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partycat
12-30-2003, 05:22 PM
I have a 28 deck boat that I want to perform better. BIG SURPRISE on this board I am sure. I have been around the block in minds eye on increasing performance. It has a 496 HO with the XR drive. The prop is really the first thing I need to work on. I have a 22 and a 24 merc 4 blade. Neither can spin to my redline. Now the top end would be great, but what can I do to get more from the hole shot? Smaller prop or go to a 3 blade. When starting out all I can get the motor to spin is about 3600 to 4000. And no there is not any cavatation. Any suggestions!

twistedpair
12-30-2003, 05:25 PM
Do you have vent holes in your hub? What kind of props?

twistedpair
12-30-2003, 05:27 PM
Originally posted by titties and beer
BLOWN 540:D
Blown Bravo XR:frown:

MRS FLYIN VEE
12-30-2003, 05:30 PM
and a striper pole.. :D

partycat
12-30-2003, 05:32 PM
22 and 24 four blade merc stainless with vents

carreraboat
12-30-2003, 07:26 PM
if you have through hull exhaust the vents do you no good what is the max rpm spinning the 22? if it is close you can have it worked. what is the brand and model of the prop?

partycat
12-31-2003, 10:12 AM
It is a Bravo 1 4 blade stainless. It spins 4500 rpm on the 22.

Windy
12-31-2003, 10:16 AM
Originally posted by titties and beer
HE HAS ONE:D :D :D
Different Party Cat.

Ducatista
12-31-2003, 10:21 AM
I have got a spare Mirage Plus 23p if you want to experiment with a 3 blade....but I doubt thats your answer for your 28 deck. Your hole shot will suck I would bet, but it might help with your top end and higher rpm's. Your welcome to try it if you would like....

Havasu Hangin'
12-31-2003, 10:25 AM
With a boat that big...I'd stay with the 4-blade.
This probably isn't what you want to hear, but I'd try stepping down in pitch. Lower pitch will give you a better holeshot, and bring the RPMs up on the top end.
I think 2" down will bring you up 400 RPMs or so.
What gears are in your drive?

mikev
12-31-2003, 10:35 AM
get the 22 lab finnished this will get you a few hundred rpms and an 1-3 mph.

partycat
12-31-2003, 12:12 PM
I am not sure of the gears. Whatever comes with the XR standard I would assume. I think I will stick with the 4 blade.
Can I get my current 22 lab finished or do I need a new prop? If a new prop is needed then any recomendations.

partycat
12-31-2003, 12:13 PM
Sorry about the confusion in the screen name. I have had it for a while and the wife wont let me change it.

Havasu Hangin'
12-31-2003, 12:28 PM
Originally posted by partycat
I am not sure of the gears. Whatever comes with the XR standard I would assume.
If you have the standard 1.5 gears...then I'm gonna assume you get about 55 MPH on the top end? Is that close?
Originally posted by partycat
Can I get my current 22 lab finished or do I need a new prop? If a new prop is needed then any recomendations.
You can get your current prop lab finished. Labbing will thin the blades and blueprint the pitch on all the blades...making the prop more efficient. I think it's a couple hundred bucks, depending on whether Merc does it or not. Labbing is a good investment if your gonna keep the prop.
However, I'm not sure that'll help your holeshot like you want.
I'd look for a 20" 4-blade to try out. If that works, maybe you can have some pitch taken out of your 22". Also, maybe you can have some diameter taken off your 22"...which will loosen it up out of the hole.
Try to find a shop that will work with you on the changes and/or demos- maybe even trade that 24" in. They usually know what changes are needed, and whether a new prop will work best.
BTW- if you can spin a 20" to 5,000 RPMs, then you should have the same top-end speed you have now, but I'll bet the holeshot is much improved.
PS- I'd change the screenname...I wouldn't want to be associated with that other guy.

mikev
12-31-2003, 01:49 PM
check out this site you can put vent holes in your prop to increase holeshot for nothing. if you are running thru hull exhaust it wont do any good though.
prop vent holes (http://www.marinemechanic.com/site/page76.html)