Flowbench Testing

Here at Race Developments, we use the latest in computerised flowbench technology to develop your engines breathing ability.  Everything from the cylinder head, to the induction system and exhaust system can be tested for efficiency and throughput.

By making small adjustments and then testing on the flowbench, changes can be proved/disproved and recorded without any human error in the input process.  All results are stored on computer and can be analysed afterwards.  Predictions can be made for the effect of changing engine specs on power and torque output.

Below is a graph showing the improvements made to a standard cylinder head with some stage 2 porting.  It shows flow capacity in litres per second on the y-axis and valve lift in mm on the x-axis.

The lower blue line is the original intake flow and the upper blue is the modified one.  Likewise, the green is the original exhaust flow and the red the modified one.  You can see quite clearly that flow has been improved throughout the lift range which is the key to porting a head.  It would be easy to just grind much bigger ports, but without careful attention to what the flowbench reads, the mid-range for example could have a massive hole in it.

      

In addition to recording the volume of air flowing through the ports, the flowbench can measure air velocity.  This is measured with a pitot tube as shown below at various different points around each port.  Again, this is all recorded by the computer so there are no errors with data entry.

The pictures below show the port velocities for both the standard and modified heads shown in the graph further up the page.  Each port shown here has had velocity readings taken for 9 different points in the port at 2 different lifts.  The upper 4 maps are the standard head and the lower for the modified head.  The key in the middle shows air velocity in metres per second.

Just as with the airflow graph further up the page, it is quite clear that air velocity has been improved dramatically.  Note that the exhaust port velocities are higher at 5mm of lift on the ported head than they are at 10mm of lift on the standard one.  This bike engine has tremendous midrange as well as a much improved top end and really punches out of the corners as a result.

It is the careful balance of all these factors which is key to producing a good power delivery.  Before modifying a head, we will find out the intended application, engine and cam specs and what you want from the engine.  The head is then built around this.  We do not sell "off the shelf" headwork, because every application and engine are different.  As a result, each head is worked on as though we have never seen that model before.

See the cylinder head page for further information.