8 hours ago
Some before and after shots.
Here is some more RB head porting we have finished for one of our customers in Melbourne.
Now with any port job we do, we like to find out exactly what the combo has. This helps us understand what port in needed and what the limiting factors are. This setup was running a Greedy intake seeing around 900rwhp, but from our past experiences I knew we would need the intake as these have quite the restriction in them, if you look at the pictures you can see an inch or so into the intake the CSA gets very tight.
Now if we take a quick look at the math on the mapped CSA we will see a problem straight away. The window area in the port and intake is around 1500mm squared. But if we measure an inch or so back up the runner we find it's bearly 1100mm squared. So that's around a 36% reduction in CSA.
So this massive reduction in CSA mid runner will create a massive spike in velocity locally. Then a massive slowing again as it the CSA grows again. This speed up slow down speed up again can and will negate most of the hard work done improving head flow by porting it. So clearly something had to be done to improve to create a steady velocity gradient to the valve as our goal is to improve HP per PSI.
#bainracing #portedbybain #rb30 #rb25 #rb26 #r33skyline #r32gtst #r23gtr #boosted #skyline