Great Moments in Cat History
10-12-2001 | 08:39 PM
#226
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Joined: Sep 2001
Posts: 596
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T2x, I agree that on the Cats, the Arneson’s and Kaama took some figuring out with the hydraulic tie-bar, on the V’s they both used a mechanical tie-bar same as Mercury. Both are truly trimable up and down. I have seen a cat with Arneson’s and a mechanical tie bar assembly recently and was told that they are now being offered.
I am confused at the direction of your statements. You stated that you had made a fixed surface drive, then list the weakness of the Arneson and Kaama as not being trimable?
How is a fixed drive trimable and a trimable one not?
I am confused at the direction of your statements. You stated that you had made a fixed surface drive, then list the weakness of the Arneson and Kaama as not being trimable?
How is a fixed drive trimable and a trimable one not?
10-12-2001 | 09:13 PM
#227
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Joined: Feb 2001
Posts: 211
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From: Tarpon Springs, FL
Adivanman wrote:
Case #1 – Two boats, 36 feet long tip to tip as measured by the APBA, one is a flat transom boat (Boat A), the other has an integrated swim platform 3 feet long (Boat B) with otherwise similar hulls and similar beaks. Both boats should weigh 8050 pounds and, on that basis, will be on par will all other boats. Problem is, Boat B is not 36 feet long – it is 33 feet long. Now, assuming that there is a relatively “constant” ratio of hull (from the transom forward) wetted on plane (the “running surface,” say 20 to 30% of the hull), there is 8% less hull in the water for Boat B and 8% less hull affected by hydrodynamic drag. Boat B must be faster than Boat A – all other things being equal. Now if Boat A, by APBA’s ascertain, represents parity with other boats based upon length vs. weight and Boat B is faster than Boat A, than Boat B will be faster than all other boats and there is no parity. This disparity becomes more pronounced for additions such as steps, raised delta pads, and hooked noses.
Andrew Corn Wrote:
Using your examples and calculations the 36’ boat (Boat A without swim platform) must weigh w/500EFI engines 8050# or by your method of calculation 223.61lbs per foot. The 36’ with a swim platform (Boat B) which according to Rule 27 “Hull and Deck Measurement Procedure” on page 37 would be measured at 33’ and w/500EFI be required to weigh 7675lbs or by your calculations 232.58lbs per foot. I’ll leave you to calculate the balance of the equations. I believe you will find that although the 33’ is smaller and lighter in total, it must support a greater ratio of weight on less area.
Adivanman wrote:
Case #2 – Two boats, 36 feet long tip to tip as measured by the APBA, both have integrated swim platforms, and both have steps. Boat B is a “flat transom” (below the swim platform), Boat C has a one foot deep delta pad raised one foot above the absolute base of the hull (the tip of the V). The reasoning outlined for case one would demonstrate one lack of parity here (as Boat C is shorter still), but there is another. Step bottom boats are not allowed extension boxes (as per the APBA rules) yet Boat C effectively has an integrated extension box. Will this make Boat C faster than Boat B by definition? Depends on the hull, however an extension box must represent some advantage, or the rules would not ban them for this hull design.
Andrew Corn wrote:
While and extension box may represent some advantage in some hulls and designs, the above mentioned boats are required to have a lower x-dimension than a standard hull that chooses to run an extension box. We have not found that there is a huge disparity between equal boats with steps and ones with steps and notches since x-dimension rules was implemented.
Adivanman wrote:
Case #3 – Two boats, 36 feet long tip to tip as measured by the APBA, both have integrated swim platforms, steps, and “flat transoms” below the SP. Boat B is a “conventional” beak boat while Boat F is a severely hooked beak. The logic presented in Case #1 should apply here, although according to the rules (in the past) these boats should have been equal. Forget the fact that Boat F had less cabin than Boat B – measuring tip to tip they were equal and, by the rules both on par. Boat F, however was always faster, despite repeated penalties and rule changes. Yet rather than admit that the length to weight rule had shortcomings, Boat F was effectively thrown out of the class and it’s manufacturer became the recipient of personal "attacks".
Andrew Corn wrote:
Lap times and results have not shown a huge disparity here either. This has been seen over the past year when rules have been enforced more aggressively and with the x-dimension changes. If boat F has been thrown out, it would be news to me, since I would be the one to write the letter. However that being said, if boat F did not meet the same configuration as the other like Boat F’s and the approved application for homologation for that model, it would not qualify. (Read aggressively enforcing rules.) As far as personal attacks, I’ll just address the tech issues and my own opinions while leaving the rest for others that were supposedly involved.
Adivanman wrote:
Plain and simple, a straight length to weight ratio does not ensure parity. It is just not that simple. One manufacturer that I can think of makes the most of the rules and is increasing its efforts in the class within the context of the rules. What will happen if that manufacturer becomes a dominant hull in 2002? Will it be “ruled out” as Fountain was? The rules need the attention – manufacturers build boats to the rules – if they don’t they should be disqualified. When they take advantage of the rules and are successful, well, that’s the point of racing.
Andrew Corn wrote:
Correct on the first point, but I believe that I have demonstrated that we don’t just look at straight line length to weight ratios. Second point, I don’t believe we have a dominant hull. I think this is proven in the past year and no Fountain model has been ruled out. However, any illegal boat or one that does not meet the spirit of the rules and the homologation criteria will not be allowed to race. In some extreme circumstances we have allowed boats to race with a parity penalty if a deficiency was minor or due to a manufacturing error or oversight. These are very thought out penalties by experienced techs, documented and agreed to by the owners.
Adivanman wrote:
This, needless to say, leads to the next question…What does the APBA want F1 and F2 to be? A competitive racing class/entity which seeks competition within the rules (like NASCAR or Formula 1), or does it want the class to be a “drivers class” and/or training ground (like ASA or IROC)? If absolute parity is the objective, cut another sponsorship deal and specify an exclusive hull (you have done it with engines and drives, you’re part way there), if not, look to fix the rules and let competition pave the way.
Andrew Corn wrote:
I’ll leave the business visions to others. I do believe that because of parity adjustments this year, coupled with aggressive enforcement of the rules, we have had some very equal and exciting races in these classes.
Andrew Corn summary:
I’m not sure where you are going with this, but it seems on one hand you advocate parity through rules, and as with most motorsports that have different manufactures we have made adjustments to the teams and hulls through the rules, and on the other hand you seem to complain about parity adjustments when we access them to the teams or manufactures.
Let me say, I enjoy the conversation, but I’m not sure that I share in your view of what is happening and by the number of registered boats in these classes, along with the racers, manufactures and fans that I talk to everyday, I’m sure the majority of them don’t either.
Andrew Corn
Director of Homologation and Documentation
APBA Offshore LLC
Case #1 – Two boats, 36 feet long tip to tip as measured by the APBA, one is a flat transom boat (Boat A), the other has an integrated swim platform 3 feet long (Boat B) with otherwise similar hulls and similar beaks. Both boats should weigh 8050 pounds and, on that basis, will be on par will all other boats. Problem is, Boat B is not 36 feet long – it is 33 feet long. Now, assuming that there is a relatively “constant” ratio of hull (from the transom forward) wetted on plane (the “running surface,” say 20 to 30% of the hull), there is 8% less hull in the water for Boat B and 8% less hull affected by hydrodynamic drag. Boat B must be faster than Boat A – all other things being equal. Now if Boat A, by APBA’s ascertain, represents parity with other boats based upon length vs. weight and Boat B is faster than Boat A, than Boat B will be faster than all other boats and there is no parity. This disparity becomes more pronounced for additions such as steps, raised delta pads, and hooked noses.
Andrew Corn Wrote:
Using your examples and calculations the 36’ boat (Boat A without swim platform) must weigh w/500EFI engines 8050# or by your method of calculation 223.61lbs per foot. The 36’ with a swim platform (Boat B) which according to Rule 27 “Hull and Deck Measurement Procedure” on page 37 would be measured at 33’ and w/500EFI be required to weigh 7675lbs or by your calculations 232.58lbs per foot. I’ll leave you to calculate the balance of the equations. I believe you will find that although the 33’ is smaller and lighter in total, it must support a greater ratio of weight on less area.
Adivanman wrote:
Case #2 – Two boats, 36 feet long tip to tip as measured by the APBA, both have integrated swim platforms, and both have steps. Boat B is a “flat transom” (below the swim platform), Boat C has a one foot deep delta pad raised one foot above the absolute base of the hull (the tip of the V). The reasoning outlined for case one would demonstrate one lack of parity here (as Boat C is shorter still), but there is another. Step bottom boats are not allowed extension boxes (as per the APBA rules) yet Boat C effectively has an integrated extension box. Will this make Boat C faster than Boat B by definition? Depends on the hull, however an extension box must represent some advantage, or the rules would not ban them for this hull design.
Andrew Corn wrote:
While and extension box may represent some advantage in some hulls and designs, the above mentioned boats are required to have a lower x-dimension than a standard hull that chooses to run an extension box. We have not found that there is a huge disparity between equal boats with steps and ones with steps and notches since x-dimension rules was implemented.
Adivanman wrote:
Case #3 – Two boats, 36 feet long tip to tip as measured by the APBA, both have integrated swim platforms, steps, and “flat transoms” below the SP. Boat B is a “conventional” beak boat while Boat F is a severely hooked beak. The logic presented in Case #1 should apply here, although according to the rules (in the past) these boats should have been equal. Forget the fact that Boat F had less cabin than Boat B – measuring tip to tip they were equal and, by the rules both on par. Boat F, however was always faster, despite repeated penalties and rule changes. Yet rather than admit that the length to weight rule had shortcomings, Boat F was effectively thrown out of the class and it’s manufacturer became the recipient of personal "attacks".
Andrew Corn wrote:
Lap times and results have not shown a huge disparity here either. This has been seen over the past year when rules have been enforced more aggressively and with the x-dimension changes. If boat F has been thrown out, it would be news to me, since I would be the one to write the letter. However that being said, if boat F did not meet the same configuration as the other like Boat F’s and the approved application for homologation for that model, it would not qualify. (Read aggressively enforcing rules.) As far as personal attacks, I’ll just address the tech issues and my own opinions while leaving the rest for others that were supposedly involved.
Adivanman wrote:
Plain and simple, a straight length to weight ratio does not ensure parity. It is just not that simple. One manufacturer that I can think of makes the most of the rules and is increasing its efforts in the class within the context of the rules. What will happen if that manufacturer becomes a dominant hull in 2002? Will it be “ruled out” as Fountain was? The rules need the attention – manufacturers build boats to the rules – if they don’t they should be disqualified. When they take advantage of the rules and are successful, well, that’s the point of racing.
Andrew Corn wrote:
Correct on the first point, but I believe that I have demonstrated that we don’t just look at straight line length to weight ratios. Second point, I don’t believe we have a dominant hull. I think this is proven in the past year and no Fountain model has been ruled out. However, any illegal boat or one that does not meet the spirit of the rules and the homologation criteria will not be allowed to race. In some extreme circumstances we have allowed boats to race with a parity penalty if a deficiency was minor or due to a manufacturing error or oversight. These are very thought out penalties by experienced techs, documented and agreed to by the owners.
Adivanman wrote:
This, needless to say, leads to the next question…What does the APBA want F1 and F2 to be? A competitive racing class/entity which seeks competition within the rules (like NASCAR or Formula 1), or does it want the class to be a “drivers class” and/or training ground (like ASA or IROC)? If absolute parity is the objective, cut another sponsorship deal and specify an exclusive hull (you have done it with engines and drives, you’re part way there), if not, look to fix the rules and let competition pave the way.
Andrew Corn wrote:
I’ll leave the business visions to others. I do believe that because of parity adjustments this year, coupled with aggressive enforcement of the rules, we have had some very equal and exciting races in these classes.
Andrew Corn summary:
I’m not sure where you are going with this, but it seems on one hand you advocate parity through rules, and as with most motorsports that have different manufactures we have made adjustments to the teams and hulls through the rules, and on the other hand you seem to complain about parity adjustments when we access them to the teams or manufactures.
Let me say, I enjoy the conversation, but I’m not sure that I share in your view of what is happening and by the number of registered boats in these classes, along with the racers, manufactures and fans that I talk to everyday, I’m sure the majority of them don’t either.
Andrew Corn
Director of Homologation and Documentation
APBA Offshore LLC
10-13-2001 | 12:17 AM
#230
Thread Starter
Allergic to Nonsense
Joined: Aug 2001
Posts: 5,007
Likes: 21
From: Granite Quarry, NC
Boatless: The fixed drives tend to come out somewhat lower in the hull than the Arnesons, because the CV joints required for trim and steering increase the diameter at the pivot point (transom). Therefore our fixed drives gave a more level angle of attack...meaning that we had a higher trim baseline. Arnesons either aim downward or simply raise out of the water when trimmed up rather than changing the propeller angle. This can be offset by greater prop rake but tends to be a compromise. Most steerable Arnesons I have flown behind tend to wander from lane to lane due to the aforementioned steering problems and length of the lever, so fixing them and adding a rudder is prudent at high speeds.... In fact most of the European/UIM boats have done just that. We chose fixed drives for our project primarily because of the enormous power (2 engines) we intended to put through each drive, the reduction in drive train parasitic power loss, and simplicity. If I were setting up a twin engine boat under 46' today Vee or Cat, I would use #6's.....my preference. A larger engine (big Diesels, turbines, V12's,) or boat (Sport Fisherman, Cruiser) application might send me toward fixed surface drives.
What exactly is your point here? The Arneson/Kaama drives have not been as successful in the performance/racing market as the Mercruiser stern drives or the Buzzi fixed surface drives for a reason. The public didn't buy them , they have odd steering and trim characteristics and they offer less control at slow speeds and while docking.....They are more efficient than a jet drive, however.
[ 10-13-2001: Message edited by: T2x ]
What exactly is your point here? The Arneson/Kaama drives have not been as successful in the performance/racing market as the Mercruiser stern drives or the Buzzi fixed surface drives for a reason. The public didn't buy them , they have odd steering and trim characteristics and they offer less control at slow speeds and while docking.....They are more efficient than a jet drive, however.
[ 10-13-2001: Message edited by: T2x ]
