Flow Number Comparison between SuperFlow SF-600 and SuperFlow SF-1020 Flow Benches

Cylinder head flow numbers are always of interest to the high performance enthusiast, but it is sometimes difficult to compare numbers from different flow benches because there may be differences depending on brand, installation, calibration, etc. We had a set of Blue Thunder High Riser heads that were max effort ported, and gave the best wedge numbers we had ever seen on R&R Performance's SuperFlow 600 flow bench. We wondered how those numbers would look on a different bench, so we sent them to Barry Rabotnick at Survival Motorsports to have them checked on ET Performance's SuperFlow 1020 bench for comparison.

The charts to the right show the comparison data. This is most valid on the intake side, because at R&R the exhaust ports were flowed with a 2 1/8" pipe on the port, while no pipe was present at ET Performance. Average under the curve on the intake side appears to be about the same for both flow benches, although the SF-600 reads higher at higher flow numbers, and lower at lower flow numbers, than the SF-1020. Nevertheless, the numbers are certainly close, indicating that a properly calibrated flow bench should be repeatable within a reasonable error percentage.

Blue Thunder High Riser Intake Flow Numbers

Blue Thunder High Riser Exhaust Flow Numbers