compressor wheel design

[Ppayer38]

So I've been checking out different turbos and I see a lot of different compressor wheel designs... Some are a dual 6 blade and some are 10-11 blade. Some are all tall blade and some have secondary shorter blades. I'm sure each design is made to work within a certain pressure area and boost level be it low or high... But which is better for what and why is it better? I'm looking for theory and aerodynamkc chat here that explains these better!

What is considered high boost, how do you figure out your pressure ratio, and thing like this...

I understand the inducer/exducer part of wheel designs as far as what increasing/decreasing size of each does and matching the compressor to the turbine wheel for the best efficacy. I've also contacted a few turbo companies and they were no help in explaining why there wheels are the way they are or even the design of them in general... I've read many write ups and documents just nothing specific.

[Bud92gsx]

Subscribed.

[JusMX141]

Everything I've learned up until now has proven that alternating large/small blades is better for moving air at high boost levels, and equal-sized blades (think 14B, 17C) are more efficient at lower boost levels.

Then the Garrett GTX series comes along, and that theory goes out the window.

[ExtremeTurboSystems]

I am sorry...i could not resist...

[Bud92gsx]

But then couple your x wheel with the desired turbine wheel.

But then wait, does this apply to VGT or no..I will assume no.

And I'm going to google the ATX design.

[Ppayer38]

Originally Posted by JusMX141

Everything I've learned up until now has proven that alternating large/small blades is better for moving air at high boost levels, and equal-sized blades (think 14B, 17C) are more efficient at lower boost levels.

Then the Garrett GTX series comes along, and that theory goes out the window.

I very much agree with this! And thats is why I was looking for a little more info on the subject haha. Also what is consider high boost and what is considered low boost?

The gateway stuff says they perform better @ x.xx pressure ratio because they can scoop more air even under lower or the same boost or atleast that's what they told me and what I've seen as far as dyno results.

[knochgoon24]

Best way to look for a trend would be to start looking at compressor maps.

Every company has their own theory behind what they design. So don't be surprised to see two different designs preform similar.