supercharged 25 outlaw prop size ?
#11
the Flightmaster
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Well who ever said you canīt get Baja hulls to run fast? 90+ mph out of 750 hp in a 5000 pound boat is pretty damned respectable, Iīd say.
those are two really hot 25 Outlaws!
Tony, did you have the fuel pickup modified. The Whipple build manual for a 525 Motor describes the fuel flow requirement as being way above what the standard pickup on a 25 OL can deliver. 7/16" instead of the standard 1/4" inside diameter, if I remember right.
A major fuel flow restriction is a motor killer, particularly on a blower motor, but even a slight restriction will kill top end power, and speed.
those are two really hot 25 Outlaws!
Tony, did you have the fuel pickup modified. The Whipple build manual for a 525 Motor describes the fuel flow requirement as being way above what the standard pickup on a 25 OL can deliver. 7/16" instead of the standard 1/4" inside diameter, if I remember right.
A major fuel flow restriction is a motor killer, particularly on a blower motor, but even a slight restriction will kill top end power, and speed.
#12
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i had all new lines run from the tank remove check valve and replaced fitting on tank to the biggest size that would fit ran teflon ss braided line to new teague fuelfilter mount bolted all the way down on the firewall behind the seat ran 10 an ss lines to magnaflow 500 pump mounted of the side off the platform in the bilge then ran 10an line to the transom and up the back to a aeromotive fuelpressure reg with a bypass return and two seperate feeds one to each hard line for carb blower. if i am not mistaken whipples need all new fuel lines and assembly and filter housing never installed one but have inquired to some degree. you have to remove the the one way valve it is very restrictive.
#13
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Tony,what size types of props do you have any of them labbed,i see you cut the underside of your hatch to fit the 420 under there how did you get any air to the engine with the breather being recessed inside there and could you still lay on the cover you no how the wives like to tan.
#14
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At 5100 rpms,1.50 ratio drive,28 pitch merc either your drive ratio is incorrect and is a 1.36,your prop is a couple sizes bigger then its marked or your speed is actually slower (was it gps or speedo) because your numbers don't add up. I would expect your slip to be at least 15% if not higher and your top speed would be 76.6 MPH at 5100/15% and most set-ups like yours end up closer to 20% slip. See if you can figure out which one is incorrect and we'll try to help,Smitty
#15
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PS-on one of my old set-ups I used to turn a std 28 pitch merc 5200 in my baja at 79 mph w/1.50 ratio drive,I added more boost and could turn a 30 pitch labbed about the same rpm and saw 82 ish,just to give you a relative comparison.
#16
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stock speedo with low water pickup heres the numbers with a non labbed 28 bravo blade.
32 mph @ 2600 rpm (Plain)
51 mph @ 3500 rpm
62 mph @ 4000 rpm
74 mph @ 4500 rpm
83 mph @ 5100 rpm
Note: Above numbers motor was about 4 hrs old, no chop fresh water like glass boat was stuck to the water, my higher speeds were after motor was broken in and there was a little chop maybe trimmed a liitle different ???.So my drive ratio must be 1:36,how do i figure out my ratio.
32 mph @ 2600 rpm (Plain)
51 mph @ 3500 rpm
62 mph @ 4000 rpm
74 mph @ 4500 rpm
83 mph @ 5100 rpm
Note: Above numbers motor was about 4 hrs old, no chop fresh water like glass boat was stuck to the water, my higher speeds were after motor was broken in and there was a little chop maybe trimmed a liitle different ???.So my drive ratio must be 1:36,how do i figure out my ratio.
#18
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rod you cant go buy that or your ratio are you runing the boat on a river or lake call throtle up and have them figure it out from what i understand normal slippage is about 12% do you have a boost gauge on the boat if your hp is over 700 you should be able to get the rpm out of the boat with that prop what exhaust do you have. i just sold the bravo i have a q4 25 and 27left
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i have a boost guage,fuel pressure guage,oil temp guage,innercooler water pressure guage all at the helm,they all read correctly CMI E-Tops & mufflers for exhaust ,i have a feeling my blower was a little tired @ the end of last season i'll see when i run it again this summer after be rebuilt.I suspect i will need a bravo 4 blabe 28 pitch labbed,just to get the extra r's im lookin for, i have tried to get a hold of b blades thru e-mail but no response they seem quit busy, i hear these guys put out a good product and no what there talking about.