Compressor wheel setups - compound turbos

mike diesel

mike diesel

New member
Joined
Aug 7, 2012
Messages
431
Built the motor in my dmax a few weeks back and am now getting my compound turbos going. I will be building the kit myself utilizing my current s472/87/1.0 as the primary charger and adding my turbonetics hybrid y2k 88mm over it for the atmo. The y2k essentially has a gt55 turbine in it with a 1.23 ar housing, ball bearing and HPC billet 6 blade compressor. My s472 is setup with a billet 11 blade compressor.

I am curious as to how much of a difference the blade count in the primary has on overall performance? Seems 72mm billet compressors are far and few between to find that people have in stock on the shelve. I did some searching and finally found this 11 blade wheel that I didn't have to wait a few weeks for. I initially wanted a 6 blade wheel..

I thought I read 11 blade compressors rock on their own but aren't the best in the primary when in a set of compounds. Would it be worth my time to source out a billet 6 blade wheel to swap for the 11 blade wheel?

Truck is daily driven, drag truck, fun toy... goal is to make 1000hp on fuel and maybe touch 1100 if i get crazy. Is swapping compressors worth my time?
 
Last edited:
Sorry I don't have a good answer for your question, but just fyi, "primary" refers to the atmosphere turbo. The high pressure turbo is the secondary.
 
Frankly it seems like the best results yield from a first stage that can still hit the high PR's. Use the big wheel's to your advantage.
 
Joesixpack said:
Frankly it seems like the best results yield from a first stage that can still hit the high PR's. Use the big wheel's to your advantage.
Click to expand...

I'm not sure i understand what you are saying. I don't plan on changing compressor size but simply changing blade count (6 blade, 7 blade, 11 blade).. I was curious if changing blade count from 11 blade down to a 6 blade 72mm wheel would benefit me in anyways. I have read that 11 blade wheels are great on their own but don't respond well when they are being force fed by another charger.

I'm just wondering if this would at all be worth my time or if i should forget about it and run what i have.
 
I mean, saying 11 blade is like saying white truck. There is just so much more to compressor wheel performance than blade count.

If you have it, run it. Maybe test a different wheel once you get it running but how could you ever know that it's going to be worth the price to switch ahead of time?
 
I think what Joesixpack was saying is that you already have a large inducer high pressure turbo so using an 11 blade compressor that is more effective at higher pressure ratios could in fact be a benefit in your combo. You should be able to push that turbo high into the map without moving into the choke line.
 
When you get the big one singing you bypass small one almost completely so blade count doesnt matter.
 
Leiffi said:
When you get the big one singing you bypass small one almost completely so blade count doesnt matter.
Click to expand...

No you dont, that's why they are called compounds. The secondary compounds the primary's boost.
 
exactly, compound; both always flowing air, small adding pressure to flow of larger. Sequential: smaller gets bypassed as larger flows.


I believe the general rule of thumb is that the higher the blade count (11 etc) the higher PR it will efficiently handle, while lower blade count will generally flow more air at lower PR. Of coarse this is all else being the same.
 
Well i have no complaints with the 11 blade wheel in my s472. And seeing how I can't readily find a 6 blade wheel that isn't $500+...I'll just leave it alone.
 
You must log in or register to reply here.
Back
Top