Driving advice for a 99 Daytona Eliminator 28 TD
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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)
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If drive height is proper you should be able to trim back down to neutral trim at top speed. The RPM will stay the same but the speed will go up because the prop and bullet are more efficient and more in line with the direction of travel. Mine does this now. Last year I was 1 inch above the low point of the hull. I added boxes and went up another inch. With a twin engine boat You should be able to go up higher than a single engine boat. Have you tried 4 blade bravo props?
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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)
With 502 mags my friends 28 TD never broke 90, the guy who bought it put 600 phaffs in it and hit about 112 if I remember correctly. With 572s I would think you shoud be at the same. You should be winding over 6500 and you could go up to 6750 with that motor, I think it is over propped.
28 pitch props at 6750 on a 1.5 drive @ 8% slip = 110
31 pitch props at 6750 on a 1.5 drive @ 8% slip = 122.32 (unrealistic)
Going with a low slip number due to 5 blades...btw I would stick with 5 blades for the stern lift.
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Yes this is the boat from Indiana, I need to confirm drive ratio. Do you really think I should be spinning these gm crate motor 572's over 6500.....?
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This is the 620hp version, not the 720hp version. The specs I looked up for the 620 said peak rpm 6000, and this has a hydraulic roller cam. Was GM really conservative with the numbers?
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The numbers work out to be 108.73 with 31 pitch at 6k so your props might be about right just not sure why you are not turning more RPM. I wonder what your timing is at?
Last edited by JRider; 09-16-2015 at 09:03 AM.
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Super Chevy Mag dyno'd it:
On the ZZ572/620's baseline dyno run, the engine delivered 649.1 lb-ft of torque at 4,800 rpm and 647.9 hp at 5,700 rpm.
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