I have a 25' with a 270hp 350cu Emi thunders
Corsa Quick and Quiet II and a 1.5 ratio drive 21 pitch Laser II turning 4600 rpm I attain 50.5 gps with one adult male 210lbs 3 females 115lbs each average and 3/4 tank fuel about 60 gals 3 gals water boat weight of 3900 dry 8' 3" beam, stepped hull
deadrise 18 degrees and transom angle of 12 degrees

cruise is 3800 rpm 40mph
3950 rpm 42.5mph
corsa has about a .7 mph gain in the open position

? prop recommendations the slip is higher than I like
close to 17% and I have to trim down quite a bit to keep the speed up

Where is the question?
You could always trow the 3 chicks overboard that would gain some mph but then your wallet would get heavier!!!

I think he is bragging about the 3- 115lb chicks. he is not thinking props

call if we can help just playing around.

? prop recommendations the slip is higher than I like
close to 21%

Guys, Was it to late for you last evening? Leave that board and get some sleep after 10 PM... You are running after a divorce ;-)

TOP DJ : I think I know what your question is...

Darin, correct me if am wrong, you are the prop expert.

Is'nt a laser II a pretty small diameter prop for a 25' 3900 pounds boat?
That would explain is 21% slip... Maybe he should go with a mirage. 2-3 mph gain?

If the laser prop has vent holes you need to plug them. The next option would be a mirage but you may need a little less pitch. a mirage plus will knock off a few more rpms so a 19 in the plus would be about right to keep the same rpm's good luck

ttt

I've been working the slip issue myself. Look at extra weight in the boat. Look at trim and the way the boat rides at WOT (bow high or stern high). Look at the condition of the hull bottom (dirty, wax, hook in hull. Look at the x dimension.

What does the boat run lightly loaded (rpm and mph)? With your numbers and a 12% slip you should see 56.0mph.

BT

THANKS for the order ? And, we will get you fixed up Darin

well I got under it and the hull looks like it was just pulled from the mold, so I dont think thats the problem.
Im sending my prop to Houston Props in a couple weeks
Im gonna get some more good readings this weekend
with 1/2 tank and 2 adults

the max the boat could really go at that HP and weight would be
56, so Im close to the limits of the combination.

Have you come across any used 27p, labbed mirages for me yet Darin? Been shopping for some in the seven to eight hundered dollar range for the pair.

Dave