Driving advice for a 99 Daytona Eliminator 28 TD
09-16-2015, 09:45 PM
#21
My boat at 1 inch above the bottom hated a 5 blade Maximus prop. It created so much transom lift that I couldn't get it to pack air. I even cut the flare off of the back of my Bravo 28 - 4 blade to reduce transom lift and the boat loved it. It settled the rear and the handling increased. It drove like it was on rails.
09-17-2015, 05:53 AM
#22
My boat at 1 inch above the bottom hated a 5 blade Maximus prop. It created so much transom lift that I couldn't get it to pack air. I even cut the flare off of the back of my Bravo 28 - 4 blade to reduce transom lift and the boat loved it. It settled the rear and the handling increased. It drove like it was on rails.
One thing I remember about the 28 daytona is that it seemed substantially faster when he ran the fuel down below half tanks. It felt like a different boat, he always filled it all the way up and it held a lot of fuel.
09-17-2015, 07:40 AM
#23
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Okay went out to the shop last night and got some more details on my setup. The props are 15 inch diameter Hydromotive P-5X 31P 5 blade, and my drives are the older Imco Extreme Advantage with stock looking lowers (not the Imco speedmaster style). I could not find gear ratio, or serial numbers stamped anywhere on the drives, so I pulled both top caps and low and behold 29 tooth upper gear!! This makes them 1.36 ratio's if I have done my research correctly, and I was surprised as I assumed they would have been 1.50's.
09-17-2015, 07:44 AM
#24
If it is an XR type upper, I believe the gear ratio change is in the lower and all the upper gears are the same.
If it is in fact a 1.36 that would put your slip at 15% (using your original post numbers) which is quite high for a cat.
From what I have read, the hydromotive props are more true in pitch than bravos/mercs. For example, a 27 hydromotive runs somewhat like a 28 bravo, some of that might have to do with the hydros diameter being larger. I would think that would hold true for the 5 blades as well
If it is in fact a 1.36 that would put your slip at 15% (using your original post numbers) which is quite high for a cat.
From what I have read, the hydromotive props are more true in pitch than bravos/mercs. For example, a 27 hydromotive runs somewhat like a 28 bravo, some of that might have to do with the hydros diameter being larger. I would think that would hold true for the 5 blades as well
Last edited by JRider; 09-17-2015 at 07:54 AM.
09-17-2015, 07:56 AM
#25
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The upper gears are not straight cut, I don't they are the xr style. I think I was over trimming trying to get rpm's, which may account for the high slip numbers. If the drives should be trimmed closer to neutral rather then lots of positive trim, I think I may need less prop to get my rpm's up, and speed numbers higher???
09-17-2015, 05:55 PM
#27
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Hello all, I have just recently purchased a 99 28TD Daytona. The boat has twin 572 natural aspirated motors making 625hp, imco drives with standard lowers and 31p 5 blade props turning in. X dimension is even with the bottom of the boat, and no boxes. Only had the boat out 3 or 4 times, and have only made a handful of top end runs but I have only seen 97 on GPS so far.... this was at about 5200-5300 rpm's and trimmed out decently well. Looking for some driving tips on this hull, or set up changes. I have had cats in the past, and everything I have read and discussed regarding this setup I thought I would be up in the 110-115 mph range. Thinking I need to go with the imco -2 lowers to get some speed back? What does everyone think? Thanks in advance for any input. (as I understand it 496HO boats are breaking 100)
09-17-2015, 07:22 PM
#28
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I had a 2002 28 Daytona TD, with twin 496 mags (375hp each). The p5x's are the best props for that boat. My best top speed was 90.7 on a cold day with a very light boat, but it would run 88 consistently. Your top speed is way off, you should be around 115. I had 29" p5x's on mine. In terms of where to trim for top end you can see the bow come up and down with the trim you really don't need a ton of trim to get top speed. Also be careful turning the boat will spinout if you let it, fun at low speeds but no good going fast. You can feel it start to rotate if you turn to sharply. My drive setup was the same as yours, but with XZ drives. My props were also turning in.
09-21-2015, 03:15 PM
#29
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Checked timing yesterday, I have 22 degrees initial timing and 50 degrees advanced timing!!!!!!! Holy smokes that's way to much advance. Checked both sides, same on both. Stock GM hei dizzy's, ATI fluid dampeners with timing marks stamped all the way around, and a standard non adjustable timing light. Motors run perfect, and can't believe they are even still alive running this much timing for two full seasons.
09-21-2015, 04:14 PM
#30
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Rob,
For sure trim down after the boat gets on plane and flat. with these boats you need to trim up to get them on plane and to start packing air then back down. Usually at 60-70mph or so you should start to trim back down. Its counter intuitive but its really does make a difference. over 80 your roost should be pretty small. look at some youtube videos of the shoot outs with Cats at LOTO. You will see them trim up then back down.
And I agree the Tres class would be great to do.
Great Boat BTW.
MP
For sure trim down after the boat gets on plane and flat. with these boats you need to trim up to get them on plane and to start packing air then back down. Usually at 60-70mph or so you should start to trim back down. Its counter intuitive but its really does make a difference. over 80 your roost should be pretty small. look at some youtube videos of the shoot outs with Cats at LOTO. You will see them trim up then back down.
And I agree the Tres class would be great to do.
Great Boat BTW.
MP
