Veloicty97

I have a new motor in my 1997 260. It has about 625 hp. I was running a 28p bravo but the motor was only turning about 5000 rpm. I tried a lab finished bravo 1 and turned about 5200 at 80 on GPS. I want to try a Hydromotive prop. Wondering on pitch. Maybe 28 or 29 quad 4? I am looking to spin about 5300/5400 rpm...
Thanks,
Kevin

Padraig

Kevin, something seems wrong. 625 hp in a 260 should be turning faster then 5,000rpm. I can spin a 28 Bravo one to 4900 in a 280 Velocity and an almost stock 502 mag. With 625 a 28 pitch should be too small.

Is there a rev limiter on your engine? If so maybe that is the problem.

cp5899

I agree. I have a 98 280 with a blown 509. I was quessing power to be in the 650 range with the small b&m 250 and only 3 psi. That said being said I was turning a stock 30p bravo 1 to 5400. It was still pulling hard at 5400, but I let out because I wasn't comfortable at those speeds yet. My cam is supposed to run best at 56-5800. I'm not familiar with the 260, but I'm sure with 625hp you would be able to over spin the 28p bravo 1. I tried a 28 and it was to small.

captbones

x1. I had the same set up in my 260 turning a bravo 30p like 5500 and getting way better numbers. Something isn't right.

Relaxing

What ratio is in the drive

Veloicty97

The ratio is a 1.5 to 1 bravo with new XR gears and internals. I did not have a rev limiter on it last year when I was experimenting with the props. I am not sure why I struggled with the first Bravo that I tried. I am not sure if anything was done to the prop as it was one of a few props that came with a friends Sunsation Dominator. The boat certainly liked the 30P labbed props all the way through the power. I am usually running with a couple adults and my kid, a cooler, and a half tank of fuel. I notice the boat is sensitive to a couple more passengers and an additional cooler more than I expected as well.
I called the factory and they are recommending a 29p hydro. Wish I could find one to try. The XR shaft limits many available props where I boat

Veloicty97

Well I have tried numerous props. I started with a new 29 P Hydromotive and turned 5000 rpm at 72 mph. I sent that back for a new 27P and not much better. I tried what I thought was a different stock 28P Bravo and pulled 5700 rpm at 76 mph. I tried another razor thin lab bed 30P bravo and turned 5700 rpm as well at 76 on GPS as well. I measured both bravos at just larger than 14.5 diameter vs the Hydromotives at 15.5 and much heavier. Obviously my setup likes the inch smaller diameter much better. Both bravos are not brand new and have been turned down some. I have gotten 79.5 last year with a different 30P bravo but do not have that prop available to me anymore. I was kind of hoping for 83 GPS. I think I have more speed locked up and was just looking for more ideas. Do I try smaller diameter hydro quad 4 labbed?
I do not like all the prop blowout I have been experiencing with both Hydro props I have tried
Thanks,
Kevin

cp5899

I'm assuming your boat will react similar to mine with a 4 blade prop, but my mid range slip numbers are very high. Just the way it is unless you go to a 5 blade, but then you run into drive issues. So I'm told.

I'm not saying anything against your motor or estimated hp numbers, but I think with a true 600-625 you would be in the mid 80's easily. My last blower setup was in the 625-650 range and we hit 88 on GPS and I have a 280. I'm not sure if its much heavier or not.

I'm unfamiliar with how labbed props respond because I've only run stock props up to this point. With my last blower setup I did sin it to 5500 with a stock 30p bravo1. According to Steve and Kenny the hydro props will be 1-2 mph faster at wot, but the bravo 1 won't have any blow outs in the turns which I have found to be true.

Good luck and look forward to what you find as I'm still playing with props myself.