Debating Turbocharging?

[XR8tt]

http://s4.photobucket.com/albums/y146/EBXR8240/?action=view&current=eaton_diagram2.jpg

 

[cribbj]

Although the rotors are twisted, that doesn't make it a screw supercharger. Here is a quote from Eaton's supercharger homepage: http://www.eaton.com/EatonCom/Marke...chargersCylinderHeads/Superchargers/index.htm

SUPERCHARGERS

Eaton manufactures highly engineered, roots-type positive displacement superchargers. The Eaton supercharger increases torque across the entire operating range without compromising drivability or emissions.


And their FAQ page: http://www.eatonperformance.com/superchargers/sc_FAQ.html

The roots supercharger has been around for a long time, how is the Eaton supercharger different? The Eaton supercharger is essentially a Roots blower pump, with one substantial design wrinkle; each rotor has been twisted 60 degrees to form a helix. The two counter rotating rotors have three lobes, which intermesh during operation. These twisted rotors, along with specially designed inlet and outlet port geometry, help to reduce pressure variations resulting in a smooth discharge of air and a low level of noise during operation. This arrangement also improves efficiency over traditional Roots superchargers. With helical rotors and an axial inlet the Eaton supercharger can be spun to up to 14,000 rpm, thereby reducing package size.

So until Eaton decide to start dabbling in screw technology it's pretty safe to say that if you have an Eaton supercharger, you have a Roots type blower.

Here is a photo of the lobes from a classic Roots compressor, then the twisted lobes from the Eaton, and the third pic is of the screws out of a Lysholm. All photos courtesy of Wiki and Eaton:

 

[XR8tt]

Exactly it says Roots style...
Now check Whipple they are very similar !!...
The original Roots design is in top pic where there's only two vanes per rotor...
http://www.whipplesuperchargers.com/product.asp?ProdID=1162
Looks like twin screw to me....
Yes the bottom two are much the same...

 

[cribbj]

Not sure what you're driving at XR8TT, but to say the Eaton is a screw compressor because it has twisted rotors, and looks a bit like a screw isn't correct. That first illustration in my post below was just the "classic" Roots from a century ago, and has little or nothing to do with present day Roots technology. Eaton define all their compressors as Roots

Whipple are a packager for Lysholm, who are owned by Opcon Autorotor, and their compressors are screws.

Kenne Bell are a packager for Opcon-Autorotor, and their compressors are screws.

 

[rms]

A 'Roots' blower, whether straight or twisted rotors, has no internal compression of the air.
A 'screw' blower has internal compression of the air within the rotors.

 

[XR8tt]

I thought the Whipple was more like two augers transferring air?? That's why they often have outlets at the end of compressor or housing....
By them saying Roots type ? Is that them saying its not a centrifugal type ??? The two possitive displacement blowers have become very similar...

 

[canman44]

A 'Roots' blower, whether straight or twisted rotors, has no internal compression of the air.
A 'screw' blower has internal compression of the air within the rotors.

Exactly. The screw type compresses the air in between the veins of the screws. the roots i believe, as in this may not be correct, takes a chunk of air and transfers it to the other side of the supercharge case. the rotation of the rotors transfers enough air to where it compresses it so that it can fit all the air molecules in there. basically, i think it puts more air in than can fit, this in turn compresses the air mass to accommodate for the excess.

So does anyone know of a good write on a supercharged 1uzfe? I've been reading threads, but a write up would help a lot just to have things more organized.

 

[XR8tt]

This explains somewhat... Though obviously biased a little....
http://www.kennebell.net/techinfo/general-info/twinscrew-vs-roots-fromcatalog.pdf

 

[canman44]

Thanks XR8tt thats clears up the operation of the two styles a little better. As you mentioned this is probably a somewhat biased research. There has to be some kind of truth to it. Are there any screw type superchargers that will fit the 1uzfe?

 

[Lextreme II]

While twin screw is an awesome choice. I drool over one few days ago. I think its was PWD and Cribbj. M90 is the most affordable root charger and M112 will take little more $$$. If money is NOT an issue. Twin is the way to go.

Centrifugal is in between Root and Turbo.... So its all depends on your budget and application.