Dual throttle bodies
#1
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Dual throttle bodies
Just wondering if anyone has done a dual TB setup with 8 pin TB's?
I'm aware of the OZMOS kit. But was thinking it could be done with an H bridge driver.
Any thoughts?
Chris
I'm aware of the OZMOS kit. But was thinking it could be done with an H bridge driver.
Any thoughts?
Chris
#3
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It would have to be DBW based on the data provided.
An H bridge in it's basic form is to be able to swap polarity on a motor easily. The dual DBW systems are more than that. You are controlling two stepper motors, sending throttle position and fault data back to the PCM.
The OZMO is one of the few/best options outside running an aftermarket PCM that supports dual TB's.
An H bridge in it's basic form is to be able to swap polarity on a motor easily. The dual DBW systems are more than that. You are controlling two stepper motors, sending throttle position and fault data back to the PCM.
The OZMO is one of the few/best options outside running an aftermarket PCM that supports dual TB's.
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To simplify things when using an h-bridge, only 1 set of TP sensors would be providing feedback to the ECM.
In some industrial application, the h-bridge is used as a power amplifier, which is why I have went down this road.
In automotive applications, the ECM has a PWM (pulse width modulator), which then feeds a bridge rectifier and then onto the TB servo motor.
Simple enough.
The problem I'm running into, is interrupting the PWM signal before it goes to the initial bridge. If there is a way to get that signal to an H bridge, I'm confident it can be done. An h-bridge can be controlled with a PWM signal, I'm not clear on whether the signal to the throttle body can do this or if it has too much amplitude.
I'm not an engineer, nor am I an electronics tech. I'm looking for a simple solution to a complex problem.
Running duals would definitely up the cool factor on anything.
Chris
In some industrial application, the h-bridge is used as a power amplifier, which is why I have went down this road.
In automotive applications, the ECM has a PWM (pulse width modulator), which then feeds a bridge rectifier and then onto the TB servo motor.
Simple enough.
The problem I'm running into, is interrupting the PWM signal before it goes to the initial bridge. If there is a way to get that signal to an H bridge, I'm confident it can be done. An h-bridge can be controlled with a PWM signal, I'm not clear on whether the signal to the throttle body can do this or if it has too much amplitude.
I'm not an engineer, nor am I an electronics tech. I'm looking for a simple solution to a complex problem.
Running duals would definitely up the cool factor on anything.
Chris
#5
From my understanding the problem with this will be that the PCM will see the increased voltage draw of the 2nd TB and send you into REP mode. That's why Ozmo's setup is successful, their controller reads the voltage to the master TB without the PCM seeing any additional draw.
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Does the ECM actually monitor voltage to the TB. If I'm not mistaken, the TP sensors and APP are the only thing monitored. An H bridge or even a half bridge is operated sort of like a relay. The pulse controls the internal switching. High amplitude is on, low is off. A seperated power supply actually runs the motor.
So, with that being said, I don't see why an h bridge couldn't be slaved off of a TB circuit. With that being said, an independent power source would be needed in order to drive the circuit. Most h bridge control boards can operate off of a 12 volt input and have a 5 volt output.
After all that being said. Synchronizing dual TB's would be a nightmare. An open Plenum manifold would be ideal to help equalize air flow.
Of course, the ECM will need tuned for opening rate, etc...
So, with that being said, I don't see why an h bridge couldn't be slaved off of a TB circuit. With that being said, an independent power source would be needed in order to drive the circuit. Most h bridge control boards can operate off of a 12 volt input and have a 5 volt output.
After all that being said. Synchronizing dual TB's would be a nightmare. An open Plenum manifold would be ideal to help equalize air flow.
Of course, the ECM will need tuned for opening rate, etc...
#7
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I have no interest in dual TB's, other than academic, but I wonder if they will feed a common plenum or not. This would affect both the need and the way to gauge synchronization. Of course you could always manually link a DBW to an otherwise cabled TB without splitting or combining any electronic signals. The physical linkage would allow only one DBW signal set to control everything. That being said, it does sound fun to figure out the electronic control side of the situation, even if a bit unnecessary.
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I initially thought about a cable or mechanical linkage. The stepper motors are rather small in a throttle body. Not to mention, they drive the butterfly with plastic gears.
Then there is going to be some engineering and fab work involved in order to make it all work. When dealing with a vehicle that is already drive by wire, the electronic way seems better.
Then there is going to be some engineering and fab work involved in order to make it all work. When dealing with a vehicle that is already drive by wire, the electronic way seems better.