DCB F-29 prop choices

[SummerObsession]

I am picking up my DCB this Friday and I would like to do some prop testing when we get back

Here are the specs:
650 horse naturally aspirated motors (5800 redline, I believe)
IMCO Extreme SC 1.25 drives
Bravo 1 36's will get the speed to 123-125+ (5200 rpm) at Havasu, but acceleration suffers.
Current owner uses 34 pitch Bravo's to get both good acceleration and still run 115 or so, depending on the heat.

What about using 5 or 6 blades?
I have heard good things about Herring 5 blades on an Eliminator, but nothing on a DCB yet. I think the jusry is still out on the 6's.

Any insights?
Thanks

SO

[Throttle Up]

The Hydromotive P5-X would be a great prop for your application. I hav not put a 6B Hydromotive H6 on a DCB yet. So I cannot give you any REAL-LIFE testing info at this time. The H6 is a stern lifting propeller and the P5-X is a bow lifting prop. The P5-X has been producing increases in cruise speeds of 4-8 MPH while still maintaining top end! It truely has been an impressive propeller this year.

Julie

[SummerObsession]

I know the previous owner tried a P5. I don't know if it was the X model or not, he didn't have much luck from what I understand.
When I get the thing back home, I might like to try a set of 32 pitch P5-X's.
Thanks!

[Throttle Up]

Sounds great!

Julie

[Throttle Up]

I have an update on the Hydromotive H6 props. I sold a set to a client with a 29 DCB with twin 900's about 2 weeks ago. He ran the H6 this last weekend and has told us that the props have "Exceeded his expectations" He said that the accleration is phenomenal. His top end numbers increased sustantially! He is extremely happy with the new props.

Julie

[SummerObsession]

GREAT!!!

The Havasu boys have a small pond to boat on, so bottom end and mid range is very important to them.
Since I boat at LOTO, I want to have decent midrange with good top end numbers.
I think either the p5-X or the new H6 would fit the bill well! :mrgreen:

[Throttle Up]

I agree!!!!!!!!


Safe Boating!

Julie

[SummerObsession]

Julie:
It was great visiting with you yesterday. I can't believe someone who lives in Florida knows where Scott City, Kansas is, let alone where my feedyard is!!
Small world!.
I look forward to doing some prop testing and look for good things out of you and your shop!
Thanks again,
John

[Throttle Up]

John,

It was great talking with you as well! I am looking forward to getting you dialed in.

Julie

[SummerObsession]

OK, I finally have some reliable numbers.
5400 Rpm with above set-up yields 116 MPH.
Therefore, according to BAM website, I am getting a theoretical speed of 131 with 11% slip.
While top speed is important, by looking at my run at the shootout, accelaration is also rather high on the list.
What would be the estimated gains with H-6's?
Thanks.

[Throttle Up]

What props for the above was it hte 34P or 36P props. I see you redline at 5800. Were do you want ot run the motors at? I assume at peak HP, to attain the greatest top end.

Julie

[SummerObsession]

Julie, those were stock 32 pitch Bravos.
I'm waiting on dyno sheets as se speak, but 5500-5700 seems to be optimal so far.

[Throttle Up]

With the 6 blade props there would be no comparison with acceleration. The 6 blades make a huge difference compared to the Bravo 1's. I would expect top speed to remain the same or improve a bit with the 6 blade props. Plus all the advantages of multiple blades such as smoothness, better mid range speed, lower plane speed, better planability and of course acceleration.

[SummerObsession]

I think we could actually pitch up a bit and turn the motors a bit tighter. When I finally see a dyno sheet., we'll know for sure.

I'll call you next week.