In our 800 sim there is a slight kick on the rudder as the flaps are retracted and reach the UP mark on the flap gauge. I offer info from my airline’s training department below and assume the real aircraft also has this kick. Will keep looking for more info. Is there someone out there who has flown real a aircraft engine out clean up during testing that can confirm?
“A number of reports have been received regarding the different flight characteristics observed when flying the 737-800 simulator. The discussion centers on the different amount of rudder pedal input required when maintaining a constant track. This at times requires full rudder input accompanied by some aileron. In short, the 737-800 simulator is performing as per the aircraft. The objective data has been confirmed as correct along with subjective assessment also confirming that the simulator reflects the aircraft. It is important to not just convey but to emphasize the difference between the 737-300/400 and the 737-800 aircraft during training. The difference in flight characteristics is mainly due to the Rudder Pressure Reducer in the 737-800 compared with the 737-300/400. When an engine fails on the 737-300/400 the full 3000 p.s.i. is being delivered to the rudder PCU whereas the 737-800 reduces hydraulic pressure to the PCU when the aircraft passes above 135 knots. In essence the 'blow back' effect on the rudder surface deflection is greater on the B737-800 and results in less rudder surface deflection compared with the 737-300/400. To the pilot the result is more rudder input is required under identical flight conditions. The 'blow back’ effect will be exacerbated if over controlling and sideslip occurs, sideslip will further reduce rudder surface deflection and if rudder pedal input has reached it's maximum more aileron may be required to retain the required tracking. Only very specific and rarely encountered conditions require aileron input. Less than ideal pilot performance may also require the use of aileron in addition to full rudder input. The requirement for aileron is more likely where the departure procedure requires an immediate turn after take-off. The 'spongy' feedback through the rudder pedal is simply replicating cable stretch. This is a new experience if full rudder pedal displacement has not been experienced. This issue could impact the training value to pilots if the different characteristics are dismissed as being a result of poor fidelity rather than a true reflection of the aircraft performance. If the crew believe it to be an inaccurate reflection of the aircraft it downgrades the effectiveness of the training too generally and fails to prepare the pilots for the reality of the aircraft. “