what is a good prop slip number ??
 

ran mine and im around 12-13% slip depending what calculator i used.
whats a good or great prop slip? and if mine isnt good what can i do to get it better?
ive had 4-5 different props on my boat and the one on there now seems to be the best. its a 24p b1 that i had pitch down to a 23 and it seems to handle good, gives good mid range and same top end as the labbed 24, and a stock 22. i run it around 4800 rpm

thanks noyzee

That slip# is fine on straight bottom V.

I like this one http://www.rbbi.com/folders/prop/propcalc.htm

that one puts me at 15%

15% seems a little high, mine is at 9.8% What is the make, model, year of your boat? Do you have a stepped hull or strait v? Do you know how deep your drive is? Is your goal top speed or tubing and skiing?
I noticed you are running 4800 RPM. What engine do you have?

Slip does not make a lot of difference as long as the boat performs well and at the correct rpms.
More slip also puts less stress on the drive.

True, every boat is different.

Very true indeed. Found this from an old mail from Julie @ Throttle up, just for kicks. It's from when we dialed a friends 38 Lightning in a few years ago.

"If slip is at 16%. This is actually good or OK for a Fountain. Reggie Fountain delivers many of his boats to his clients with 16-18%. Fountain are the exception to the rule when it comes to slip. Sometimes when we get a boat at 16% - 17% slip and we bring the slip down to like 9-10% , we actually will loose speed. So, in the case of a Fountain I am not alarmed about 15-16%"

X2 - use slip as a tool only and don't get too hung up on it. A friend's Checkmate runs a Bravo and has much higher slip numbers when compared to a Hydro QIV. But the boat is faster and has better manners with the Bravo.

its a 2003 checkmate 26 ZT it has a very small step/notch in the hull. like 1" and its not a curved step its just a little one, it has a small notched in the transom about5-6" and about 14" wide and 4-5 inch tall.
not sure on the drive hight.
single 496 mag

the boat doesnt seem to care about the prop. i have had so many props and nothing changes besides the rpm pretty much.

boat came with a 22p b1 and it would run 60 mph but with the boat light it would hit the rev lim and cruz speed 3600 rpm was about 40 mph

i put a b blades prop on it, he did a 26 with lab and cup and it would only turn 4400 ish but cruz speed was like 46 top speed was 58

he then sent stock 24, that went 4500-4600 and ran 59-60 with cruz aaround 43-44

then labbed it and put cup and the boat ran about the same but seemed to be very light in the bow and flighty

then tried a 23 3 blade the boat hated it, it blew the prop out bad, i could not trim it at all

then tried a hydromotive 25 pt qd4 and the boat handled unreal but would only run 4600-4700 but 56-57 mph

i then took the b blades labbed 24 and had a local place take some cup out and pitch it to a 23 and it seems to be the best so far. it runs 4700-4900 depending how the boat is loaded (coolers, fuel, people etc) it cruz at 43-45, handles good and tops out between 59-61 depending on the day. beginning of the year with me and one other light guy and 1/4 tank, no coolers, grills, floaties etc etc it ran 4900 @ just about 63 between 61-63

the boat seems not to care what prop is on it. lol

Sounds like you are where you should be. Don't see why the 4600-4700 rpm's are a problem for you, it's not a HO. 4400-4800 is what the motor is build for, and 4700-4800 is usually the rpm's to shoot for when going for top end. The 26" Bblades prop looked like a really good cruise prop.
61mph is a good everyday number for a single 26' with a 496mag. Be happy with it, and run it like you stole it.

im ok with it over all. the bblades prop had way to much bow lift. it didnt help with speed and it made the boat very flighty in small water. with less bow lift it handles better and didnt loose any mph.
i was just checking into it and see what was what. be sure i was close.

On a straight hull V-bottom, we like to shoot for 10% slip and usually settle at 14-15% Anything over 18% is unacceptable as high prop slip creates gear chatter, hammering out the lube between the tooth face, hence shortening gear life.

Sounds like your boat is running pretty good.

Kurt :drink:

great, thanks for the info.

slip also depends a lot on the props on my boat with a 24p maximus i am at 8% slip at 53mph, same boat with a 26p Bravo is 16.5% slip at 53mph. The difference is that the maximus abuse the drives and engines and the bravo is easy on them, obviously the boat has different performance with the two props but i think the bravo is a better choice for reliability.

the biggest problem with slip calculators is the "pitch" on the prop may not be the actual pitch unless you have your props propscanned there is no way to know.