Gordo

Was your hull blueprinted? If so, any changes to rocker? if so, remind me what your X-dim. is at?
What was the air temp/water temp when testing? (same for each prop test?) What was your fuel load when testing each prop?
What all did you have in the cabin (weight) during each test? What was the attitude of the boat with each prop? (flat or bow-high?) When you said the boat ran "loose" do you mean chine walk? Porpoise?
We'll start with these and go from there...

My Addiction

You better listen to the expert! No kidding. Has anyone gone faster than Gordo in a Tantrum with a stock Hp500?

RedRider69

Howdie Gordo, thanks for the assistance. First off I notice I forgot to mention these tests were with the 1998 Tantrum and not the 1997 Tantrum. I am not aware of the hull being blueprinted, possible, but doubtful. The air/water temp was low 70's at about 3pm was when we started. Started with 20-25gallons of fuel, two adults, nothing extra or unusual on the boat, jackets cooler and some tools up front, anchor some tools etc under the back seat. All the tests were ran concurrent. The boat ran probably what I would call flat to bow high with all props until maybe 4500 rpms, when things seemed to change a bit. The 28 seemed to run bow low for its remaining rpms, the 26 standard ran bow high with a stable ride, the 26 BBlades ran bow high but you could clearly tell more of the boat is outta the water as it chinewalks and kinda feels skittish. I have contacted BBlades and they told me a little about the prop but I have the details elsewhere so I will have to follow up on that part, but basically it has a lil extra lift. I have a nice lil excel chart with speeds etc at the various rpms, I'll see if I can figure out tonight how to make that stuff viewable for ya. Thanks a ton for joining this topic and providing guidance.

RedRider69

OK, here is the missing stuff from my earlier post, lol. BBlades says the prop has "extra trim reaction" and the only other detail I could get is there is room for having less "extra trim reaction" but still being more than stock. I tried to get a reference like on a scale of 1 to 10 but that didn't seem like it was gonna happen, apparently an understandable secret. Basically I'm thinking I want a 28 with more "extra trim reaction" but less than my 26, seems doable so far.

And here are my playin around charts and graphs, all the same data, same day, etc.
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Hey it worked, lol.

My Addiction

You forgot Prop depth. Drive in neutral trim, measure from keel to centerline of prop shaft.

RedRider69

Well the young gal is stacked and packed in a rack until spring so ..... unfortunately additional measurements aint gonna happen any time soon. Dangit lol !

Gordo

Ok, I'm an old guy with bad hearing, limited vision, a brain injury and I'm fat. So you have to help me out here.
I assume "Extra trim reaction" means the amount of bow lift the prop creates?

Griff

I am old and a little fat too and I was not sure what he meant by that either. It probably has some rake added.

RedRider69

LOL, you guys are too much. I was actually hoping someone else know what it meant as the tech wouldn't be any more specific. Maybe I presented the info poorly so let me try again, and I apologize in advance as I am not a word smith. BBlades tech Brad advised me the 26 P prop I have has had "Extra Trim Reaction" added and would not specify anything further. I can tell ya the boat runs more outta the water with the BBlades 26 than my standard 26 as the boat runs noticeably lighter and kinda chine walks a bit and had to be throttled back to avoid exceeding my personally set benchmark of 5200 rpms. I also realize that throttling back is counter productive to max speed, but all out max speed isn't really my goal. My goal is to prop the boat to run 5200 max and have the best cruising speed at 3000 - 3500. In reality I am probably just gonna purchase a stock 28 and see what I get and if it falls short on top probably send it off to BBlades for whatever "Extra Trim Reaction" is and hope I am satisfied with the results. I guess initially I was hopeful someone with a similar setup would be able to confirm a 28 was the best choice but kinda getting the idea that aint gonna happen. I also enjoy playing with excel and turning collected data into a justifiable excuse to buy something, and at this moment it's a prop that I don't need in the first place cuz I have like 5 or 6 already. I probably should post a pic of the boat we are referring since I have 2 now to avoid some possible confusion. Also, thanks so much for helping me with my journey !

RedRider69

Minor puter issue earlier, here's the pics, lol.
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