Phoenix GSR

as the topic says, where do you guys get your compressor housings polished? or do you do it yourself? it seems it would be hard to polish down in the small places..

tia

pissedoffsol

are you talking bling factor, or internal for flow?

cornbread

I polished mine myself using these instructions. Took me 4 hrs with a die grinder.

Materials and tools needed:
1) 1 pack of 220 grit automotive "wet" sandpaper
2) 1 pack of 300-320 grit "wet" sandpaper
3) 1 pack of 400 grit "wet" sandpaper
4) 1 pack of 600 grit "wet" sandpaper
5) 1 pack of 1000 grit "wet" sandpaper
6) 1 pack of 1500-2000 grit "wet" sandpaper
7) 1 small can of Mothers Mag & Alluminum polish

Note(you wont need much of any of the paper. Buy the smallest & cheapest packs avaiable)

If you have access to a die grinder, USE IT! It will cut a few hours off the time. Use it with a rolok disk. Either the purple(alluminum) or brown(steel) Be carefull with the brown
disk. It will cut through alluminum very quickly. If you are not confident using a die grinder, I suggest doing the job totally by hand.

Using either the die grinder or 220 paper smooth out the casting marks. Sand out any numbers or letters on the housing. This is the worst part of the job if you dont have a die grinder.

Next, use the 300 grit. Get a bucket of water and a chair. Start wet sanding all the scratches out. Clean the housing and the paper often in the bucket of water.

Continue with the 400 and 600 grit in the same way. The housing will get smoother and smoother with each grit. And the bucket of water will be about black at this point.

Now the 1000 grit. Same way, with the water. At the end of this step, the compressor housing will be pretty shiny, and as smooth as glass. Your fingers, on the other hand, will be sore, black, and pruny.

Final sanding is 1500-2000 grit. This will take out any surface sratches. and leave the housing perfectly smooth. When your done, clean the housing with soap and water.

The housing will look great at this point. Super shiny. Time for it to look like a mirror! Crack open the Mothers mag and alluminum polish. Mothers also has a new polish called BILLET Polish, which I think does a better job. Grab some rags and go to town. The end result will amaize you.

B18Flip

wow, thanks shane......i just saved that to my notepad

quikB18B

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B18Flip &raquo;</TD></TR><TR><TD CLASS="quote">wow, thanks shane......i just saved that to my notepad </TD></TR></TABLE>

Me too

I've been planning on doing mine, but i've been to lazy to take everything apart

I did my Intercooler couple weeks ago, pretty much used the same steps Although im not 100% done, im going to go at it again this weekend for the final sand.

Iggy who doresn't have the desire to sit for 4 hours and sand, so he does a little bit at a time

cornbread

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B18Flip &raquo;</TD></TR><TR><TD CLASS="quote">wow, thanks shane......i just saved that to my notepad </TD></TR></TABLE>

No problem, i had mine in my car the other night when we met up to check out the intercooler could have shown it to you. It' so "bling" i don’t want to put it on the car.

Phoenix GSR

do you have any pics of a hand polished turbo?

m R g S r

Good info, thats the same thing I did to my valve cover and it looks sickk.

stackz

or go to a local sandblasting shop and pay $5.00 to have it media blasted, then head over to the local chroming shop and pay $15.00 to have it chrome-plated for the ultimate bling bling and best flow you'll ever get.

chrome = ultimate smooth compared to polishing and covers EVERYWHERE!

tolerance bother you? media blasting will take up to .005 off the surface and chrome plating only adds .001 to it!

oh, and if a shop quotes you any more than what I said for those 2 prices they are trying to rip you the HELL off. I had one shop quote me $70 for the chrome-plating on the compressor housing

FOrSfEd

I think there are a couple people on the board that does it as well

dasher

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by stackz &raquo;</TD></TR><TR><TD CLASS="quote">ultimate bling bling and best flow you'll ever get.

chrome = ultimate smooth compared to polishing and covers EVERYWHERE!
</TD></TR></TABLE>

a glass smooth surface which chroming will produce as stated above will actually hurt flow. Slightly rough surfaces support laminar flow and create a thin boundry layer. A good head porter will not actually "port and polish" your head ... 60 grit is a good smoothness to port to...

88gts

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">a glass smooth surface which chroming will produce as stated above will actually hurt flow. Slightly rough surfaces support laminar flow and create a thin boundry layer. A good head porter will not actually "port and polish" your head ... 60 grit is a good smoothness to port to...</TD></TR></TABLE>


Yeah and this is when there is fuel and air involved in the process. Have you ever seen a nice 60 grit polished airplane wing? Thas what I though.


Anyway i just wanted to add that I used to work for stanley mechanics tools and obviously they do quite abit of polishing as tools go from raw as forged as cast states to nice shiny pieces ready for sale. They had huge vibratory tumblers that they would tumble parts in with various media to polish and deburr etc.. If you can find a place that will do this they may be able to tumble your housing to make it a nice shiny piece or at least get it closer to a full polish. I think abit of it is still done by hand regardless. I have no idea what effect this would have on the interior surfaces of the compressor housing. I dunno what tolerances are required in there.

dasher

This is not just where there is air and fuel present .... these are the properties that air-fluids exhibit when flowing over surfaces ....

Air tends to "stick" and cling to a polished smooth surface and cause turbulence disrupting the laminar flow above the boundary level ... this is fairly well known.

I know its hard for some individuals to conceptualize because it goes against whats naturally seems right:for another example ask yourself why golf ***** have dimples instead of being smooth?

In regards to your airplane wing example: 3m makes a product called "Rivelets" which are V shaped bumps which can be used on airplane wings or sailboats to decrease parasitic drag.... you have to factor in costs and labor when understanding why airplane wings get by with flat sheet metal....

88gts

No its not that I cannot conceptualize this it goes against everything I and several other major players in the industry have done for many years now. Nopt saying that I am a major player I personally am not..generally the intake ports are roughed up and the exhaust ports are polished. I learned this from a guy who has been porting heads for many many many years now(20+). The polished compressor housing may indeed exhibit(sp?) the characteristics you speak of but I seriously doubt you will notice the difference between one or the other. In other words the difference may be there but it will be very hard to measure. OTH the compressor housing will look much more pleasing to the eye.


The aircraft industry is not known for cost cutting at all. Not with regards to how the aircraft will perform and safety etc.

dasher

So you now are agreeing with me that it will hurt flow quality.... but are willing to take a minimal flow loss as well as altering the internal tolerances to have a bling, bling compressor housing??? If you really need a pretty compressor housing: how about the alternative- some exterior sanding or paying a few extra dollars at the time of sale- cheapturbo.com will ship a polished compressor housing for an extra 60 bucks.

To each his own I guess....

In regards to the airline manufacturers : safety and costs are much more important than performance ... it is important to realize that these are businesses where making a profit is their primary concern.


Modified by dasher at 11:36 PM 3/6/2004