I was doing an internet search for a GM throttle body because I needed to see what the inlet looked like without going out to my truck and popping the hood. The first thing that came up was this site: polished GM throttle body It shows a throttle body that has been polished on the inside. Why would someone waste their time polishing the inside of a TB if you can't even see it. I have read that it is better to have a little roughness on the surface to disturb the air.
Polished throttle body
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I don't see any throttle body there.
A slight roughness is usually better and has to do with laminar and turbulent flow. Years ago people polished the intakes to a mirror finish and then some German or Englishmen with some physics background discovered that the satin finish increased flow. All racing engines I've seen have intakes with the inside satin finished.
ls1mike
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I didn't either. There was one?
I bought my ported TB from Katech, as they were blowing them out for $99.00 with NO core charge, so I got to keep my stock one as well.
It has a satin/'turned' finish on the inside (they did not even offer a fully polished version, although others obviously do).
Katech being LSx engine builders extraordinaire (i.e.; builders of the C5R/C6R race engines), may bear proof to your theory that a rougher finish is better than a smoother/polished one.
It has a satin/'turned' finish on the inside (they did not even offer a fully polished version, although others obviously do).
Katech being LSx engine builders extraordinaire (i.e.; builders of the C5R/C6R race engines), may bear proof to your theory that a rougher finish is better than a smoother/polished one.
Originally Posted By: dailydriver
I bought my ported TB from Katech, as they were blowing them out for $99.00 with NO core charge, so I got to keep my stock one as well.
It has a satin/'turned' finish on the inside (they did not even offer a fully polished version, although others obviously do).
Katech being LSx engine builders extraordinaire (i.e.; builders of the C5R/C6R race engines), may bear proof to your theory that a rougher finish is better than a smoother/polished one.
I agree about the "turned" finish. Perhaps a turned Trick Flow piece?
I bought my ported TB from Katech, as they were blowing them out for $99.00 with NO core charge, so I got to keep my stock one as well.
It has a satin/'turned' finish on the inside (they did not even offer a fully polished version, although others obviously do).
Katech being LSx engine builders extraordinaire (i.e.; builders of the C5R/C6R race engines), may bear proof to your theory that a rougher finish is better than a smoother/polished one.
I agree about the "turned" finish. Perhaps a turned Trick Flow piece?
really polished surfaces do not flow as well as properly roughened ones due to laminar flow characteristics.
Been the industry standard in cylinder heads and other intake parts for years.
Been the industry standard in cylinder heads and other intake parts for years.
Any 'industry standard' is for mass production, and to meet the general flow requirements.
It is not for best flow or power.
Polishing takes a lot of time - LOTS of tedious work.
No way will factories do this.
Polishing TBs and cylinder heads can help flow, for sure.
Roughness slows gas down. A bit of roughness was good on carbureted cars in the intakes - it helped mix the fuel/air.
Exhausts are always best polished, as ar modern intakes with fuel injection.
It is not for best flow or power.
Polishing takes a lot of time - LOTS of tedious work.
No way will factories do this.
Polishing TBs and cylinder heads can help flow, for sure.
Roughness slows gas down. A bit of roughness was good on carbureted cars in the intakes - it helped mix the fuel/air.
Exhausts are always best polished, as ar modern intakes with fuel injection.
you need an update from a real tuner or engine builder.
Note the wording: "properly roughened". Super smooth polished does not flow as well, period. It's a fact.
I'm NOT talking mass produced. I'm talking expensive, go-fast stuff. Those with the big bucks heads, intakes, etc. use a smoothed surface that appears polished but is actually dimply on a near microscopic level. This allows MORE airflow.
Note the wording: "properly roughened". Super smooth polished does not flow as well, period. It's a fact.
I'm NOT talking mass produced. I'm talking expensive, go-fast stuff. Those with the big bucks heads, intakes, etc. use a smoothed surface that appears polished but is actually dimply on a near microscopic level. This allows MORE airflow.
I learned all about that stuff thirty years ago on my dirt bike. I polished the intake and tested, polished and tested some more. There came a point where it got worse, and that was when I'd gotten it the shiniest. I had to go back and rough it up.
However, when I polished my own tb on my Z28, I didn't go the chrome-like shine route. Also, while I was working on it I increased the size of the port a little. That's a good portion of what the polish/port job is all about.
However, when I polished my own tb on my Z28, I didn't go the chrome-like shine route. Also, while I was working on it I increased the size of the port a little. That's a good portion of what the polish/port job is all about.
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