1. T3, T4, T5, etc.: These are size designations used by turbocharger manufacturers to indicate the general size and flow capacity of the turbocharger. The higher the number, the larger the turbocharger and the more air it can flow.
2. The T series designations are commonly used by Garrett, a well-known turbocharger manufacturer. Other manufacturers may use different designations, such as TD04, TD05, etc.
3. The T3, T4, T5 designations are based on the size of the turbine wheel. The larger the turbine wheel, the more exhaust gas it can handle, which in turn determines the amount of air the turbocharger can compress.
4. T3, T4, T5 also indicate the flange size and bolt pattern of the turbocharger housing. This is important for compatibility with the exhaust manifold and downpipe.
5. Other letters and numbers may be used in turbocharger designations to indicate specific features or variants, such as "A/R" (area-to-radius ratio of the turbine housing), "WG" (wastegate), "VNT" (variable nozzle turbine), etc.
Understanding the size and specifications of a turbocharger is important when selecting and installing one for a particular engine application. It ensures that the turbocharger is appropriately matched to the engine's requirements in terms of airflow and boost pressure.
