shawn

What props do you guys run on your 36s? I have run P5s 30 and 31s. My motors make more power at higher RPMs now, so I would like to spin my motors 6,000 or so and was wondering what prop help I can get.

Thanks in advance
Shawn

jbrauer

I've recently purchased a 2003 36' with 650's and put about 10 hours on it before winter. With stock 34" Bravos I saw 117 at about 5800 RPM. I now have a set of labbed 36" Bravos and am looking for some labbed 34" Bravos. The boat was delivered new with labbed 34" Bravos and an 120 @ 6,000 RPM. We'll see in a couple months!!

What power and outdrives are you running with the P5's?

shawn

Mine is a 1999 and its been modified to match Zip Express. The drives were moved up about 1.75" and in, but I do not know how much. Yes, the transom was redone. I have HP500s with a little work, about 580HP, but the power band moved way up and there is little power down low. The motors will run like raped apes to over 6,000 and pull after 5,000. The engines were done by strip guys and I think they took too much out of the heads and I lost flow velocity.( I developed this opinion is from reading Teague on Powerboat mag). Short version, I like the 5 blades and have seen 110 as best top end. Two people, low fuel blah blah. I do not think my boat has much more than 110 - 115 with everything at its limit. I don't care as much about the last few MPH as I do the all day driving of the boat. The Five blades are smooth and I had REAL problems getting my boat on plane with the Bravos. They just kept cavitating and I am just not good enough to feather them with my motors.
I think I may need to move to a set of five blade 29s and let them spool up. This will cost me in the cruise, so I need to really do a little homework and learn what is the best all around prop.
Did MDG build your motors? I love the boat and dollar for dollar, you can't beat the Spectres.

I run 1.36 XRs and have a pair of XZs as spares. I have used the spares more often than I would like, but that's boating in the Chesapeake Bay. Glad I own them.
Where do you boat?

Thanks
Shawn

jbrauer

Yeah, they're MDG 650's and seem great so far. They idle fantastic and don't seem to load up regardless how long I have to idle. Power is strong from idle all the way to top end. MDG says they can spin to 6,000+ with no problem.

My boat comes on plane with almost no bow rise and no cavitation. I just have to bring on the power very smoothly. I may try some 5-blades in the future, but I've heard bad things about blowing the XR's with them due to too much bite. On the other hand I've heard 5 blades reduce vibrations that can hurt the XR's. Who knows???

I'm in Nashville, TN and boat on various reservoirs on the Cumberland and Tennessee Rivers.

I agree that Spectre can't be beat for the price. I bought my boat from a guy in New Jersey and picked it up at Pro-Roc Marine. It was originally tested in the Powerboat magazine Speed Issue in 2004.

I love it so far!

shawn

That may have been Jay's personal boat. I have not had any problems running five blades, I ran them on my 30 Soectre also. Very smooth and no problem getting on plane. I have had Craig Collabello go through my drives when needed, he does a lot of the race drives and is a good guy with whom to work. He has replaced a few gears for my, he calls it shedding when small pieces start to come off the gears. I do not know the cause, he said they "just do that".

Boater8987

Hey Guys glad to Here someone other than me has been doing R&D tests on the drives and ratios for the 36. Please call me with imfo I can inform you of my results. 36' with 575SCI= best of 129.8 with xr standard LWP only case and hydromotive nose cone. And Arizona boost kit.. Tested sportmaster lower and created loss of speed with sportmaster case but is stronger. I have played with spacers and have a set of 1.5" with 1 hr run time for sportmaster avalible. 36Px1.26 ratio. Hey 4 blade bravo's are the best. Merc knows their chit. Gary 703-477-9071

jbrauer

You're right.

jbrauer

Wow - 129.8!! That's fantastic! With the Arizona kit how much HP do you think you're making? I'll be running 34" or 36" props through 1.36 gears at about 120.

What's you're secret set-up?

Boater8987

Arizona claims 60-80 hp. Kit = smaller top pully-120 degree thermostat, MSD 6M Box and reprogram the ECU. Maybe 50 real HP at prop. With 36p bravos and 1.25 gears, with merc LPW xr lowers and cones put on at Spectre. This is also a MDG boat and was picked up at Pro-Roc. You can read about my prop testing in the Lower unit and drive section. Sportmaster = Lost MPH? No secrets here. It takes forever and a few miles to get going. I will be going back to 1.36 gears this year, for better all around performance.

shawn

You guys have some good numbers with those Bravo props. It does look like the slip numbers are pretty high. I need to reprop and get more RPMS since the new motors make power at higher RPMS, just don't know what to use. I tried 34 Bravo four blades and had a terrible time getting on plane. Is there a trick I never learned?
When I did get on plane it felt like it was running nose high, compared with the P5s, they felt flatter, I guess more stern lift.