Porting/Polishing the SN-series?

**Corvette91** · 03-13-2006, 03:29 PM

I’ve noticed that some people polishing the inside of their blowers. Would this make any difference for eg NoviGSS or SN2000? I’ve noticed that Speedytang reported 80 cfm up to 8 psi on a VR4, would the SN-series also gain similar amount of cfm or just a waist of time?

Does anyone have pictures on porting/polishing? Measurements on cfm increase for the SN-series would be very interesting too.

Rob

***speedytang*** · 03-13-2006, 05:47 PM

I have seen the housing(SN) extrude honed and they claimed a large increase in CFM. The only problem is a larger area for air volume means you need to push the blower faster to get the same PSI. I would figure a 1/4" decrease in Pulley size to increase impeller speed. You can port the housing with emery cloth which does the same thing for $250 less than extrude honing cost.

**Corvette91** · 03-13-2006, 06:37 PM

Originally Posted by speedytang

...housing(SN) extrude honed and they claimed a large increase in CFM.

Do you mean larger outlet diameter? (Sorry, my native language is Swedish)

My novice guess would be that one should not mess with the inlet diameter because its size is probably correlated to the impeller size. But I see no reason why increasing the outlet diameter would cause any problems (apart from a little lower boost pressure).

Originally Posted by speedytang

You can port the housing with emery cloth which does the same thing for $250 less than extrude honing cost.

I like the emery cloth option better :)

Thanks, Rob