I just finished testing a new prop. Prop pitch vs prop diameter.
I've been trying to find the right prop for my straight bottom 270 since I bought it a few years ago.
I main complaint all along has been that the boat runs wet, and wouldn't carry the bow. The boat is super stable, but slower than is expect because it runs so wet.
I started with Bravo I's, and they sucked big for me. They would blow out bad getting on plane and also in turns at slow speed.
I tried a P5X next, and that was ok, but slipped a lot.
After the Bravo I and P5X, I tried a CE 5 blade 30p and 32p. Both worked well, but I wanted more rpm on top. They came out great, and held nicely in turns. These props were great for cruising.
I also tried a CE 28p 5 blade and that worked for crap. I'm not sure why the 28p sucked so bad compared to the 30p, but it was not a good match for my boat. The 28p kept the nose buried and blew out a lot. It also did not respond to trim. You could trim up, and get more rpm, but the bow would just stay buried.
I also have a 30p Maximus 15" diameter. This ran very similar to the CE 30p, but cruises a about 3-4mph slower. I think this is because of the smaller diameter.
I keep complaining to Josh at TCM about how I feel like I just don't have the boat dialed in correctly. He always says to run a Maximus, but I told him I didn't notice a difference between it and the other props I've tried. Josh told me to leave it with him and they would work it out.
So... last week I dropped the boat off at TCM and told him to it out.
Turns out that Bob ended up taking it to the lake to test the props. First of all, I gotta say that it's damn cool that Bob took the time to play around with my tub!!!
He ran it first with the CE 28. He said it was terrible! Basically the same thing I already mentioned about blowing out, and burying the nose. He then grabbed a Maximus 30p 15 1/4" dia and ran that. Way better! It came out great and carried the bow, but He wanted a bit more RPM on top. He headed back to the shop and grabbed a Maximus 28p 15 1/4" with a cut diffuser ring. After running the 28p, He came back with a smile and said that's the one. He said cruise went up almost 10mph and top speed improved by 3-4mph with 200rpm more on top.
We were at Mohave last weekend and I can back up his results. It comes on plane quicker, pulls tubes easier, and idles in the no wake better too. With the bigger pitch props, my no wake/idle speed was about 10mph because of the 1.50 lower. Now I'm at 7mph. The other thing about this new prop is that it carries the bow much better. I can actually get it to chine if I trim up at speed. Before, the trim didn't do much.
I am still surprised how much of a difference 1/4" makes. I would have argued that a 28p wouldn't work, based on past experience, but this is my favorite prop now.
Has anyone else had similar results?
Thanks again Josh and Bob!!!
I just finished testing a new prop. Prop pitch vs prop diameter.
Great information Skav!
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