Crazy Stilletto prop question

[walleyehed]

Re: Crazy Stilletto prop question

I think you need to be as far out as you can and still have a place to mount the top cylinder bracket.
I've punched in all the data you have given here and what we had talked about, and the recommendations I'm getting are from 18-21P both 3 and 4 bld.
I have also factored in your altitude, although low, I want the closest guess we can make.
I'm going to discuss this with Steve at Precision and see what he thinks....

 

[Tail_Gunner]

Re: Crazy Stilletto prop question

:}

................... Thats' using the 22p prop never got a chance to take a pic with the 20 to much first time excitement

 

[Tail_Gunner]

Re: Crazy Stilletto prop question

I took some time to use a prop slip calculator and a prop selector, am i inputting this right that is the prop is a 20p 4 blade so i enter 20 or should i enter a 21p for the extra blade? The reason i am asking the number's seem a little out of wack aka 4% slip? The rev limiter is setup for 5000 and the 20 doesnt hit it (4900) Or can gps be a few mph off?

 

[walleyehed]

Re: Crazy Stilletto prop question

I get 7.5% slip...
I believe the GPS is right...the tach "might" be off just a hair..25-50RPM.

 

[Tail_Gunner]

Re: Crazy Stilletto prop question

Always something new to understand, using

http://www.go-fast.com/Prop_Slip_Calculator.htm

with 1.66 gears @ 22p @ 4400 = 55 actual is 53.4 = 4%

1.66g @ 20 @ 4900 =TS 56 actual is 54= 3%

1.66 @ 19 @ 5000 = TS 54 actual is 49 =9%

It's a generic all around tool im sure, as well as useful. however i'am but im gonna ask. what other variable's are you factoring in........ or are you adjusting the tach a tad? 8) had me feeling good there about those props 6% gain........ lol i errr this boat can do no wrong......

 

[walleyehed]

Re: Crazy Stilletto prop question

8-9% is very possible and very good...3-4% shows the tach is likely off a hair...or you're running a Dhadley hull with a TXP....
The trick is to know what numbers to plug in for pitch.
The 20 and 22 are same design Bay Pro II's.. plug them in at 21 and 23 and see what ya get..... If they were std, run-o-the-mill props with no cup or other features, we'd use "20" and "22"....but they isn't std., mil-spec props...d

 

[Tail_Gunner]

Re: Crazy Stilletto prop question

Ok tabs on and the chine walk is gone, i sure wish i would have taken 0-50 time speed measurements they sure smooth out the launch, they may look a little close to the keel but that is 15" from the center.

 

[Tail_Gunner]

Re: Crazy Stilletto prop question

Just finished trying a Stilletto 21p 3 blade, it is not as smooth as the 4 blade Stilletto's nor does it lift the boat as high. It also setup's some kind of harmonic buzz in the hull just as the 19p factory volvo

But it does a couple of thing's that require less adjustment, when reaching the sweet spot (fully trimmed, maxium rpm & speed ) it takes on coming chop a bit better than the Baypro's 4bl those prop's you have to trim them back in for the bow to cut the chop a bit better. It is also faster 55.3 mph @ 5000 rpm and requires less trimming to reach that speed.

The trim tab's have eliminated the chine walk, today i was running in 6 inch chop and @ wot you could feel the boat getting light yet no pronounced left to right bouncing. the 4 blade's did have a more tourqey feel and smoother all over feel, but the 3blade while less tamed was faster.


1 person 215lbs & 200lbs weight & 37 gallons of gas

19 p 3bl AL 49mph @ 5000 Factory Volvo prop alum and hitting the rev limiter

22 p 4bl SS 53.5 mph @ 4400 rpm Stilletto Bay Pro

20 p 4bl SS 54 mph @ 5000 rpm Stilletto Bay Pro

21 p 3bl SS 55.3mph @ 5000rpm Stilletto ADVANTAGE II

_____________________________________________

1.66 gears @ 22p @ 4400 = 55 actual is 53.4 = 4%

1.66g @ 20 @ 4900 =TS 56 actual is 54= 3%

1.66 @ 21 @ 5000 = TS 60 actual is 55.3 =8%

1.66 @ 19 @ 5000 = TS 54 actual is 49 =9%

Precison may i request a 4 bl 21P ohh yes and x7 alloy ........

 

[Ron G]

Re: Crazy Stilletto prop question

very good numbers and data.

 

[Tail_Gunner]

Re: Crazy Stilletto prop question

.

 

[walleyehed]

Re: Crazy Stilletto prop question

T.G., are both of the Stiletto 4-blades the "exact" same blade shape?

 

[Tail_Gunner]

Re: Crazy Stilletto prop question

I think so.........actually never looked. I'll look and post a pic of them, my eye's just might not know what there looking for.

 

[walleyehed]

Re: Crazy Stilletto prop question

I think we got somethin' funny going on with those 4-blades, because 2" in pitch lost 600RPM on the 22P and 1/2mph slower.......something is wrong right there.....don't know why it took me this long to catch it but I think you have 2 different bld designs...

 

[Tail_Gunner]

Re: Crazy Stilletto prop question

All Three props 22 20 21 it wont change

4bl 20p 2 3/8 height

4bl 22p 2 1/2 height

3bl 21p 2 3/4 height

 

[Tail_Gunner]

Re: Crazy Stilletto prop question

The only difference i can find is the 20p 4 blade is 1/8 higher than the 22p 4bl..............:}

 

[walleyehed]

Re: Crazy Stilletto prop question

In this last picture with the black reference lines, the prop on the left has more pitch. If it says other-wise, something is astray.....
Can you list the 2 P/N's of the 2 four-blade props?
We'll get this figured out...

 

[Tail_Gunner]

Re: Crazy Stilletto prop question

:}......I stand corrected and you were right, the prop on the left is a 22p and the other is a 20, you have saved me some shipping costs ........thank you again walleyehed. If your ever in oregon i'll buy the worm's we have a huge population of Walleye's and hardly no one fishes them, 8) there not to bright either here's a pic of them stacked up below one of the dam's thinking there Salmon....

The prop product numbers are 45420 & 45422

 

[walleyehed]

Re: Crazy Stilletto prop question

that's the right p/n's....i just don't know why we got a 600rpm drop in 2"...it's like the 22 has so much stern lift it's pulling harder and forcing the bow down...
i'm wondering if a pro bass 4 in a 22 might give some better numbers and have the smoothness of the other 4-blds?

 

[Tail_Gunner]

Re: Crazy Stilletto prop question

Well i did give it every chance to get up to speed both props same day with in minute's of each other, wind water load's no variance, trying to find the sweet spot i just keep triiming it out watching the tack & speed and waiting for the growl to start or the tach jumping indicating slip......... but this is going to a speed prop one used having fun. The 4 blade i have now is pretty sweet and will be used most of the time

 

[walleyehed]

Re: Crazy Stilletto prop question

Keep me posted on your trials......
I also want to note I've been told the smaller diameter pro bass-4 performs quite well on sterndrives for reason's unknown...maybe because of a fixed drive heigth...