Sizing a ACME Prop with Permanent Ballast

[boneil]

Lesman put me onto something today...  Bill Weeks at ACME is helping me through getting a new ACME prop.  Today he said, "just get an ACME on it and we will swap until we find the right one."  30 day money back guarantee! 

I need this site's guru advice to know when I've found the right ACME prop.

My requirements
1.  Hole Shot, Hole Shot, Hole Shot

My current specs
-13x13, 4 blade bronze, LH, 0.08 cup, 1 1/8 drive shaft diameter, 1 to 1.22 gear ratio (If memory serves current prop has "Johns(t)on" and "Legend" stamped between the blades
-WOT RPM 5500 and 40.1mph per GPS (Just improved to these levels with Only Chevron, plugs and MAF cleaning... Feels like the day I bought it new!)  Never attempted red line before, but never came close either.

What Bill at ACME recommends (515 or 541 depending on shaft diameter)
13x11.?, NiBrAl, LH 0.08, 1 1/8
"Will improve hole shot, sustain speed, better gas mileage & prob 2 to 3 mph on the top end"
He also recommends synthetic Mobil Purple for oil and trans to get more rpm

What I just remembered (I'm a dumbass and thanks to Lesman) is that I run with 300 Lbs of lead shot in the very bow of my Toy.... Let's assume this is the cause for 200 to 500 rpm less than redline and 1-2 mph on the top end.  Let's also assume that I take Bill @ ACME up on his offer and try 3 different ACME props incrementing the "pitch" (I believe) until I'm back at 13X13.

Given that I'm going to run with lead in the bow... Have for so long that I don't even notice anymore and I feel this boat was meant to have at least another 150lbs more in the bow....  what "output variables" should I use to make the final prop size decision!?  Or is the lower pitch going to give me what I need and going back to 13 will only improve top end.  Or do I hunker down pay the freight and go through the ACME "buffet of sizes." 

Good problem to have... just curious that if I love the prop that arrives Thursday and it gets me closer to or over redline that i wouldn't have left some additional performance on the table if I didn't try the others. 

PS I love this boat!  If anyone is going to be on lake Norris this weekend let me know....

[lesman01]

I can tell you I have the 525 and carry no ballast as of now. Hole shot is better than stock, but I honestly could not tell as much a difference as I expected to feel out of the pocket. I had a stock 3 blade OJ I think..A fouled plug could have been the reason I did not see a big difference in low end. I love the prop! it is silky smooth through the whole rpm band.

So, I may be wrong, but if he's telling you to go with 515 13x12 pitch, that would theoretically give a worse hole shot than my 525 13x11.5 pitch? I hit about 5700 RPMs with the 525.

I too, talked to someone at ACME to figure out which one to use, and he suggested the 525 as I said i'd carry about a grand of ballast (thinking ahead)

Not sure what to tell you, but seems like if all you want is a better hole shot, go with less pitch.

I may very well not know what I'm talking about, but sure I'll get set straight by one of the true gurus.

This url gives them all side by side:

http://www.tacomapropeller.com/product.asp?Product_Id=176020&d_Id=17417&l1=17417&l2=


Photo     SKU      Diameter / Pitch / Rotation / Blades / Bore Size / Cup     Price     
     
     Acme-515    13 / 12 / LH / 3 / 1-1/8" / .080    $398.00    Add to Cart
     Acme-525    13 / 11.5 / LH / 3 / 1-1/8" / .080    $398.00    Add to Cart
     Acme-541    13 / 12 / LH / 3 / 1" / .080    $398.00    Add to Cart

[wakejunky]

[toyotafreak]

A boat is normally considered properly pitched when you floor it and it ends up at redline. You might not ever run that fast, but you should if you're asked for your Wide Open Throttle RPM. Mine seems to be a bit less than 5500 nowadays. I'm not sure if the >100F ambient temperature plus my ginormous bimini are enough to explain the lost300 or so RPM over what I remember getting back in the day. This tells me that for my typical summer activity, we're over-propped. We have been cruising a bit more at higher speeds than before (30 is fast for me when I'm cruising over 20-30 miles upriver and back in a day). I'm sure getting that 500 rpm back would help a lot with the hole shot, and would cost a bit in fuel.

If we really wakeboarded heavy often, it'd be very important to get a new prop. I've had 3K in my boat before and a proper pitch for that setup would be something way shorter than my 13x13 4-blade OJ SS. Mine's the 1.2:1 ratio, btw.

Bone, I keep a similar amount of weight in the nose. I don't think that'd cost you even 50 rpm or 1 mph in top end. Could be wrong (witness my missing 300-500 rpm).

[boneil]

Great stuff all!  I'll see what's in the box b/c Bills spec aren't matching up with his model numbers.  Should either a 11.5 or 12.  And I paid more than the website you provided les!   

thanks for input on the assumption of perm. ballast.  I feel much better that I could likely be over prop'd for what I want to do with my current 13x13.

Curious if anyone out there is getting 6k actual with a vdrive and 13x13 0.08 cup

[PSullivan3]

I get 6k but thats with the 1.41 gear in it, also with people ballast est 1400-1500 lbs no problem