Turbo Manifold Dimensions

Exhaust manifold dimensions has a significant impact on engine characteristics especially for turbo charged engines.

The below table provides a base line for exhaust manifold dimensions for turbo charged engines.

Note: Use smaller diameter tubes for widest power band and larger size where top-end power is more important and sluggish throtttle response is acceptable.

Engine Type Engine Configuration Exhaust Tube Diameter (inches)
4 Cylinder
Single Turbo
1300cc 1.25-1.5
1600cc 1.25-1.625
2000cc 1.375-1.75
2200cc 1.375-1.75
2400cc 1.5-1.875
6 Cylinder
Single Turbo
2000cc 1.125-1.5
2300cc 1.25-1.5
2500cc 1.25-1.625
6 Cylinder
Twin Turbo
2600cc 1.25-1.625
3000cc 1.375-1.75
3500cc 1.5-1.75
4000cc 1.625-1.75
8 Cylinder
Twin Turbo
4000cc 1.375-1.62
5000cc 1.5-1.625
5700cc 1.5-1.75
7000cc 1.75-2.125
8200cc 1.875-2.375