can anyone explain what the difference between a ball bearing turbo and a rollerbearing turbo is,,

gully

they are the same iirc..

you can also get sleeve bearing turbos.

David

There was a recent thread on NASIOC about this and when I said they were the same I was corrected, but then someone else said they were the same and there were pictures. One said that only the VF34 was a ball bearing, the other VFs were roller bearing, that Garretts are ball bearing. Not sure it makes a huge difference? After all the TD05 is sleeve bearing and spools up better than most/all and flows more than most if not all of the VFs used on Subarus, although not seen any maps for the VF34.

Roller bearings use needle rollers.

Ball bearings have spherical balls (oddly enough).

I'm not convinced roller bearings are all that great, i can't really see that the viscous drag will be any less than a sleeve bearing (which runs on high pressure oil film anyway).

Ball bearing should be different, much narrower, reduced viscous drag. Ceramic ball bearings even better, as see on your WRC turbo.

Paul

cheers guys i think ill stay with my vf24 for know as it still produces over 350bhp..
gully

Gully

I think perhaps you need to get your clutch checked :D If the clutch is dragging then your car will show a high flywheel bhp due to the measured drag being excessive. Without knowing the Power at Wheels of your car it is difficult to verify your bhp figure.

I have observed a completely standard EVO7 showing a calculated 370 bhp on the rollers due to a dragging clutch on the rundown. The PAW was only 210 :D :D Oh how we laughed !