your in-bay unit and it might work
11-10-2005, 05:27 PM
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That sounds like a plan. Might be worth it to try it out.
I have gathered from a individual that Mini Coopers eliminate their DBW system to convert to cable throttle for the use of an ITB system(EDIT: With a standalone
). I might just visit the forum and see what exactly they pull off and how. May be somehow similar?
I have gathered from a individual that Mini Coopers eliminate their DBW system to convert to cable throttle for the use of an ITB system(EDIT: With a standalone
). I might just visit the forum and see what exactly they pull off and how. May be somehow similar?
Last edited by Zexy; 11-10-2005 at 05:31 PM.
11-10-2005, 05:56 PM
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-"The pedal is connected to a spring-loaded sensor to approximate the feel of an accelerator cable and the signals generated are sent to the engine control unit and from there to an electric motor which operates the throttle."
-http://www.e46m3performance.com/tech/throttle/
From the looks of how it all comes down the ECU itself controls the throttle position. The throttle position is not sent to the ECU and does not have control OVER the ecu like a cable throttle system.
Seems like standalone it is until some other idea is possible.
-http://www.e46m3performance.com/tech/throttle/
From the looks of how it all comes down the ECU itself controls the throttle position. The throttle position is not sent to the ECU and does not have control OVER the ecu like a cable throttle system.
Seems like standalone it is until some other idea is possible.
11-11-2005, 08:20 PM
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Originally Posted by Acree
why exactly would you want to f*ck with it? no reason to reinvent the wheel, and so far i havent seen you explain why you would want to go through all the trouble.
+1
11-11-2005, 09:42 PM
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Originally Posted by Acree
why exactly would you want to f*ck with it? no reason to reinvent the wheel, and so far i havent seen you explain why you would want to go through all the trouble.
11-11-2005, 11:07 PM
#18
Originally Posted by Zexy
By the way you write your posts it looks like your highly aggravated and responding with smart azz comments. Get off my thread.
oh yeah, and i can post as many replies on your thread as i want, so good luck with that one capiton.
11-12-2005, 03:36 AM
#19
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Just a couple of experiences I have had with the DBW.
I wanted to have a super consistent launch for bracket racing with street tires in an auto. The series I was entered into consisted of 5 races with a $1k purse for each race.
What I wanted was a launch throttle opening that wouldn't spin the tires and then at a preset RPM after the car left the line, switch to WOT automatically for an automated consistent launch.
So the DBW throttle pedal consists of 2 variable resistors each sending a signal to the ECU one about 1/2 the voltage of the other. These 2 voltages have to be in sync with each other or the ECU throws an error.
I kept trying resistors from the power supplying the signal until I found 2 that would allow me to launch without spinning. I connected each of those resistors to its own relay to the ECU. At the press of a button it would then go to that present throttle opening and stay there without touching the pedal.
Then I connected the full voltage signal to 2 more relays so that when energized it would send full throttle to the ECU.
To make it all work automatically I connected the 1st set of relays to a manual switch for the initial launch. The 2nd set for WOT was connected to an MSD 8969 Digital RPM switch that I could program to any RPM and connect the 2nd set of relays.
So, on initial launch it was set to approx 25% throttle opening and then at approx 3500 RPM the RPM switch sent the WOT setting to the ECU.
Worked very well, however I never won any money but it wasn't the fault of that setup it worked great it was my R/T's that killed me.
Now I am working on a project to put a 3.5 in a car with no DBW so i have had to convert the throttle body to cable. This was pretty simple and although it won't work for a DBW car, I just had to show my crude butchering job.
I wanted to have a super consistent launch for bracket racing with street tires in an auto. The series I was entered into consisted of 5 races with a $1k purse for each race.
What I wanted was a launch throttle opening that wouldn't spin the tires and then at a preset RPM after the car left the line, switch to WOT automatically for an automated consistent launch.
So the DBW throttle pedal consists of 2 variable resistors each sending a signal to the ECU one about 1/2 the voltage of the other. These 2 voltages have to be in sync with each other or the ECU throws an error.
I kept trying resistors from the power supplying the signal until I found 2 that would allow me to launch without spinning. I connected each of those resistors to its own relay to the ECU. At the press of a button it would then go to that present throttle opening and stay there without touching the pedal.
Then I connected the full voltage signal to 2 more relays so that when energized it would send full throttle to the ECU.
To make it all work automatically I connected the 1st set of relays to a manual switch for the initial launch. The 2nd set for WOT was connected to an MSD 8969 Digital RPM switch that I could program to any RPM and connect the 2nd set of relays.
So, on initial launch it was set to approx 25% throttle opening and then at approx 3500 RPM the RPM switch sent the WOT setting to the ECU.
Worked very well, however I never won any money but it wasn't the fault of that setup it worked great it was my R/T's that killed me.
Now I am working on a project to put a 3.5 in a car with no DBW so i have had to convert the throttle body to cable. This was pretty simple and although it won't work for a DBW car, I just had to show my crude butchering job.
11-12-2005, 08:20 AM
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Originally Posted by Jime
Now I am working on a project to put a 3.5 in a car with no DBW so i have had to convert the throttle body to cable. This was pretty simple and although it won't work for a DBW car, I just had to show my crude butchering job.