Here why some people have issue with the larger TB. It has to do with how the TB is controlled. On the TL/S it is controlled by the TPS while the ZDX and TLSHAWD are controlled directly by the ECU.
long story short even with hondata it will not and cannot be fixed. Its a hardware problem not software.
original URL
https://www.hondata.com/forum/viewto...9efc7e9c23f7f5
Since people often swap to larger drive by wire throttle bodies, we tested Civic Si, TL Type S and ZDX throttle bodies for compatibility.
There are two types of drive by wire systems that Honda uses. One where the ECU drives the throttle body directly (Civic, TL, RDX) and where there is a separate throttle controller (S2000, TSX before 2007).
ECU driving the throttle body directly.
throttle-civicsi.png
throttle-civicsi.png (13.76 KiB) Viewed 156 times
ECU communicating with the throttle controller.
throttle-tsx.png
throttle-tsx.png (30.88 KiB) Viewed 156 times
All throttle bodies have two components - a DC motor to position the throttle plate, and a throttle position sensor to determine where the throttle plate is. The throttle position sensor has two resistive elements (A & B) for multiple redundancy. The motor is driven both open and closed by the ECU or controller, switching voltage across the motor using two sets of transistors.
Tests - Throttle Position Sensors
1. TPS A & B voltage
A. Civic Si
Closed 0.60 / 1.48 volts
Default position 0.85 / 1.67 volts
Open 4.00 / 4.20 volts
B. TL-S
Closed 0.62 / 1.50 volts
Default position 0.89 / 1.72 volts
Open 3.85 / 4.07 volts
C. ZDX
Closed 0.60 / 1.47 volts
Default position 0.90 / 1.72 volts
Open 3.97 / 4.17 volts
2. Throttle plate position
A. Civic Si
Closed 0.1%
Default position 7.8%
Open 105%
B. TL-S
Closed 0.0%
Default position 9.1%
Open 100.3%
C. ZDX
Closed 0.1%
Default position 9.5%
Open 102.6%
The TPS sensor for each throttle body works in the same way. The default position is different for the TL & ZDX throttle bodies.
Tests - Motor
1. Motor resistance
Averaged over 6 measurements, open direction and closed direction, using actual current for set voltage
A. Civic Si 2.85 ohms
B. TL-S 1.70 ohms
C. ZDX 1.35 ohms
2. Peak current @ 14V
A. Civic Si 4.9 amps
B. TL-S 8.2 amps
C. ZDX 10.4 amps
As the throttle body gets larger, the motors are higher torque / higher current. This is not proportionate to the throttle body opening area, as the ZDX throttle draws almost twice the current of the Civic throttle body.
Under real world conditions the throttle controller will vary the current to the motor in order to position the throttle plate. The current required to do this will be around the same for each throttle body (roughly 1 amp). However, the peak current is much higher on the larger throttle bodies. This is likely to be a problem if the transistors in the throttle controller shut down from over current or over temperature.
With the Civic Si / R18 ECU, the throttle controller uses a IC chip to drive the throttle body motor. The IC is rated at 5.0 amps continuous current, and has over current and over temperature shut downs. Switching to a throttle body which uses more than double the current is likely to overload the controlling IC.
Conclusion
Bigger throttle bodies draw more current, potentially overheating the controlling circuitry, causing erratic throttle operation and errors. This cannot be fixed by software.
long story short even with hondata it will not and cannot be fixed. Its a hardware problem not software.
original URL
https://www.hondata.com/forum/viewto...9efc7e9c23f7f5
Since people often swap to larger drive by wire throttle bodies, we tested Civic Si, TL Type S and ZDX throttle bodies for compatibility.
There are two types of drive by wire systems that Honda uses. One where the ECU drives the throttle body directly (Civic, TL, RDX) and where there is a separate throttle controller (S2000, TSX before 2007).
ECU driving the throttle body directly.
throttle-civicsi.png
throttle-civicsi.png (13.76 KiB) Viewed 156 times
ECU communicating with the throttle controller.
throttle-tsx.png
throttle-tsx.png (30.88 KiB) Viewed 156 times
All throttle bodies have two components - a DC motor to position the throttle plate, and a throttle position sensor to determine where the throttle plate is. The throttle position sensor has two resistive elements (A & B) for multiple redundancy. The motor is driven both open and closed by the ECU or controller, switching voltage across the motor using two sets of transistors.
Tests - Throttle Position Sensors
1. TPS A & B voltage
A. Civic Si
Closed 0.60 / 1.48 volts
Default position 0.85 / 1.67 volts
Open 4.00 / 4.20 volts
B. TL-S
Closed 0.62 / 1.50 volts
Default position 0.89 / 1.72 volts
Open 3.85 / 4.07 volts
C. ZDX
Closed 0.60 / 1.47 volts
Default position 0.90 / 1.72 volts
Open 3.97 / 4.17 volts
2. Throttle plate position
A. Civic Si
Closed 0.1%
Default position 7.8%
Open 105%
B. TL-S
Closed 0.0%
Default position 9.1%
Open 100.3%
C. ZDX
Closed 0.1%
Default position 9.5%
Open 102.6%
The TPS sensor for each throttle body works in the same way. The default position is different for the TL & ZDX throttle bodies.
Tests - Motor
1. Motor resistance
Averaged over 6 measurements, open direction and closed direction, using actual current for set voltage
A. Civic Si 2.85 ohms
B. TL-S 1.70 ohms
C. ZDX 1.35 ohms
2. Peak current @ 14V
A. Civic Si 4.9 amps
B. TL-S 8.2 amps
C. ZDX 10.4 amps
As the throttle body gets larger, the motors are higher torque / higher current. This is not proportionate to the throttle body opening area, as the ZDX throttle draws almost twice the current of the Civic throttle body.
Under real world conditions the throttle controller will vary the current to the motor in order to position the throttle plate. The current required to do this will be around the same for each throttle body (roughly 1 amp). However, the peak current is much higher on the larger throttle bodies. This is likely to be a problem if the transistors in the throttle controller shut down from over current or over temperature.
With the Civic Si / R18 ECU, the throttle controller uses a IC chip to drive the throttle body motor. The IC is rated at 5.0 amps continuous current, and has over current and over temperature shut downs. Switching to a throttle body which uses more than double the current is likely to overload the controlling IC.
Conclusion
Bigger throttle bodies draw more current, potentially overheating the controlling circuitry, causing erratic throttle operation and errors. This cannot be fixed by software.