Thats money well spent!!!:cool:

It really is, and without alot of B.S.:cool:

Ran boat today
 

Did 1500 RPM bores out of my skull- I bought a used hydro-hoist and spent 2.5 hours towing it by water to my marina!! that sucked but the hoist is nice- Real pain in the butt..

Cosmic I think you are doughting my #'s-I thought a 525 is under rated so most likely it is 540hp

I don't dought your #s at all,I think it is great that you can pick up that much speed that easely. And I know the boat will take it and more. I am very happy for you .:cool:

I can vouch for the 10 MPH increase. I swapped my 502/415 for a 525 EFI last fall and saw the same increase in a 26' Sonic Prowler. I actually saw an 11 MPH increase and I'm still not done with props! Steve

26 sonic
 

I had a deal fall through on a 26 prowler which led to my A/T 525 is a nice engine for the 26-boat must move!

509, what speeds are you getting and does the screen name mean that you have a supercharged 509 in the boat now? So...what is the actual HP of a 525? 500 or 525 or....

So if I was going to build a new bullet for my 25 AT and it runs 70 now.......with a 415 w/gil exhaust and a K&N filter, its all in the X and the prop, if I get 500-525 HP I can run close to if not 80?:cool: :D

R I would think you would be getting there or more. Can you say LITE!!!!! I can't imagine there would be much of the hull in the water at those speeds, you might want to think about longer tabs:evilb:

That would be nice haven a 525 in my tantrum.......maybe if I ever sell the stingray I could go blue:cool:

Cos, I'm doing an external hydraulic steering this year and finish it off next year with the full to the helm. I've always toyed with the idea of building a nice 500 horse motor for the Tantrum. The 1st Tantrum we saw was the Smith Bros. Racing Tantrum and it had a HP500 carbed motor in it. It ran high seventies to a low 80 depending on conditions....It had a full cabin sans the sink like mine. So I'm figureing......500-525HP....80mph!!

And about the tabs....I have the wide K-planes...and you know what they say....."If your not running on the edge, your taking up too much space":D

LOL:D

525
 

525 in tantrum got to be 80?

Guessing about that , if it gets +10 mph in a 28 might be more in a 25 cause it's lighter, not sure on my top speed yet with 502mag no gps yet, guessing 67- 68

Tantrum had apretty stout motor in his......not sure of the speed. He sold it to a guy in Kentucky and he says it runs over 80. :cool:

I had a 560hp dyno in my 24 pantera, which may be heavier than a tantrum. I had it up to 75. Current owner has it up around 78-79.
A 525 is rated 525hp at the prop i believe, you'd be 80+ w/ that in a 25AT.:cool:

Then again... see the thread... by chaos.
"25 active thunder for sale lacated in RI 1998 25 ft Tantrum, fresh water boat and always garaged, 35 hrs on the motor, custom paint, 572 Dart w/canfield salt water series heads dynode @, 672 hp, 679 ft. lbs. torque @ 5200 RPM, Bravo 1 out drive, 30 pitch Bravo 1 prop, Stellings extension box, Mayfair duel ram hydraulic to helm external steering, 380-series K-planes"
... 82mph. hmmmmm.

Spoke w/ throttle up
 

I am going to send them my prop-they said max. Hp is at 5380 RPM so I am off by 280 RPM-labbing will give me this-just now to find the time to ship prop and wait. I am still debating if it is even worth it?? 400.00 to lab beach the boat and nick the prop??? How much more speed will 300 rpm's actually net me?

risky, i think its more about running the engine in its proper powerband, than the speed you're getting out of it.
I'd 1st try some props before re-labbing yours.

2-4mph...If you lab, you need to budget about $200 a year per lab for prop to maintenance. It is about running in the correct power ban. Less load longer engine life....I would also invest in a back up prop.

2-4 mph gets me 75-78 mph that is worth it. I was talking to a prop shop today and they need to see my prop to see what they can do..thanks for the help