8 > 2 
Dual throttle bodies
What type of signal drives the throttle body motor? I'm assuming it's a DC stepper motor that uses voltage on 2 terminals for movement in one direction and 2 more terminals for movement in the other?
If so, I'd think that a simple op-amp buffer circuit could take the voltage intended for the single TB, and buffer it and split it to drive the two throttle bodies. The computer can still get it's feedback info from one TB and never know about the 2nd one. I'm sure you'd have to do a custom tune to account for throttle position, etc, but in terms of just driving the two motors from one source, I really don't see that as being difficult.
If so, I'd think that a simple op-amp buffer circuit could take the voltage intended for the single TB, and buffer it and split it to drive the two throttle bodies. The computer can still get it's feedback info from one TB and never know about the 2nd one. I'm sure you'd have to do a custom tune to account for throttle position, etc, but in terms of just driving the two motors from one source, I really don't see that as being difficult.
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Joined: Apr 2008
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What type of signal drives the throttle body motor? I'm assuming it's a DC stepper motor that uses voltage on 2 terminals for movement in one direction and 2 more terminals for movement in the other?
If so, I'd think that a simple op-amp buffer circuit could take the voltage intended for the single TB, and buffer it and split it to drive the two throttle bodies. The computer can still get it's feedback info from one TB and never know about the 2nd one. I'm sure you'd have to do a custom tune to account for throttle position, etc, but in terms of just driving the two motors from one source, I really don't see that as being difficult.
If so, I'd think that a simple op-amp buffer circuit could take the voltage intended for the single TB, and buffer it and split it to drive the two throttle bodies. The computer can still get it's feedback info from one TB and never know about the 2nd one. I'm sure you'd have to do a custom tune to account for throttle position, etc, but in terms of just driving the two motors from one source, I really don't see that as being difficult.
It is completely possible to something along the lines of what you say but its really about the investment of time required and the return. Plus the legal issues. Plus getting it to operate within the factory envelope for throttle position/airflow/MAP etc etc.
And the challenge is keeping the blades in phase with each other. It really needs a single TB "emulator" that looks like a single TB to the ECM and throttle controller, but drives two TB's. Or simply a mechanical linkage that slaves off the main TB. Then fingers crossed the throttle position errors dont get out of hand and/or can be tuned out.
Yes that's one of the kinsler setups, carbon fiber throttle bodies and 2 fuel injectors per port. They also have an option for vertically oriented throttle bodies. I don't know what the setup costs but it must be a lot judging from the materials used and the fact that they don't even list the price on their website.
Most kinsler products are over priced in my opinion. I have been trying to make a dual setup similar to the viper or ferrari intake. I dont think its going to be that hard to hook the TB's up.
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How about instead of tryin to make them open at the same time, make them seperate but on the same throttle signal and only open one of them up and at about 50% throttle one of them will be at WOT then have the other one start to open until the throttle pedal is at 100% and both of them are at WOT. kinda like a primary and secondary 4brl carb but electronicaly controlled.
Been researching this and found a couple interesting examples.
First, this is a manifold from Ozmo with twin LS3 thorttle bodies. One has been modified to drive the other as a slave. I don't know if they are using a factory ECM:
www.youtube.com/watch?v=9xca3rly-0c
www.youtube.com/watch?v=fg_HhIVYHJE
Next, here are twin LS3 throttle bodies both being driven electronically from a Holley ECU. http://www.chevelles.com/forums/showthread.php?t=306080
First, this is a manifold from Ozmo with twin LS3 thorttle bodies. One has been modified to drive the other as a slave. I don't know if they are using a factory ECM:
www.youtube.com/watch?v=9xca3rly-0c
www.youtube.com/watch?v=fg_HhIVYHJE
Next, here are twin LS3 throttle bodies both being driven electronically from a Holley ECU. http://www.chevelles.com/forums/showthread.php?t=306080
On The Tree
Joined: Mar 2007
Posts: 129
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although i originally thought it would cause a fault code.. i have seen 2 LS2 throttle bodies wired up together on a factory E38 ecu with no problems.. just used one as the original 6 pin wires and the 2nd throttle body just shared the +ve and -ve motor wires.
Do you know if these are feeding a PWM signal to the throttle body motor? Very interesting if it works okay without position feedback on the second TB. I think I would put a following circuit in to prevent drawing too much current from the ECU.