How do I choose and configure the correct TPA (Throttle PID Attenuation) curve to reduce oscillations at high throttle during racing?

Question

Start with TPA at 0.65-0.75 and a breakpoint around 1500-1750 to gradually reduce PID authority as throttle increases. Fine-tune by checking BlackBox logs for oscillations during full-throttle punches and adjusting the curve steeper or gentler based on flight behavior.

Answer 1

TPA works by reducing your PID gains as throttle increases because props generate more authority at high RPM, making your tune effectively too aggressive. Without TPA, a quad tuned for smooth hovering becomes a twitchy, oscillating mess when you punch the throttle during a race.

The TPA value represents how much your PIDs are reduced. A TPA of 0.65 means at full throttle your PIDs are reduced to 35% of their base value. Most racing quads need TPA between 0.65 and 0.75. Heavier quads or those with lower KV motors can often run higher values like 0.75-0.80, while lightweight freestyle rigs might need more aggressive reduction around 0.60-0.65.

The breakpoint determines when TPA starts working. Setting it at 1500 means TPA begins reducing PIDs once you exceed 50% throttle. For racing, I typically start at 1650-1750 because you want full PID authority through the middle throttle range where you spend most of your time navigating gates. Only the hard punches need attenuation.

Here's my process: Set TPA to 0.70 and breakpoint to 1650 as a baseline. Record several race runs with BlackBox logging enabled. Review the gyro traces during full throttle sections. If you see high-frequency oscillations appearing above 75% throttle, you need more attenuation so lower the TPA value to 0.65. If the quad feels mushy or unresponsive at high throttle, increase it to 0.75.

You can also adjust the breakpoint. If oscillations start earlier in the throttle range, lower the breakpoint to 1500. If you're losing responsiveness in the mid-range, raise it to 1800. Some pilots run TPA curve instead of linear, which gives a gentler transition. This is the tpa_curve parameter in Betaflight, typically set between 0 (linear) and 0.5 (exponential).

Temperature matters too. Motors heat up during aggressive racing, changing their characteristics. What works on the first pack might oscillate by pack three. I usually tune slightly conservative, then if the quad feels too soft after heating up, I'll increase breakpoint by 50-100 points between heats.

Don't copy someone else's TPA settings blindly. A 5-inch quad on 2450KV motors needs completely different values than a 5-inch on 1750KV. Your specific motor-prop combination, all-up weight, and PID tune determine the right TPA curve.