what kind of boost pressure can tuners get if the engine compression ratio is around 10:1?

The boost pressure that tuners can achieve with an engine having a compression ratio of around 10:1 can vary based on several factors, including fuel type, tuning, engine design, and the specific goals of the build. However, there are some general guidelines: 1. **Fuel Type**: Higher octane fuels can tolerate more boost without knocking. For example, using premium fuels like E85 or racing fuels allows for higher boost pressures due to their higher resistance to detonation. 2. **Engine Design**: The design of the engine, including things like valve timing, intercooling, and the quality of materials used, can impact how much boost can be reliably run. 3. **General Guidelines**: - With pump gasoline (91-93 octane), a common range for a 10:1 compression engine might be around **6-10 psi** of boost. - If using higher-octane fuels like E85 (which has a higher ethanol content), tuners may safely push boost levels as high as **12-20 psi** or more, depending on other tuning parameters and engine components. 4. **Supporting Modifications**: The ability to run higher boost levels often requires supporting modifications, including upgraded fuel systems, better intercooling, and improved exhaust systems, among others. It's crucial for those tuning their engines to monitor A/F ratios, knock, and other parameters to ensure engine safety and reliability when increasing boost. Always consult with a professional tuner for your specific application to find the optimal settings for your vehicle.