supercharged 25 outlaw prop size ?
 

I am trying to get between 5400-5600 rpm any sugestions would be great her is my total package.

Boat: 1998 25-0' Outlaw.
Engine: 540 BBC,B&M 250 supercharger dynoed @ 727 hp & 686 ft lbs torque @ 5400rpm smallpulley
& 4 lbs of boost.
Cooling system:Teague sea strainer thru super chiller
dumped thru transom,Large Imco oil cooler.
Fuel system: Areomotive pump & reg. single 1060
dominator nickerson blower carb,remove stock
one way stock ball valve @ fuel tank steady 7
lbs @ W.O.T. Note: Blew my 1st engine up
with only a couple hrs on it because of the one
way ball valve fitting at the tank baja puts in at
factory restricted the amount of fuel to the
engine leaned it out and that was it,won't do
that again.
Drive: XR sportmaster 2"shortie with shower no
extension box.
Steering: Imco dual ram not hyd.to the helm.
Top speed: 86-88 mph 4lbs 1000 ft above se level fresh
water 2-0' chop, bravo 4 blade 28 pitch non
labbed 220 degrees oil temp @ 5100 rpm.

Sent supercharger to teague they rebuilt it 100% they had mentioned it was very loose and i should see between 6-8lbs of boost.

What is your drive ratio? With the speed you are getting @ 5100 you can't be running a 1.5, with a 28 pitch prop. If your drive is a 1.36, and you can spin that 28 up to 5600, you should hit 92 with a 12% slip. With the added boost from having your SC rebuilt, you might be able to pull the extra rpm. How much $$ did Bob charge you for the rebuilt on the 250? Good luck, and hang on.
Bawana

P.S. I don't know what heads or cam your running, but, you would have to spin that 250 very hard to get 8psi. with 540 ci.
Keep that water flowing to that innercooler.
Bawana

its supposed to be a 1:50 when i purchased it,bob charged me 800.00 & they polished it

that sounds like its a wild ride! lets see some pics!

30 pitch B1 would be a good start. See my reply in the baja forum.
hope it helps. post pics and vid on that bad boy!

i had a 25 outlaw 1999 with 509 merlin heads and a 420 mega blower dyno was 765hp i ran an xr with 2 inch shortie no box ran 92-95 with a bravo 28 out of the box 1.50 bravo rpm was i believe 5800-5900

baja
 

pic of baja

That is one sweet 25 i can't seem to get that kind of rpm out of mine on the dyno hit 6100 before running out of hp.Did you ever try any other props,how many pounds boost,where is the boat now does it still have this same set up.

sold the boat and put the original motor back in it i also ran a hydro for a while boat needed alot of set up after motor came of the dyno 7psi on dyno in boat only 3/4 psi so i changed the pulley to get about 6/7 psi and then i had to re adjust the carb jets a little to get it just right. i still have some of the props.

Well who ever said you can´t get Baja hulls to run fast? 90+ mph out of 750 hp in a 5000 pound boat is pretty damned respectable, I´d 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.

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.

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.

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

If motor hp peaked at 5400 and can only turn 5100 as set-up a 30 pitch is going to kill it dropping the rpm's down even further,Smitty
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.

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.

i think the stock speedo is farley accurate compared my speed to hand held gps seemed to be within 1 mph

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

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.

i run the boat in fresh water lakes.

you may have to change the pulley on the blower on the boat the cmi e tops flow very well also a 250 is a little small for a 540 my motor came of the dyno it had 7 lbs in the boat only 3-4 lbs i had to play with the pulley and then i had to readjust the carb your e topps might flow better then the dyno headers

Nice setup!!

Looks great!

I was getting 83gps with a 26b1 at 6000rpm in the ocean. 1.50 gear, art

thanks for all the info guy's i have decided to exchange the 18" dana tabs with 24" and try a 28" labbed bravo1 see where this takes me ill keep ya posted after i try it.