TBPNews #74 - February 8, 2005
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In this issue: 
1) Gary Garbrecht dead
2) Yamaha wins dumping case
3) Boat Racing on TV
4) Ken Warby Runs The WWSR Jet Boat - Video!
5) FEATURE ARTICLE - What a drag! - Trim angle & engine height can reduce drag & increase speed. 
6) Jimboat writes Feature articles in HOTBOAT & F&PB magazine
7) 'Hot Boat' magazine - Save 51%! 
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1) Gary Garbrecht dead

Gary Garbrecht, the embattled former owner of Hydro-Prop, Inc., died from an apparent heart attack Sunday in Florida.  According to published reports, Garbrecht was playing golf with his doctor when he suddenly collapsed with an apparent heart attack.  Attempts to revive him were unsuccessful.

A former Unlimited hydroplane owner and CEO of the Formula One series of outboard boats, Garbrecht purchased the sport of Unlimited Hydroplane racing from the APBA in 2000 along with former Miss Budweiser owner Bernie Little.  

He was a charming, successful and forceful figure in the glory days of OPC and Unlimited racing.  He began his career with Mercury in 1964 and four years later, started the company's factory racing team. When the team disbanded in 1979, Garbrecht took over Mercury's newly-created High Performance Division. He left a year later to join forces with Reggie Fountain and develop a new line of offshore powerboats. After that, he formed his own company, Second Effort.

While initially hailed as the struggling sports savior, his personal style and business decisions quickly turned off fans and competitors alike. Before the 2004 season began, one race site (Evansville) pulled away from Hydro-Prop and was quickly followed by two others. After the season finale at St. Clair in August, Garbrecht sold his interests to Florida businessman Trent Ling.

Garbrechts funeral will be at 11 a.m. Saturday Feb. 12, 2005 at the Oak Ridge Funeral Care Center in Winter Haven Fla.
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2) Yamaha wins dumping case

The United States International Trade Commission today voted to reject Brunswick Corp.s dumping claims against outboard engine manufacturers from Japan, finding no basis for its claims of injury.  It represents a victory for Yamaha Motor Corp., which had led the defense against a price dumping complaint filed a year ago by Brunswick Corp, the parent company of Mercury Marine. 

Mercury president Patrick C. Mackey indicated he found the ruling hard to fathom. Given the substantial evidence of harm to the industry presented by Mercury, we are disappointed with the ITCs decision, Mackey said in a statement. Dumping was proved and we demonstrated that our outboard unit has suffered since 2000, so we dont understand how this conclusion was reached.

Mercury Marine filed the petition last Jan. 8 with the ITC and the Department of Commerce. The Lake Forest, Ill.-based company alleged that outboard motors and powerheads from outboard motors from Japan were being dumped into the United States.  The Commerce Department issued a preliminary determination last August that there was a pricing margin of 22.52 percent, and ordered all Japanese outboard manufacturers to post bonds in that amount of any engine imported into the United States. It was up to the ITC, however, to determine whether or not the American companies were injured by the dumping. Since no injury was found, the bonds that were collected will be released and refunded to the affected companies. 
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3) Boat Racing on TV

Friday, February 11, 2005 Time: 06:00 AM EST - TV The Outdoor Channel - Speedzone - "ChampBoat Series from Bay City, Michigan"

Saturday, February 12, 2005 Time: 5:00 PM Eastern - TV The Outdoor Channel - Speedzone - "ChampBoat Series racing from Bay City, Michigan"

Tuesday, February 15, 2005 Time: 10:00 AM - TV SPEEDTV - "UIM F1 Powerboat Series - Season Review"
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4) Ken Warby Runs The WWSR Jet Boat - Video!

22 Jan 2005 - Taree NSW; A special first look at Ken Warby running his jet boat for some test runs. Ken is the current world record holder for the fastest person on water, and he's looking to beat his own record in the new boat. Aussie Spirit had a very successful test on the Manning River - Taree.  All systems functioned faultlessly.  Acceleration rate and speed was slightly increased on the previous test.  Boat characteristics continue to be as desired.  It is planned that the next tests to be at conducted during Easter 2005 will be more of the same, slightly increasing acceleration and speed. (Thanks to Scream&Fly Online for video reference)

FREE (5MB) video of test run:  http://www.screamandfly.com/video/warby_test/warby.wmv
More info on Ken Warby: http://www.kenwarby.com
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5) FEATURE ARTICLE - What a drag! - Trim angle & engine height can reduce drag & increase speed. 

To get the most from your high-performance powerboat setup, motor placement and motor trim angle are just as important as horsepower and propeller selection.  Hydraulic/electric power trim and power lift accessories have made the fine tuning of high performance powerboats a uncomplicated reality for everyone.

The hydraulic drag generated by the motor lower unit or outdrive appendage can make or break your hulls performance.  If you can raise the motor higher, so that there is less unit in the water, then there is less drag  and more speed!  The thrust that propels your hull to the checkered flag is most efficient when if is aimed exactly in direction of boat  so motor trim angles of 1 degree up or 1 degree down can hurt performance. 

Trim Angle 
The most efficient trim angle  as far as engine thrust and drag goes  is exactly neutral.  So, if we can design and/or set up our hull so that it runs properly with the motor/drive unit trim at zero, then we will have the ideal situation.

The difference is not trivial.  Lets consider the effect of even small trim angles.  First, a trim angle of positive 2 degrees  meaning trim creating a bow-up condition of the hull  which means that the lower unit torpedo is angled down at a 2 degree angle.  For a 200hp outboard engine, the difference in forward thrust lost is about 7hp!

The same type of problem can occur with a trim angle of negative 2 degrees  meaning trim creating a bow-down condition of the hull  which means that the lower unit torpedo is angled up at a 2-degree angle.  In this case the power is not being fully applied in the straight-ahead direction, but rather, some of your power is actually being used to raise the aft end of the hull (vertical).  Both of these conditions can be avoided with proper hull design and/or setup.

And thats just power loss  there is also increased profile and induced drag of the lower unit.  At 60mph with this engine, this will amount to another 1 hp for this lower unit angle.

So total, we have experienced a power penalty of 8 hp (4%) resulting from our trim angle.  Translated into speed loss, for a typical performance ModVP hull this will mean a reduced top speed by 2 mph!

Motor height
Adjusting the height of the motor (lower unit) has a big influence on total hydrodynamic drag.  In an outboard, this is often done with a manual or hydraulic jack plate.  On an IO, this is adjustment is referred to as the X-dimension.  In all cases, when the drive unit is lower in the water, there is more drag generated.

A common starting point for adjusting the setup lower unit height for high-performance hulls is for the torpedo centerline to be level with the trailing edge of the planning surface.  Too high and the propeller can over-cavitate, too low and the setup will generate excessive drag. 

Lower Unit (or torpedo) heights, called X-dimension, can be adjusted on inboard/outdrive setups using different-height lower drive units.  These are available from high performance suppliers.  Its not as easy as using a hydraulic jack plate on an outboard, but it now makes the height adjustment a possibility, where it was almost impossible a few years ago.

Lets consider a setup where the torpedo centerline is one inch (1) below the trailing edge of the planning surface (sponson or pad).  At 60mph, and our 200hp outboard engine, this will generate an additional 9.0 pounds of drag  equivalent to another 1.5hp loss.  

But, theres more.  If your hull setup is using a surfacing propeller (most performance hulls can benefit), then there is an additional propeller drag increase by submersing more of the lower unit (and thus, the propeller) under the water surface.  In the case of an additional 1 below the planning surface, this can affect the thrust transmission efficiency  which can lower your available engine RPM by as much as 5%.  This can easily represent 300 RPM  or another 6hp loss!

Translated into speed loss, for that typical performance ModVP hull this means a top speed further reduced by 2 mph!

In summary, by being able to trim to the optimum angle, and having the lower unit set at the optimum height, we can make a significant improvement on performance!

** This article was originally published in September 2004 issue of HOT BOAT Magazine - "What a Drag" - Trim Angle & Engine Height Can Reduce Drag and Increase Speed", by Jim Russell, author of "Secrets of Tunnel Boat Design book [editor-HB].  Or get your own copy of the full-color feature article at: http://www.aeromarineresearch.com/adverts/HotBoat_Sept2004.html
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6)  Jimboat writes Feature articles in HOTBOAT & F&PB magazine
"10 Smokin' Speed Secrets Revealed..." - Jimboat has new article in February 2005 HOT BOAT magazine. "If you don't want to make expensive modifications to your hull or engine setup, then here are some tips for getting the most performance from your current setup.  By Jim Russell, author of "Secrets of tunnel Boat Design" [editor-HB]
Check it out at: http://www.aeromarineresearch.com/adverts/HB_Feb2005.html

and Recently published...

"Winterizing your Performance Outboard" - Jimboat has new article in Jan2005 issue of Family & Performance Boating.  Check it out at: http://www.aeromarineresearch.com/adverts/F&PB_Jan05.html

"What a Drag" - Trim Angle & Engine Height Can Reduce Drag and Increase Speed", by Jim Russell, author of "Secrets of Tunnel Boat Design book [editor-HB].  See September 2004 issue of HOT BOAT Magazine.  Or get your own copy of the feature article at: http://www.aeromarineresearch.com/adverts/HotBoat_Sept2004.html

"10 Safety Tips" - The author of "Secrets of Tunnel Boat Design" offers ten safety ideas for high performance go-fast boats [editor-HB].  See August 2004 issue of HOT BOAT Magazine.  Or get your own copy of the feature article at: http://www.aeromarineresearch.com/adverts/HotBoat_August2004.html
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7) 'Hot Boat' Magazine - Save 51%! 

We have obtained great deals on Powerboat magazine subscriptions. This month we have a great deal on the popular 'Hot Boat' magazine. 

'Hot Boat' Magazine - High-performance boaters bible featuring tests, technical reviews, adventure travel, racing coverage, product reviews and tips. 11 issues, Cover Rate, $54.89; Our Rate Only $28.95. That is 47% off!
 
http://www.aeromarineresearch.com/boating%20magazines%20discounts.html 
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See you next time!

/Jimboat

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Note: The articles presented in TBPNews are edited excerpts from the "Secrets of Tunnel Boat Design" book, by Jim Russell, published by AeroMarine Research.  The STBD book explains the theory in full, and outlines example design calculations, step-by-step.  The "Tunnel Boat Design Program", software, does all the force calculations, dynamic force balances at all speeds, and reports the analysis automatically, including complete graphical performance results for any tunnel or modified vee hull design.
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