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-   -   The test drive=100MPH (https://www.offshoreonly.com/forums/fountain/209201-test-drive%3D100mph.html)

1 MAIDEN AMERICA 05-19-2009 10:44 PM

The test drive=100MPH now 102MPH
 
See "take a guess" for more info. Basically 02 38 Lightning, 700's, -1 IMCO's, 6bl 15.5" 20degree 35P Herings, 5350RPM, 100MPH GPS.
Want a little more!!! Sound like my wife.
What next?

gerritm 05-20-2009 07:57 AM

Congrats. You always want more. Most of us could have named our boats "Never Satisfied"

1 MAIDEN AMERICA 05-20-2009 08:48 AM

My first boat was "NAUTI NUFF". There was also a stripe by the second N making it appear as an M.
1993 27 Mirage Intimidator T502Mags.

aTX427 05-20-2009 09:06 AM

Turn up the boost and the rev limiters. 575's should be able to handle 5,750 without floating the valves. 6,000 if you go with better lifters and springs. Can't remember what you have for uppers, but I see a set of B-Max's in your future as well.

1 MAIDEN AMERICA 05-28-2009 01:22 AM

Trimmed the innercooler PU's, people (3), gas (60gal) and contoured the leading edge of the IMCO skeg. 102MPH on the limiter (5350). The boat is usually faster full of fuel so I'll try again this weekend.

monstaaa 05-28-2009 11:50 AM

what ratio are you running? sounds like you have a highslip #.

1 MAIDEN AMERICA 05-28-2009 11:26 PM

1.5:1. Slip used to be around 12% with any prop I used. Now with the shorty and Hering its at 16%. ??? Why would the boat be faster with more fuel on board? I'll try this weekend with the new setup and full tanks to see if low fuel sped me up or the trimming and contouring. Drives are toed in about 1/32" props spinnin in

1 MAIDEN AMERICA 05-30-2009 02:57 AM

Full tanks, 4 people, warmer day, rougher water = 101MPH and not on limiter, but close, so...fuel doesn't matter now? Definately harder to get on plane. Hering said cupping the prop should help without sacrificing speed.
Because I'm only running a -1 lower, do you think a 5 blade prop may top out better?

RaggedEdge 05-30-2009 06:56 AM


Originally Posted by 1 MAIDEN AMERICA (Post 2875431)
Why would the boat be faster with more fuel on board?



Goes against all the basics, but seems like in some rare cases it does happen. My 35 does this as well. With the 5 blades stock the boat came on plane fairly well and full fuel would take away 1 or 2 mph, normal deal. After the lab work it was a chore to get it on plane and would run a couple faster with full fuel and extra people, the more weight in the boat the faster it ran. The slip number would go down with the extra weight, not the normal deal at all. In my case the extra weight also made it easier to get on plane.

My thought based on the way the boat felt, and the weight deal, was that there was too much tail lift resulting in the boat being pushed up and losing bite. Sent them back again for another tweek, change the blade rake to get rid of some tail lift in favor of more bow lift and have a little more cup worked in.

First run, this past monday, resulted in the boat coming on plane respectably, and being a couple faster than prior to these last tweeks. I started with about 3/4's fuel and two on board, losing fuel did not slow the boat this time. One afternoon is not enough to make a real conclusion on the deal but it seems to be headed in the right direction, maybe. I'm still down a couple hundred revs and if I can get them back it should run faster than the old best number.

My boat does plane better still with the 4 blades than the 5's, the cup change has helped. Maybe some more cup would help you as well, or a change to 5's vs the 6 blades might work out better. The slip increase could be the result of the extra tail lift created by the 6 blades. This prop chit is a PIA, it seems the more you think you have it figured out the more you find that you don't. It will be interesting to see how you make out, keep us posted.

1 MAIDEN AMERICA 05-31-2009 01:21 AM

I'm wondering if I still have too much prop in the water for the 6 blade. Every blade is friction. I also don't throw any roost. Does thet tell anyone anything?Thanks for the input.


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