Anyone tried to do this themselves? i'm not quite sure who locally can do it for me in okc. I'm sending my bb 5857 back to precision to get upgraded to a bb cea 5858. They say it will spool faster and make better power but while my car is down i'd like to have the compressor side polished while its out of the car.

anyone use the wheels polisher kit they sell at autozone? flame suit on

 

I polished the cast aluminum intake manifold/throttle bodies/misc brackets on my 300zx by hand. I would image the compressor housing would polish very much the same. It's not hard, just a royal pain in the ass.

I started with 100 grit wet sandpaper, and just moved through the grits, making sure all sanding marks from the previous paper were removed before moving onto the next grit (100->200->400->1000->2000). Finally, I used one of the buffing compounds and wheels that go into a drill for the final polish. It came out pretty good (you really need to make sure all sanding marks are gone before the next grit, otherwise you'll always see them), but holy crap was it tedious. I probably had 40-60+ hours of just sanding by hand.

With that said, a turbo compressor housing isn't too large, so a few hours each night sanding while watching TV (what I did) and you can probably have it done after a week..


Slightly dirty, but this was my final product:

 

40-60 hours?!?!? just pay someone to do it

 

Anyone have good experience with a shop they'd like to share?

 

Dont do polishing on a housing turbo or sc...
I did it,the housing heat and will wave( mine waved of 4/1000)
Impeller hit the housing..
You dont want that..

 

you sure? i've seen alot of polished turbo compressor housings. im not polishing the hot side. just the compressor cover

 

Well a compressor housing is much simpler/less intricate than my intake manifold, so I would hope it wouldn't take nearly as long. I would also imagine that a shop would have air tools or something similar to at least speed up the process with the lower grits. With that said, there's a reason polished housings are typically a $300+ upgrade, as the process of polishing a sandcast aluminum piece is labor intensive.

I also don't see how the polishing would change the heat characteristics enough to make the compressor warp. You're only taking off a fraction of an inch of metal, and while there will be slightly more radiant heat, I cant imagine it would be 100s of degrees different...

 

Personnaly,i would not do it again..
Mine was a vortech blower...not a turbo
It has been done with a polishhing buffer..that thing heat...and aluminium is easy to heat..

 

That sounds ridiculous. I've polished compressor housings. You won't damage it. The pain is repolishing it constantly.

 

i talked with precision and I was sending them my bb 5857 to be upgraded to a bb CEA 5858 and while they have it they are going to polish the compressor housing for $75. should have it back in 2 weeks or so rebuilt. Now I need to get that Ptuning Oil Distribution Block and redo my oil line setup