Multiair's head has too small ports according to FIAT's policy. Manufacturer's strategy for maximum driveability, maximum percentage of torgue in lowest rpm and lowest amounts of pollutants are the main reasons. Small ports provide high velocity of incoming mixture in low rpm, but also decrease dramaticaly the maximum flow capactiy. As a result, engine can't be supplied with enough amount of a/f mixture when power demands are icreased too much.
Our efford is to port the head in a way that maximum flow capacity is increased providing gains in high rpm ,while low rpm torgue is least effected.
Why is important to combine camsfaft upgrade with head porting?
According to our analysis multiair's valve opening cachacteristics are insufficient for big power demands and high revving. So, porting the head and increasing flow rate while the new amount of mixture dont have enough time to enter the combustion chamber before valve close again gives minimum gains. Porting could be done with any setup, but porting in way perfectly combined with upgraded camshaft would give maximum gains.
As we have promised, not only we validate our claims providing our supporters with data of our developments, but also we are proving why tuning means to improve everything in perfect combination.
Here is the flow charts of a stock head vs a ported head. Pay attention how ported head not only increases the flow at a huge percentage, but keep increasing it as valve lift increases before it becomes constant. That means flow increases at also low and mid valve lifts. In order to take full advantage of that flow we need to redesign the cam profile. That's why we say that an upgraded camshaft combined with ported head give maximum gains.