7 blade billet vs 11 blade

The intent of the aftermarket 11 blade is to mimic the Garrett GTX design which flows better at high pressure ratio, perfect for sled pulling. They claim somewhere around ~10% better flow.

However, you never know if these companies are full of hot air. (hur hur)
 
I hear Ya. Just Wounder if anyone new the differences between the 7 and 11 besides the obvious of blade count and angle.
 
I'm dumb when it comes to chargers but I'd like to see some testing done. Take the same charger and just change the wheel. Seems to me the more blades there is the more air it would move. Kinda of like a turbine engine.
 
1stack said:
I'm dumb when it comes to chargers but I'd like to see some testing done. Take the same charger and just change the wheel. Seems to me the more blades there is the more air it would move. Kinda of like a turbine engine.
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Think about that, each blade takes up space. The more blades the less air. The more blades though the more efficient at higher pressure. Now a 7 blade is actually a 14 blade. Just with 7 blades at half length (roughly). This is done to try to get the mass air of a lower blade count but the efficiency of a higher count. After talking about my options with Chris at Midwest turbo I decided on an 11blade. Seems to be that sweet spot and works very well. It's also a billet 80mm gt wheel going into an he551v if anyone was wondering.
 
I guess my thought was a 14 blade wheel will take 14 chops of air. Where a 7 blade will only take 7 chops of air. Thus more blades moves more air.
 
I seem to recall dyno sheets from a member on here with direct comparisons (may have been as the atmos charger in a twin config, but direct results none the less). 11 blade would build boost sooner and the 7 blade won on top. If that was the case, 7 blade for a sled puller.
 
GOT-Torque said:
I seem to recall dyno sheets from a member on here with direct comparisons (may have been as the atmos charger in a twin config, but direct results none the less). 11 blade would build boost sooner and the 7 blade won on top. If that was the case, 7 blade for a sled puller.
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If you're talking about Mark Broviak and his Duramax that was a ball bearing cartridge vs. journal bearing as well. I also recall the 11-blade winning everywhere but i'm not certain about that. Hopefully 94 12valve will chime in he ran an 11 blade 80mm s400 in sled pulling.
 
GOT-Torque said:
I seem to recall dyno sheets from a member on here with direct comparisons (may have been as the atmos charger in a twin config, but direct results none the less). 11 blade would build boost sooner and the 7 blade won on top. If that was the case, 7 blade for a sled puller.
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NickTF said:
If you're talking about Mark Broviak and his Duramax that was a ball bearing cartridge vs. journal bearing as well. I also recall the 11-blade winning everywhere but i'm not certain about that. Hopefully 94 12valve will chime in he ran an 11 blade 80mm s400 in sled pulling.
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Whoops, post was pre coffee:doh:

In any event here is the thread you were referencing. Keep in mind this is still pre coffee but I believe the tester suggested they ran out of fuel hence the hit on top but I honestly need to go over it again.

GT4202 versus GTX4202R as primary dyno results - Competition Diesel.Com - Bringing The BEST Together
 
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I ran the 11 blade s480 last year and was very happy with how it ran vs the 6 blade I had before ( same turbine and housing on both).The 11 blade felt stronger on the mid portion of the track and made an extra 3 psi than the 6 blade .

This year I'm running a clipped 7 blade 80 down to 2.6 so I can't compair the two. If you are running a bushed s475 or unbushed I would go with the 11 blade wheel ... if your going to get the wheel clipped the 7 blade will be your best bet.
 
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