This is awesome work. But it should be 95% overall, because each wastegate increases that much (2x20 to 2x28mm).
I messed around a bit with ChatGPT. Obviously there are a lot of guesstimates (for example, I have no idea if our wastegates really pass 15-30% of total exhaust flow at high rpm) so take it with a
huge grain of salt, but here's what I got after feeding it details on the Stinger engine, torque & power curves, and asking it to compare to measured flow rates on similar engines. I also asked about stuffed turbos at 600hp.
But keep in mind it's just taking peak horsepower, approximating total flow, estimating what portion goes through the wastegate, and then how much the bigger WG will increase flow. Relieving backpressure on the turbine should also improve its efficiency, but ChatGPT said it couldn't directly calculate that, and only provided a further 5-10% power gain as a guideline. Those values are even bigger than the flow-based ones, and are in parentheses in the last two columns:
View attachment 89264
| Engine Setup | Wastegate Diameter | Area Increase | WG Flow Increase | WG % Flow | Engine Flow Increase | Total Engine Flow (CFM) | Total Flow Incr (CFM) | Horsepower Gain (Low Estimate) | Horsepower Gain (High Estimate) |
|---|
| Stock Engine (368 hp) | 26mm | +69% | +48% to +62% | +15% to +30% | +7.2% to +18.6% | 530 CFM | +22.8 to +32.3 CFM | +11-18 hp (+18-37 hp) | +15-24 hp (+18-37 hp) |
| Stock Engine (368 hp) | 28mm | +96% | +67% to +86% | +15% to +30% | +10.1% to +25.8% | 530 CFM | +35.6 to +45.5 CFM | +15-24 hp (+22-37 hp) | +21-32 hp (+22-37 hp) |
| Tuned Engine (485 hp) | 26mm | +69% | +48% to +62% | +15% to +30% | +7.2% to +18.6% | 698.4 CFM | +30.0 to +42.5 CFM | +15-24 hp (+24-48 hp) | +21-32 hp (+24-48 hp) |
| Tuned Engine (485 hp) | 28mm | +96% | +67% to +86% | +15% to +30% | +10.1% to +25.8% | 698.4 CFM | +46.9 to +60.0 CFM | +21-32 hp (+29-54 hp) | +29-43 hp (+29-54 hp) |
| Stuffed Turbos (600 hp) | 26mm | +69% | +48% to +62% | +15% to +30% | +7.2% to +18.6% | 864 CFM | +37.2 to +52.6 CFM | +18-28 hp (+30-60 hp) | +25-38 hp (+30-60 hp) |
| Stuffed Turbos (600 hp) | 28mm | +96% | +67% to +86% | +15% to +30% | +10.1% to +25.8% | 864 CFM | +58.0 to +74.4 CFM | +25-38 hp (+35-60 hp) | +34-50 hp (+35-60 hp) |
