NemesisC5

Good stuff Tony!


https://www.scientificamerican.com/a...es-in-golf-ba/

How do dimples in golf ***** affect their flight?

Tom Veilleux, a senior scientist, and Vince Simonds, director of aerodynamic research at the Top-Flite Golf Company, explain.

Engineers and scientists in the golf industry study the impact between a golf club and a golf ball to determine the ball's so-called launch conditions. The impact typically lasts only 1/2000 of a second, but it establishes the ball's velocity, launch angle and spin rate. After this brief impact the ball's trajectory is controlled entirely by gravity and aerodynamics--no matter how much the golfer hopes or curses. As a result, aerodynamic optimization--achieved through dimple pattern design--is a critical part of overall golf ball development.

A smooth golf ball hit by a professional golfer would travel only about half as far as a golf ball with dimples does. Most golf ***** have between 300 and 500 dimples, which have an average depth of about 0.010 inch. The lift and drag forces on a golf ball are very sensitive to dimple depth: a depth change of 0.001 inch can produce a radical change to the ball's trajectory and the overall distance it can fly. Dimples have traditionally been spherical in shape, but it is possible to optimize the aerodynamic performance of other shapes. The HX golf ball by Callaway, for example, uses hexagons.


Air exerts a force on any object moving through it. Holding your arm out of the window of a moving car easily illustrates this phenomenon. Aerodynamicists break down the force into two components: lift and drag. Drag acts to directly oppose motion, whereas lift acts in a direction perpendicular to motion (it is usually directed upward in the case of a golf ball). As you rotate your hand in the air stream, you vary the amount and direction of the lift and drag forces acting on your hand.

A moving object has a high-pressure area on its front side. Air flows smoothly over the contours of the front side and eventually separates from the object toward the back side. A moving object also leaves behind a turbulent wake region where the air flow is fluctuating or agitated, resulting in lower pressure behind it. The size of the wake affects the amount of drag on the object. Dimples on a golf ball create a thin turbulent boundary layer of air that clings to the ball's surface. This allows the smoothly flowing air to follow the ball's surface a little farther around the back side of the ball, thereby decreasing the size of the wake. A dimpled ball thus has about half the drag of a smooth ball.

Dimples also affect lift. A smooth ball with backspin creates lift by warping the airflow such that the ball acts like an airplane's wing. The spinning action makes the air pressure on the bottom of the ball higher than the air pressure on the top; this imbalance creates an upward force on the ball. Ball spin contributes about one half of a golf ball's lift. The other half is provided by the dimples, which allow for optimization of the lift force.

Answer originally posted January 5, 2004.

Blvdbrawler

Hey, just curious if anybody had a vitesse and switched to this TB or use in conjunction? Which is better? Can you both at the same time? Any info would be appreciated.

Tony @ Mamo Motorsports

Its been done and not successfully....

First off a Vitesse is just an electric bandaid that messes with the throttle speed....it does nothing to correct all the inherent problems associated with the stock TB (primarily the horrendous shape of the OEM housing bore).

It does not add any CFM (zero gains in actual airflow) and is worth absolutely nothing in power or torque gains. My ported TB on the other hand adds an additional 150 CFM of airflow in front of that hungry blower which then compresses and feeds the cylinders with a denser charge (and that represents a significant improvement....15% increase over stock and that's why this mod adds real power and torque to your bottom line).

I know what your thinking now....how about both perhaps? Essentially it becomes an instant code thrower....now you have a very optimized TB (moving alot more air) that's opening even faster with the Vitesse and the engine just sees waaay too much airflow (especially at the lower throttle positions) and the ECM waves big flag in the form of a CEL or potentially going right into limp mode.

Hope this answers your questions and helps you better understand the physics of "why"

The TB is a much better upgrade....it does everything the Vitesse does and a whole lot more and is actually doing it be eliminating the problem (not trying to mask it) and also improves the volumetric efficiency of the engine....this is a real airflow mod not unlike swapping to a better set of cylinder heads or a ported blower etc.



Regards,
Tony

robert miller

^^^ But then again those guys could get a COW also.

badhabit_wb

I sent Tony an email on Black Friday late in the afternoon. I asked about the off idle lag I was experiencing and had experienced since I bought the car, a 2015 z06. Tony told me the throttle body would solve the issue and I decided to order one. I told Tony that I probably wouldn't get a chance to drive the car until the spring but today I had a few hours to burn and decided to go to a Cars and Coffee.
I'd disconnected the battery while I installed the throttle body so it took a few minutes for the ecm to get sorted out and I also had to re-index the windows. I drove around for about 3 hours and I can say one thing for certain. The car performs like a different vehicle off idle. There was a lot of stop and go driving and I started just letting the car start, except on an incline, without using the throttle or rev matching. The car pulled away from a stop every time without stalling. I couldn't believe it. In the past the car would have stalled, multiple times. I've tried starting off without using the throttle in the past and unless I used rev matching it stalled most times. Even with rev matching it occasionally stalled from a dead stop. Today it ran like it should have. Flawlessly. I didn't push the car hard and I was mostly concentrating on starting and stopping. I can't tell if the car has more hp or if it's faster in the 1/4 mile. I can say it's a lot better in stop and go driving. The off idle performance is so much better than it was that I can say the throttle body would be a bargain at twice the price. I haven't modded the motor other than the tb and gm secondary radiator. Everything else on the motor is just like it came from the factory. The only regret I have is that I didn't buy the throttle body and install it the minute I got the car home.

MacRoadie

Just ordered mine.

BlackMoon

Ordered mine last week. Can't wait to put it on and try it out. Are they plug & play or does the PCM need to 'learn it"?

charliebrown266

you guys are going to love it! had mine for a year now!

MacRoadie

C7/Z06 Man

I would wait to see if you do/keep getting a light before flushing your new car warranty down the toilet with a GM readable tune. You know the GM computer can adjust up or down approx. 25%. That is why these cars can run just fine in Alaska on a cold winter day or Death Valley. As far as performance goes "I" have no complaints running the OEM tune.

The other thing you can do if its just one of the two mods that lights the light. Than you may want to consider just removing the one.

MacRoadie

Steve Snake Driver

Another happy Mamo ported-TB user. Installed it last night and got out and around in the car today. This how the car should have been from the factory!

saleen556

badhabit_wb

Mine is an m7 and it's a big improvement. I didn't change filters or install a cai so I don't know how it would work with that. It does make a world of difference in throttle lag. I highly recommend this mod!

Steve Snake Driver

Yes, M7. Stock filter, but I do have the GM 'Jake' air box/intake on order.

DavidC83

I installed my TM PTB and BMS filter and man, its a new car now, even with the A8. It's noticeable without question. I also have the borla x pipe and that's it for performance mods for me

saleen556

DavidC83

you will not be disappointed

SLEEKVET

I have an A8 and interested. Did you install the filter and TB separately or at the same time?

DavidC83

I had the TB on for about a week before the filter arrived. The TB made a noticeable difference in off idle acceleration and response, but when I added the filter the car just completely came to life. Its most noticeable for me in the late-low to mid range as I haven't had the place or weather to really stretch her legs yet. I can only image what the 3-4 gears feel like WOT.