RS660 Lap Time Simulator: 7-Second Gain at Spreewaldring

STC Spreewaldring September practice RS660 2026

Aprilia RS660, Track Days, Racing Line Optimization, Lap Time Simulation

Since the beginning of summer, I have been working on the motorcycle Lap Time Simulator. To validate the simulator's results, I went to my home track for a practice ride. The plan was to follow the simulator's recommendations and compare them with the real results.

A secondary goal was to build confidence on the track and to keep practicing my sense of speed and feel for the corner-entry limits. Since my observation was at Lausitzring, I kept practicing a “no display” approach, with the dash showing only a selected gear and the traction control intervention LED bar.

As a result of the practice track day, I became at least 7 seconds faster without chasing time by using an aggressive throttle strategy and focusing on the racing line and body position.

Summary

Lap Time Simulator clearly suggested corners and segments where I could easily cut the lap time
(7 seconds already gained)
Based on the previously collected data, I identified that I could use at least 20% more of the brakes (the motorcycle can deliver at least -1.1 G in vertical orientation)
I got more confident riding at a high lean angle; however, the slow roll rate limits my speed in the chicanes and curvy segments of the track
My upper-body position caused the motorcycle to lean at a higher angle (53 degrees on the road tire), increasing the risk of an accident

Key findings

Simulator input

To obtain reliable reference data, I ran several sessions on the track to record the “available grip” by measuring the peak braking deceleration, the transition grip at corner exit, and the comfortable peak of my cornering ability on the road tire.

After proper tire warm-up (60- 65 °C), I managed to achieve the following values:

Peak deceleration with rear wheel lift: -1.05 G
Maximum lean angle: 53 degrees (GPS calculated, IMU corrected)

Using real-world condition values, a given motorcycle specification, and the track layout, I simulated the achievable lap time based on my driving abilities and the motorcycle's limits.

Simulator output

Without introducing additional risks, the simulator estimated that, given my braking abilities, peak lean angles, and ability to flick the motorcycle through chicanes (as recorded by chassis roll rate), my best possible lap time is 1:29.190. In contrast, my personal best at this track is 1:53.057.

The dashed blue line is the real recorded GPS data at 25 Hz.

The solid green line is the racing line optimized for the RS660, my abilities, and my weight.

To be more efficient, I ranked microsegments by potential time gain.
Improving in these segments can give me the most effective strategy for a faster lap.

Best lap attempt

To improve the lap time, I decided to focus on the segments with the greatest potential for improvement.

Corner 10* (Omega) - Chain of three right-hand corners - Theoretical gain: -3.86s
Corner 7* - Long left-hand corner - Theoretical gain: -2.80s
Corner 5* - Right-hand corner with increasing radius - Theoretical gain: -2.73s

I ignored the slow left-hand corner (9*) to reduce risk.

Corner numbering * is automatically assigned based on the trajectory line and does not align with official track corner numbers.

As a result, I achieved a lap time of 1:45.950 (−7.1 s). As shown in the plot below, I improved speed through the planned corners, and some of those gains carried over to the following straight segments. In this session, I was more confident on the throttle and made significant gains in braking.

Based on these clear suggestions for improvement and my achievements, I will continue investing time in Lap Time Simulator development and validation. After consulting my racing network and considering the simulation's nature, the suggested 1:29.190 is not unrealistic; however, the simulation does not account for real-world track surface conditions, so it is unsafe to chase on road tires.