Hi I have a question I can't seem to find a straight answer anywhere, sometime later this year I plan to get a 20g billet turbo, but I can't decide if I want a 6 blade or 7 blade wheel, I know that the 6 blade can suck in more air and doesn't have to spin as fast and push as much boost as a 7 blade wheel does because more space in between the blades and stuff, but what about the 7 blade, I know they both have upsides and downsides when compared with each other but which is better, and also which sounds better, for dosing and stuff

 

I've been building turbos for about 2 years now and this is what I theorized, so I don't have any research data to back it up. The 6 blade is lighter than the 7 blade, so it will spool up faster from less mass. The 7 blade moves more air per revolution, so it will flow more air than 6 blade at any revolution. The point where 6 blade will have advantage is when the turbine wheel energy can no longer spin the 7 blade compressor wheel any faster. So there isn't a simple answer since the compressor wheel is only half of the equation.