I have a turbo off a Cat LP engine. It has been measured to approx. the size of a T-64. No one can tell me what it is exactly. Cat won't, Garrett won't, turbo shops can't find anything. I was looking at some turbos (T6 series) and noticed they had about 7-8 blades on the wheel, and were more straight than angled in reference to 90* from the shaft. Mine has 15 blades all the same size, and are really laid over on the inducer side, but straighten up quick on the exducer side. I would post pics, but the turbo is at home, I'm at work. Anyone know what effect the blades being laid over will have on spool time, or efficiency?

 

I dont really have a technical answer for you (those are sure to come). I do know that the procharger P1sc-H with the helical impeller is for more low RPM boost (efficiency) at a sacrifice to high rpm boost (efficiency?) compared to the regular P1sc with its very straight cut outer blades. I hope that helps some. Makes sense to me considering the diesel application.

 

To make sure I understand you right, the straight blades are more for upper RPM efficiency, the more layed over or helical blades are for lower RPM efficiency. If that is the case, I wonder how fast I can get this thing to spool to keep the low RPM boost going.

 

yes that is my belief and I dont know

 

To greatly oversimplify things, straight blades work better at higher pressure ratios where curved blades typically work better at lower ones (which is what we want, for turbos “higher pressure ratios” is in the 45psi range)

 

Gooooood!! Then I am using it! Thanks for all your help guys. I'm looking at no more than 12-14psi, unless I'm feeling ballsy.