JBravo

I agree! we thought we could break mid 70's with that combo! Its not a true 525hp then! Read my reply below that i added!
Thanx..tomcat!

mopower

Beaks don't weigh much

Gofastboater45

Isnt this really a 26' boat minus the beak & swim platform ? Just diggin at ya thats all.

Dave M

I think the new and old speed numbers you are stating sound low. I would think a 25 Sunsation should do 70 with 365 HP. Maybe there is water in the hull? That could explain the loss of speed since it was bought. 8 yrs. ago? was that before people used GPS speeds? If he truly has 525 HP and only going 70, something is not right.

I have a similar hull and I was running 72-74 with 385 HP. I now have 425 HP and running 76-78. I am turning a 28P Bravo 1 to 5000. So, I gained approx. 1 MPH per 10 HP, and that is at speeds over 70. Some of those "rules of thumb" change a little when talking about boats with a 7' beam.

fund razor

And I can imagine that you spent some serious change, too.

Don't feel too bad Bravo... your buddy can whip my boat's azz and I have twins. (26' with 2 SBCs).

The builder shouldn't have estimated so high. He got your buddy's hopes up.
But I agree with those who say "don't kill the builder, you may need him."
Maybe just mention to him that his formula was a little off.

Formula311-SR1

What does the 25 sunsation weight?
72 GPS with a stock 365 is an amazing number.

That's not a stepped hull right?

I'm happy to be at 70 in an older Formula 242 with a 500 HP (crankshaft) motor.

CFD12

I have a '92 aggressor and it does 75 gps @ around 5200 with a 25p mirage.

Side note: It has a 650 hp. blower motor and I haven't had the balls to hold it out to 6000 rpm where the rev is set

The 454 mag it had did 68 spinning a 23p @5000 rpm

Info only.

BGIII

iTrader: (3)

Did your buddy tell the builder that the boat runs 72 or did he tell him 62? If my boat lost 10 MPH, I be figuring out what the hell was going on. 600 hours on a 454 mag isn't really that outrageous in my opinion. He may want to check some things out with the boat and double check the timing and plugs on the new engine.

Wobble

My first pull on the dyno with a built NA 509 produced 530hp after about 30 pulls and some changes we left it at 581hp as setup for the boat. Best pull lean and added timing was 600.

Point is.. the internal parts were all there to make the hp but dyno time allowed us to make them work. timing, timing curve, jetting, carb spacers, air cleaner design. All these things make a difference to any motor. In my case we found that the 850dp was still pulling too much manifold vacuum at 5600 so we switched the main body out for a proform HP style and picked up 20hp right there+ going back through all the previously mentioned items got us to the final number of 581. this was with the timing backed off to 35 and with the jets rich to be on the safe side.

Most likely you will be leaving power on the table if you don't dyno a built motor IMO

Dyno time cost $450 horsepower found 51....cheap power

cuda

I think what he gained sounds about right. Might want to factor in the hot weather, if it's applicable to your area.