Generally, an 11 blade will out flow a 6+6 at the top end, while a 6+6 will spool faster and have less chance of surge. Depends on a lot of other factors though like blade geometry, angle, height, and tip length. All else equal, an 11 blade has more total blade area and more space between each blade. Each blade is acting on more air, but in a larger space and for slightly longer. At very high RPM it is stuffing more air into the compressor per rotation with less in the way, but at lower RPM it is fighting larger pressure waves with the same exhaust pressure. That's my approximate understanding. Again though it really matters the exact design of any wheel. Other factors like nose diameter, root thickness, blade thickness, and overall weight matter too. That's why I said all else equal, though generally blade designs will be a bit different between full blade and splitter wheels other than just the half blade heights.
@@V8Lenny That depends on blade height and angle as well as thickness, like I mentioned. Look at compressor maps and dyno graphs of 11 blade vs 6+6 blade. The 6+6 will generally be more efficient at lower pressure ratios and power levels while the 11 blade will have a taller map with efficiency higher in the power spectrum. The root AKA exducer side of the compressor is more important overall for power output than the inducer. The size of the inlet orifice creates an overall restriction and power limit, but is far from the main determining factor in power band. The suction at the tip of the inducer blades is determined by the overall ability of the wheel to flow and compress air, so the amount of area the blade tips take up is less important than the ability of the blades to move air. Again, general rules not perfect and complete explanations.
@@802Garage depends if you need high presssure ratio or high flow. But I dont see full blades in tractor pulling. Or anywhere else except Garrett OEM applications that are used because they are quieter. Aftermarket gets those Garrett industrial wheels because they dont care much about racing.
Splitter wheels are always an even number to maintain balance. There has to be an equal number of tall and short blades. 5+5, 6+6, and 7+7 are most common. There are even and odd number full blade wheels though with 8 to 13 being most common.
Full blade is for wider power band but less flow.
Generally, an 11 blade will out flow a 6+6 at the top end, while a 6+6 will spool faster and have less chance of surge. Depends on a lot of other factors though like blade geometry, angle, height, and tip length. All else equal, an 11 blade has more total blade area and more space between each blade. Each blade is acting on more air, but in a larger space and for slightly longer. At very high RPM it is stuffing more air into the compressor per rotation with less in the way, but at lower RPM it is fighting larger pressure waves with the same exhaust pressure. That's my approximate understanding. Again though it really matters the exact design of any wheel. Other factors like nose diameter, root thickness, blade thickness, and overall weight matter too. That's why I said all else equal, though generally blade designs will be a bit different between full blade and splitter wheels other than just the half blade heights.
@@802Garage full blade flows less because blades are blocking intake, thats why split blade was found about 50 years ago.
@@V8Lenny That depends on blade height and angle as well as thickness, like I mentioned. Look at compressor maps and dyno graphs of 11 blade vs 6+6 blade. The 6+6 will generally be more efficient at lower pressure ratios and power levels while the 11 blade will have a taller map with efficiency higher in the power spectrum. The root AKA exducer side of the compressor is more important overall for power output than the inducer. The size of the inlet orifice creates an overall restriction and power limit, but is far from the main determining factor in power band. The suction at the tip of the inducer blades is determined by the overall ability of the wheel to flow and compress air, so the amount of area the blade tips take up is less important than the ability of the blades to move air. Again, general rules not perfect and complete explanations.
@@802Garage depends if you need high presssure ratio or high flow. But I dont see full blades in tractor pulling. Or anywhere else except Garrett OEM applications that are used because they are quieter. Aftermarket gets those Garrett industrial wheels because they dont care much about racing.
Is there a 11 blade that is a split wheel?
Splitter wheels are always an even number to maintain balance. There has to be an equal number of tall and short blades. 5+5, 6+6, and 7+7 are most common. There are even and odd number full blade wheels though with 8 to 13 being most common.