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badtrip25
03-22-2002, 01:18 AM
I have talon 25 equipped with 225 HO Johnsons
14 1/2 32 cleavers and fiber reeds
my boat is going 93 mph is ok for this boat?
please tell me

HavasuDreamin'
03-22-2002, 05:50 AM
That seems to be cookin' pretty good especially for OMC's http://free.***boat.net/ubb/wink.gif What kind of RPM's are you turning those 32 inch cleavers?

badtrip25
03-22-2002, 05:54 AM
6700 rpms

HavasuDreamin'
03-22-2002, 06:32 AM
Alright, something is not adding up here! I ran your numbers through the mathematical calculation and came up with about 15% slip which is too much! What gear ratio in the lower units? I used 6,700 RPM and 1.86:1 gear ratio. At 10% slip which is the general rule of thumb, you should be running 98.24 mph. How did you measure speed? Speedometer or GPS? Are you sure your tachometer(s) are accurate?
Here is the mathematical formula for all those who are interested:
(Motor RPM/Gear Ratio) x Prop Pitch
Divide that No. by 5280 and then again by 12
In your case the number is 1.819......
Take that number and multiply by 60! This is your theoretical speed without slip. Subtract slip of 10% or whatever.
You can also figure out slip factor if you know how fast you are actually going. Divide actual mph by theoretcial mph (no slippage). Subtract the resulting number from 1 (in your case 1-.851991045=14.8%)
Good Luck!

MrHavasuCat
03-22-2002, 08:47 AM
I would say that is a pretty good number. My 2000 Mach 26 with twin (280 hp) merc 2.5's ran a best of 106 at 7500 rpm's. Your slip numbers are higher than mine, but we are talking about merc racing motors with sportmaster gearcases versus OMC. I ran the best speed with my 15x30 3 blade labbed cleavers. I had some round ear Lightning et's for holeshots, but I think the cleavers ran better overall.
BTW: I think the talon is a very nice boat. My engine builder has a 25, and the boat is very solid and the glass work is very good.
[This message has been edited by MrHavasuCat (edited March 22, 2002).]

gimprvr
03-22-2002, 09:32 AM
Hey Badtrip25 how does your boat turn? I hear the Talon has one of the best turning bottoms for a cat on the water. Is this your experience?
Anyone else wish to chime in?

hulshot
03-23-2002, 11:06 PM
I have a boat based off a talon, its a howard cat. It turns very well and doesnt tend to slid or leanto the outside. handles rough water very good as well.

boatnam2
03-23-2002, 11:21 PM
i had a american offshore which is from a tallon and it would throw you on the floor it turned so hard.

badtrip25
03-24-2002, 07:27 AM
Originally posted by HavasuDreamin':
Alright, something is not adding up here! I ran your numbers through the mathematical calculation and came up with about 15% slip which is too much! What gear ratio in the lower units? I used 6,700 RPM and 1.86:1 gear ratio. At 10% slip which is the general rule of thumb, you should be running 98.24 mph. How did you measure speed? Speedometer or GPS? Are you sure your tachometer(s) are accurate?
Here is the mathematical formula for all those who are interested:
(Motor RPM/Gear Ratio) x Prop Pitch
Divide that No. by 5280 and then again by 12
In your case the number is 1.819......
Take that number and multiply by 60! This is your theoretical speed without slip. Subtract slip of 10% or whatever.
You can also figure out slip factor if you know how fast you are actually going. Divide actual mph by theoretcial mph (no slippage). Subtract the resulting number from 1 (in your case 1-.851991045=14.8%)
Good Luck!
hi thanks for your reply
I have 1:86 gear ratio and gafrig speedo
tachs are ok but one engine rpm lower 200-300 rpm lower what can be the problem?
how can i reduce my slip?
gear cases are nose coned and its mounted 2.5 inches above the lowest point.
thanks

Blackdog
03-24-2002, 06:43 PM
The 225HO's make 247hp at the prop shaft. You need to work on the slippage. Maybe try somebody else's props. Also get with a OMC guy and take the rev limiters off those motors and let em eat. You should see 96 or 97 if the boat is not to heavy.

ratso
03-24-2002, 07:11 PM
Contact Rapair to remove the rev limiters.

HavasuDreamin'
03-25-2002, 09:56 AM
I am not familiar with set-up on Talon Boats, but the propshaft 2.5 inches above the lowest point on the boat seems high. Most boats run the prop shaft at the same height as the center pod, perhaps slightly higher. How much water pressure are you seeing in your motors? I run my Merc at 12 PSI or better. Every once in a while when running real hard, I will let it drop to 10 PSI. What I am getting at is your motors may be too high causing the excess slip. Perhaps if they were slightly lower you would be turning water that is less disturbed thus getting less slip and higher speeds. Not sure though!
Word of caution, unless you are a motor guru, or have a qualified high perf OMC motor guru in your area, I wouldn't turn stock OMC's any more RPM's than what you are turning. Several buddies of mine routinely damage their OMC equipment trying to run 7,000+ RPM. Good Luck!

HavasuDreamin'
03-25-2002, 01:28 PM
You selling the rig?

WILDMAN
03-25-2002, 05:50 PM
I'm rigging a new 24ft Liberator tunnel this week with 225 HO's. I'm guessing 100-105 mph.I had the OMC rep here, and he said that the limiters just unplug. The only thing that will be affected, will be the idle increase at cold start won't work. You'll just need more choke. He also said these motors will twist 8000 rpm! A few small tricks will get you 275 hp!The 24 is for sale and I've got four 2001 HO's in the boxes for sale for $8995 each-full warrantee. Email liberatorboats@yahoo.com for pics

Skaterfast
03-25-2002, 08:35 PM
Sounds pretty close I think.I run twin 225 promaxs with 34 four blade merc props,1.87 gears at 6500 rpm and get 99 mph give or take 2 mph.

badtrip25
03-26-2002, 07:16 AM
Originally posted by HavasuDreamin':
I am not familiar with set-up on Talon Boats, but the propshaft 2.5 inches above the lowest point on the boat seems high. Most boats run the prop shaft at the same height as the center pod, perhaps slightly higher. How much water pressure are you seeing in your motors? I run my Merc at 12 PSI or better. Every once in a while when running real hard, I will let it drop to 10 PSI. What I am getting at is your motors may be too high causing the excess slip. Perhaps if they were slightly lower you would be turning water that is less disturbed thus getting less slip and higher speeds. Not sure though!
Word of caution, unless you are a motor guru, or have a qualified high perf OMC motor guru in your area, I wouldn't turn stock OMC's any more RPM's than what you are turning. Several buddies of mine routinely damage their OMC equipment trying to run 7,000+ RPM. Good Luck!
thanks again;
my water pressure is ok 35-40 psi

badtrip25
04-02-2002, 06:04 AM
Originally posted by gimprvr:
Hey Badtrip25 how does your boat turn? I hear the Talon has one of the best turning bottoms for a cat on the water. Is this your experience?
Anyone else wish to chime in?
IT IS turning like hell .you cant even sit in your bolsters

gimprvr
04-02-2002, 09:20 AM
Originally posted by badtrip25:
IT IS turning like hell .you cant even sit in your bolsters
Sounds Great!!! I can't wait to get a ride in one or one very similar.

gimprvr
04-02-2002, 09:21 AM
Originally posted by badtrip25:
IT IS turning like hell .you cant even sit in your bolsters
How fast do you feel comfortable turning in this boat?