harleyrider

I have twin HP 500's in my 1995 29 fever with 29 pitch props and the best speed I have got out of it is 80 @ 5200 RPM. I have been talking with a guy on Facebook's Passion for Powerboats who has the exact same set up except he is running 26 props and he says his top speed is mid to upper 80's and that the test run from Reggie was 88 MPH in 32 degree weather. Is this possible? Am I over propped? What's you opinions?

Crude Intentions

iTrader: (1)

First off what is your gear ratio? Second what props? Third are you spinning in or out? Also find out all these things from the other guy for a complete comparison. Based on numbers you've given. Assuming a 1.5 ratio that's 16% slip. That can definitely be brought down with prop testing. At 5200 are you on the limiters? Is there more throttle?

MILD THUNDER

iTrader: (3)

If your hitting 5200RPM on stock HP500's, you are not overpropped, pitch wise. Putting 26's on, would do nothing, except put you on the rev limiter, or if limter was removed, probably put you at 5600-5700RPM wide open.

Thinks like prop rotation, prop style, prop depth (x dimension), all may be a factor. Also, take speeds guys claim from the internet, ESPECIALLY some of the morons on Facebook, with a grain of salt. I've seen guys claim 90mph with Hp500's on a straight bottom 38 Top Gun. lol. More like 70 mph. 88mph, in 32 degree air temperature, at sea level, in salt, with a brand new hull, is about as optimum as you can get. Throw that boat in freshwater, 1000ft above sea level, 85 degree humid temps, with some gear on board, and the numbers will drop dramatically.

harleyrider

My gear ratio is 1.5 same as his and I'm spinning in, but what info I got off this site spinning in or out is not going to make over a mph or two difference. I know you have to take what people tell you their boat will do with a grain of salt, that's why I put this here to get some good healthy response. Going to buy new props and trying to get some good info to get best results before I drop the bucks, so I can get what's best for my money. Thank for the help.

Crude Intentions

iTrader: (1)

Check with Brett at bblades for their testing program. You're at 16% slip which can be brought down. Even if you got it down to say 10-11% you'd be 84-85 roughly. I don't think you're that far off.

harleyrider

Thanks I.C.U.

HyFive578

iTrader: (3)

+1 for talking to Brett. He can tell you exactly how to get there and you can get props from him to test and dial in before you fill your garage with props...

29Fever01

Also consider the age or condition of the props, if they are original or have been modified or repaired. I run a 26p bravo 1 on my 29 single which had been the original prop (boat is 01) and I know it had been repaired a couple times for small dings. I bought a brand new one and my performance improved in the mid and too end. Even if they had never had to be repaired consider the stress on the blades after years of use, I'm sure they are not factory specs. Also if you have the reggie report for the boat, it will tell you what props the boat came with if they aren't the same that is currently on the boat, from my own experience with my single, it's tough to beat the performance of the prop it came with unless you have modified the drives or engines.