Contour Enthusiasts Group Archives Forums Modifications Zetec Maintenance Optimized Zetec TB before and after pics

We can do batch pricing. However, a single valve cover is $150 shipped. The rest you have correct as far as regular prices. PM or email me.

Who did the work? Cost? Looks pretty, but the front bar is still there (no matter how thin it is) and the front edge isn't knife edged... A mirror finish isn't what is wanted for best flow either.

Both the front and rear of the throttle shaft were machined to make a flattened surface (6.4 mm thick) and the edges were chamfered. The screws are countersunk and have flat faces.

The visual band at mid height is the remaining original surface. The actual transition is a smooth curve in this region.

The surface was polished and chemically anodized using a method used to promote air flow in jet engine passageways. (I work as a materials/manufacturing engineer in the aerospace & transportation field.) On a flow bench the TB flows +18-20% better than stock over pressure drops ranging from 3-10 in-Hg.

The throttle plate was not given a knife edge finish for two reasons: 1/ I wanted the best transition during tip in and elected to keep the beveled edge with very small radii at the corners, and 2/ the best leading edge isn't a knife edge anyway. the best leading edge actually has a curved surface with compund radii.

The work was done by a retired machiist friend from work. It cost me under $100 even paying the friend for his time and it does improve flow without compromising part throttle driving.

Air in a TB works more like air over the surface of a golf ball than air/fuel through a jet engine. Totally smooth is not the way you want to go.

The beveled edge on the throttle plate I can agree with for the leading edge, but the leading edge of the TB housing I can not. Since the transition is not drawing from open air surrounding the edge, the best leading edge will result from the least amount of turbulence. A knife-edge there will create the wanted venturi effect against the silicone or rubber hose adapter going to the CAI/MAF/etc with the least amount of turbulent air. The only other way would be to eliminate this joint all together with a one-piece intake tube/TB/etc.

Still, very nice work.

I think you are quoting some useless facts that don't relate to airflow in a TB.

"Air in a TB works more like air over the surface of a golf ball than air/fuel through a jet engine. Totally smooth is not the way you want to go."

The air flowing through the TB behaves like air flowing through a tube which is what the center of the TB is. If you have golf balls in your TB you are probably going to have to repair the damage to the engine. The surface of the TB behaves more like the inner surface of bypass tubes on external jet engine hardware.

Now there are sharkskin like surfaces that you could put on the inner wall of the tube to minimize drag and improve airflow, although these structures work better with a denser fluid (liquid) than a compressible fluid like air. Slippery anodized surfaces work well enough and are used commercially.

"The beveled edge on the throttle plate I can agree with for the leading edge, but the leading edge of the TB housing I can not. Since the transition is not drawing from open air surrounding the edge, the best leading edge will result from the least amount of turbulence. A knife-edge there will create the wanted venturi effect against the silicone or rubber hose adapter going to the CAI/MAF/etc with the least amount of turbulent air. The only other way would be to eliminate this joint all together with a one-piece intake tube/TB/etc."

I have worked with aerodynamicists who have shown me that the best leading edge for subsonic flow is a complex curve, not a knife edge. A knife edge only has an advantage when it disappates the shock wave originating during transonic flow. If you have transonic flow in your TB you have an awesome engine. (sarcasm...)

In fact the inner diameter of the Iceman intake is slightly smaller than the inlet to the TB, so the top edge is hidden (the correct term is shrouded) from the airflow.

Your missed my point entirely about shaping the edge of the throttle plate so I got a good transition at 'tip-in' (throttle is just cracked above idle.) Only optimizing airflow at full throttle is not the best way to get driveability.

Anyway I built it, it has been flow tested and it works. Quit complaining.

I have been doing engineering a lot longer than you have... You need to go back to school...

I don't know half the things you said but stop being a troll. Brad has said nothing to attack you and you snap at him insulting his intelligence. We don't need that here. This is a discussion not a "I'm better than you" flame war. If that is what you want the CEG is not the place for you.

Amen to that.

BTW- no one on this board uses an Iceman set up. Most of us (who have an aftermarket intake) use an intake from CTA where the inner diameter of that tube is larger than the throttle body.

So I guess you are the one with "useless information."

You are a prefect example of why companies need sales people. Because if they let "engineers" like you talk to the general public, the company would go out of business.

Grow up sally.

The leading edge of the TB isn't an open-air leading edge, which is my point. The knife edge better transitions from the silicone or rubber adapter. Knife-edge makes the more gradual transition...

No, I didn't miss it. In fact, I agreed with it. Read it again...

Not complaining, until now. I said good work in fact. I was just pointing out what I could see as an area for improvement. You also mentioned you didn't build it, so now I'll complain about that...

Nope, not an engineer, I live in the school of life. No need to start questioning inteligence or backgrounds, but since you mentioned it... I can bet I've been hot rodding longer than you, how's 25 out of my 30 years? I've been snowmobile racing, motorcycle racing, car racing, flow bench testing, field testing, building, rebuilding, machining, etc since the age of 5. You mentioned people showed you the airflow characteristics, someone else did the machine work. Why waste our time with you, the middleman. Ask your friends to come join this conversation so that we might get some use out of it instead of squabbling about.

EDIT: I forgot to mention the air over a golf ball comment. The internal coated surfaces of a jet engine are in the portion of the engine that contain heat, fuel, and air, which all flow much differently than air alone through a throttle body. The surface of a golf ball, I'm sure you know, contains small circular divits to reduce air flow drag. Put similar divits in a TB, intake manifold, head ports, you get reduced air drag. Those things you can't do to an air/fuel/heat mixture, such as in a jet engine, because you'll get things like hot spots, fuel puddling... I'm sure you could name more reasons why you wouldn't want it... name one why we wouldn't in our "dry" intakes???

Are these goin to be made available for good at BNM or is this just a one time deal?

Cause I really want this and kinda need it cause I am gettin Terrys new turbo on and that would be a world of difference!!

Thanks!!

I think that about sums it up.

I agree. JonsZX2SR, if that's the way you hold an intelligent conversation, take a hike. We don't need your crap here if you can't debate a worthy issue with a worthy opponent. I didn't see anything derogatory from Brad; only from you. Adjust the attitude, or hit the door.