Overspinning SI trim?

[97stanger]

I just got my car back last night from my tuner. Basically, the car pulls great up to 6000, than after 6000 it pulls to 6400 with no power gains. Uncorrected the car is making 510/460. I'm seeing 17.3 psi out of this SI trim. My cam is a custom grind bullet racing 220/230, 533/571, 114 lsa. My heads are MMR stage 3 PI heads. My intake is eddie vic jr with 6061 plenum. I'm going with a triple disc converter over the winter to hold this power better, but my tuner feels that my blower is whats holding me back at this point. Anybody have any thoughts? I just havent read/heard of many people maxing SI blowers out at low 500's. When I put my 10% overdrive crank pulley, 2.95 blower pulley and 6000 rpms in the calculator, I'm spinning it 53000 and its rated to 52000...just looking for some input. Thanks guys

 

[mikey94gt]

It very well could be... I have a V1 S trim spun to the max, and have also ran into a wall, as the impeller can only flow so much air before it starts to fall off its efficiency map, much like pushing a turbo too hard. in fact, there are efficiency maps for centrifugal blowers just like the ones made for turbos. When the blower or turbo is pushed too hard, it wont flow as much air as it did at slower speeds/less load, and may start to surge and cavitate the blades, possibly breaking them.