Setback effect on Blowout speed?

[aaronmt]

Not a Allison question but trying to get others ideas on it.

On our 98 Velocity im running 10"s of setback and still feel I need to run more positive trim then I should.Ive seen 83.5 and believe there is a bit left but also know im nearing the blowout speed of the Torquemaster.I ran it with 12"s with a previous motor and know its good for a bit of speed since its carrying the bow easier.The question I have is does going back raise the blowout speed of the lower or make it more likely to blowout at a lower speed.The boat isn't fastest enough to go to a sporty simply because its not a 85mph boat everyday and we mostly run in the 60-70mph range.It seems to me it would be cleaner water back a bit more therefore better water,but im not sure.Thanks for your thoughts and input,Aaron

 

[TBuck2003]

Not a Allison question but trying to get others ideas on it.

On our 98 Velocity im running 10"s of setback and still feel I need to run more positive trim then I should.Ive seen 83.5 and believe there is a bit left but also know im nearing the blowout speed of the Torquemaster.I ran it with 12"s with a previous motor and know its good for a bit of speed since its carrying the bow easier.The question I have is does going back raise the blowout speed of the lower or make it more likely to blowout at a lower speed.The boat isn't fastest enough to go to a sporty simply because its not a 85mph boat everyday and we mostly run in the 60-70mph range.It seems to me it would be cleaner water back a bit more therefore better water,but im not sure.Thanks for your thoughts and input,Aaron

You will be LESS likely to blow out because the motor will be lower in the water back 2" and the prop sees cleaner water the further back ya go ...

 

[aaronmt]

Thanks Todd,I was thinking the same way.Brian and I were on the fence though..I've heard a wide variances of tqmaster blowout speeds.some say up to 87 some 84,any thing I can do to improve it slightly without a cone?I imagine some would blueprint it but I'm in sure how to exactly go about it.

 

[whipper]

Do you plan on putting a SM or Cone on Aaron? Wouldnt you be able to gain speed running higher ?

 

[TBuck2003]

Thanks Todd,I was thinking the same way.Brian and I were on the fence though..I've heard a wide variances of tqmaster blowout speeds.some say up to 87 some 84,any thing I can do to improve it slightly without a cone?I imagine some would blueprint it but I'm in sure how to exactly go about it.

I would plug up 4 water inlet channels on each side of gearcase to improve water flow back to prop. This will help flow and help PSI. If you can run higher you increase your chance to NOT blow out with less case in the water to affect aspect ratio of lower unit... NICE BOAT !!!!!

 

[aaronmt]

Id go to a sporty if the boat ran over 85 consitantly.Ive got 5 of the 8 holes blocked off it has 4 holes in the nose.Im thinking im going to go back to 12.5"s raise it one hole and plug another hole on the side inlets.....then let-er eat lol

 

[whipper]

I didnt relize they had holes out front also thats cool. Havent look at to many non coned ones for years. What you said makes sense about what holes to cover for water pressure and running higher.
A buddy im boating with next week has a 22 Velocity. Nice looking boat on the water. He has a 502 in his though. Kinda heavy for speed. i think he can do 70 maybe? I know im doing 60 by the time he plains off with that BB in there.:very happy A setup like yours would be the way to go.:beer:

 

[John Richied]

Aaron if you want to go faster

 

[aaronmt]

Aaron if you want to go faster