cloudmaster_321

I'm curious what kind of results I would see with a 3-blade with my set-up. Currently, i'm running a 4-blade 28pitch bravo labbed by b-blades. I'm spinning at 5,150rpm's with a consistent 78mph. Standard 1.5 bravo drive.

I know this boat doesn't need the bow out of the water to go fast, but it does seem like I need a bit more of positive trim that I would expect to see my top speeds. I thought I read, that in theory, the prop would be at it's most effective angle at 0 degrees trim. Obviously, the more boat that is not in the water, the faster, but just thought I read somewhere bow lift in the Eagle was not needed.

I'm not sure what would be done to my current prop to achieve 80mph consistently, or if it's even possible with out more HP.

I'm wondering how my boat would perform with a three blade prop, especially when it's just me and the wife out. So relatively light loads. I think if I knew I was going to have a full boat or towing a skier or such, i'd switch back to the bravo prop. I'm not opposed to making a game day decision on which prop I was going to run depending on what the day was going to bring.

Any insight? Thanks all.

-Ryan

Randy Nielsen

iTrader: (4)

Never heard anyone trying a 3 blade prop on a 250 Eagle. Mine chine walks around 85 to the point of scary & there are quite a few discussions on that though. Randy

bbladesprops

Ryan,

We have found some additional rake angle built into the Bravo 1 propellers helps the Eagle hulls. We know the stepped bottom should run well flat but have seen slight bow lift additions helpful.
We can look up the recipe of your propeller and determine the best options.
3 blade props are not the best route. Especially if your slip is on the high side.

Brett

Eliminated572

The reason your seeing some more gains with a lot of trim is because you are freeing the hull up with the resulting bow lift. Our hulls are very similar just 3' length difference. I have been through 5 props in the past year and have been documenting all results and sharing with BBlades. Even changed lower drive heights trying to find sweet spots. You will gain speed and comfort with Bretts findings with our hullls. The proper amount of rake/cup will allow the hull to free up at lower trim angles resulting in more speed and stability. Granted, every boat is different but I'd like to think you will be a step ahead running with Bretts recipe that we have narrowed down with my testing...Save yourself some time. Also, get yourself some tabs if you haven't done so yet. 80-90 mph in this hull you will quickly come to appreciate the added stability. -Chris

cloudmaster_321

Chris - You happen to have your boat up here on the Madison Lakes a couple of years back for a little get together that I organized?

Are these findings recent? I went digging through my endless records on my boat and found I had my prop labbed back in May of 2010. These changes you guys referring to take place since then?

As far as the tabs, they would be nice. I did get full hydro steering installed last year however. Every year it's a little something, ya know......

From my calculations, it looks like my prop slip is between 13-14%. Not sure if that's a good number or not. Correct me if i'm wrong, but the more trim I need to give to achieve top speed, the higher the slip numbers.

Brett, if you have a chance to call and talk about this I'd be interested to know more. Thanks everyone.

-Ryan
608-712-4194

Eliminated572

Ryan, all our findings occured within the last 2 years so this is recent. Like I said we even moved weight around in the boat with different props aswell. Tried everything to gain data with multiple labbed and standard props. My latest prop from Brett I havent tried yet but I believe we will be very close as the last one was spot on before my drive height change. I went from 8" prop centerline up to 6". Doing so I lost some leverage (thus bowlift) and I ended up needing excessive trim again to gain speed. The shorty did bring me from 86 to 88 but that was with the trim indicator almost buried and shooting one hell of a roost. I sent Brett down another fresh prop and he took the previous recipe and applied some more bow lift. This will hopefully get my trim angle back down to where I was with the previous wheel and standard drive height so shooting for 90 this go around. Yes, full hydraulic steering a must...I couldnt imagine not having it. Let me know if you have any questions or want to chat. Send me a message and I can contact you via phone. -Chris

cloudmaster_321

I'm thinking it may be worth sending my prop back in to get some tweaks. Maybe i'll get that 80 mark after all.......... What do you think Brett......

bbladesprops

Very possibly.
PM me your contact information so I can go back through your file and determine the options.

Thanks'

Brett

cloudmaster_321

Done. Thanks Brett.

Thanks for the tips Chris.