What's Your Best Guess....??
 

So I'm getting ready to do some prop swaps/testing and I'm curious to see what everyone thinks the end result will be.

The original #'s/specs are as follows;

2008 Heat/710 ILMOR, IMCO Extreme 1.50

Sea Level, 50 Gallons, (2) people, stock 26 bravo one, the boat ran 89-90 @ 5850rmp in 3 foot chop and 30mph wind.

2200 above sea level, 70 gallons, (3) people, same prop, flat sticky water the boat ran 84-85 @ 5500rpm.

Rev limiter is 6300.........
I have (3) bravo one props to test;

labbed 26.

labbed 24 with a cut diffuser.

labbed 24 reduced diameter
14 3/4".

What are you guys/gals thinking in terms of gains/losses per prop?

Best Guess
 

YOUR stateing what you came up with BUT water and conditions not the same, what are you looking for hole shots,mid range & top end, once you find out what your after send a e-mail to julie[ [email protected]] or brett [Bblades.com] -920 295 4435 ] [ julies # 727 531 2255 ] give them all numbers off your dyno sheet if you still have them and what your trying to get your boat and motor to do , my best W.A.G is go with the 28p lab and call the above people and it could be tweek alittle more, " GOOD LUCK ! " :cool-smiley-011::evilb:

I should clarify...............
The props that I'm getting ready to test will be at 2200 asl.

Tony,

Thanx for the question/answer. I've talked with Brett and I hate to tell you......... the 28 isn't even in the picture.

naturally asperated will lose 2% per thousand feet, so at sea level I would say a 26P labbed would get you close to the limiter, with a little help from bret or julie, at 2200 ft, your going to be looking at the 24P labbed prop, the cut down 24 prop may work also, your in a trial and error position. Good Luck. just a little info: buddy has a heat with blown 900hp engine, at lake powell, 3700ft asl he runs a 28P B1 stock 83-86 gps'd. Altitude is a killer on N/A engine's
Larry

I just ran the # for your set-up, 5850 rpm, 26P, 1.50:1, 90 mph, and the other # also, it comes out to 6% slip, that's pretty good numbers, almost to good for a heavy deep V hull, is the speed gps'd, is the tach right? If the # are accurate, you should run about 85-87 with a 24P prop. at 6100 rpm.
they say B1 prop's acual pitch is 1" smaller than they claim, if you use those # it is 2.5% slip???????

I think that you are fu$ked and the boat is only good for about 75 tops!!!! That means i will get you by about 1 to 2 mph. Just enought to get passed you. :D did you ever get a chance to try the new props??? Long is down 3 feet and you have to go to the end of the lake to get on. I bet you are ready to die with all this water and not able to run with the sweet new Nordic. Hey if your around on Sat I'm having a big B-day party at my house and you are more than welcome to join call me if you want to stop by. we are going to kill at least one keg! Good luck with the testing keep me posted. TRY NOT TO KILL ME TOOOOOO BAD!!!!!!!!!