Throttle cut: Difference between revisions

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==Definition==
Throttle cut is any condition which causes the ECU to reduce the throttle pedal angle, even if the actual accelerator pedal potentiometer is at WOT.
Throttle cut is any condition which causes the ECU to reduce the throttle pedal angle, even if the actual accelerator pedal potentiometer is at WOT.


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;Boost deviation: Actual boost pressure far exceeds desired boost pressure by around 200-230mbar (3-3.3 psi). The ECU will only restore throttle angle once actual boost pressure falls to at or below the desired boost pressure.
;Boost deviation: Actual boost pressure far exceeds desired boost pressure by around 200-230mbar (3-3.3 psi). The ECU will only restore throttle angle once actual boost pressure falls to at or below the desired boost pressure.


==Examples==
[[Throttlecut.csv]] shows a 3rd gear run where the ECU cuts throttle.
[[Throttlecut.csv]] shows a 3rd gear run where the ECU cuts throttle.


{| class="wikitable" style="background:lightgrey"
|+ Throttle cut onset
!TIME||RPM||ThrottlePlateAngle||BoostPressureDesired||BoostPressureActual||Deviation
|-
|497575||4025.75||99.6078431372549||2327.109375||2490.625
|- style="background:green; color:white"
|497645||4046.75||100||2315.1953125||2508.90625||193.7
|- style="background:orange; color:white"
|497716||4114||100||2302.1484375||2503.0859375||200.9
|- style="background:orange; color:white"
|497786||4151.5||99.6078431372549||2271.1328125||2508.2421875||237.1
|- style="background:red; color:white"
|497856||4200.5||45.8823529411765||2263.1640625||2488.203125||225.0
|-
|497926||4230||43.921568627451||2248.3984375||2457.65625
|}


{| class="wikitable" style="background:lightgrey"
|+ Throttle cut recovery
!TIME||RPM||ThrottlePlateAngle||BoostPressureDesired||BoostPressureActual||Deviation
|-
|499748||5183||48.2352941176471||2200.546875||2222.8515625
|- style="background:red; color:white"
|499819||5211||48.2352941176471||2208.0078125||2226.5625||18.6
|- style="background:orange; color:white"
|499889||5246.5||48.2352941176471||2216.2109375||2217.34375||1.1
|- style="background:green; color:white"
|499959||5294.5||77.6470588235294||2220.234375||2194.8046875||-25.4
|-
|500029||5319||100||2227.1875||2166.2109375
|}

Revision as of 22:36, 27 July 2006

Definition

Throttle cut is any condition which causes the ECU to reduce the throttle pedal angle, even if the actual accelerator pedal potentiometer is at WOT.

The two main causes of throttle cut are

ESP activity (a.k.a. traction control)
The ECU senses that one or more wheels are losing traction. It does this if ESP is enabled, the ABS wheel sensors show a large discrepancy in wheel speed.
Boost deviation
Actual boost pressure far exceeds desired boost pressure by around 200-230mbar (3-3.3 psi). The ECU will only restore throttle angle once actual boost pressure falls to at or below the desired boost pressure.

Examples

Throttlecut.csv shows a 3rd gear run where the ECU cuts throttle.


Throttle cut onset
TIME RPM ThrottlePlateAngle BoostPressureDesired BoostPressureActual Deviation
497575 4025.75 99.6078431372549 2327.109375 2490.625
497645 4046.75 100 2315.1953125 2508.90625 193.7
497716 4114 100 2302.1484375 2503.0859375 200.9
497786 4151.5 99.6078431372549 2271.1328125 2508.2421875 237.1
497856 4200.5 45.8823529411765 2263.1640625 2488.203125 225.0
497926 4230 43.921568627451 2248.3984375 2457.65625


Throttle cut recovery
TIME RPM ThrottlePlateAngle BoostPressureDesired BoostPressureActual Deviation
499748 5183 48.2352941176471 2200.546875 2222.8515625
499819 5211 48.2352941176471 2208.0078125 2226.5625 18.6
499889 5246.5 48.2352941176471 2216.2109375 2217.34375 1.1
499959 5294.5 77.6470588235294 2220.234375 2194.8046875 -25.4
500029 5319 100 2227.1875 2166.2109375