determining the right pitch
 

hey guys I am looking for a little help in determining what pitch props I want to try maybe this summer to try to get alittle more top end. I am currently running 500 EFI motors with stock 28 pitch Bravo ones.I get upper 70s on gps all day at around 51-5200 rpms. The best I have seen was 82 in a good chop on gps but only seen that once. Would a set of 30s get me up over the 80s mark more? I also thought about labing my 28s but seems to be about the same price of a nice set of 30s on here. What u guys think.

With 30's your only going to rev 4800-4900 rpms. Where's your rev limiter set at? Labbing your 28's will add a couple hundred rpms if you have room under the limiter. Will also be harder to plane with the 30's and be more sluggish all around. I'm going through the same thing with 30's and 32's. 28 five blades may be an option for you as well.

I think I can go up with the rpm's becouse I havent touched the rev limiter sence I have owned the boat.

5 blades won't go faster, unless your slip is terrible, try labbing your 28's, should increase everything a little

Using your numbers, it is a no brainer to Lab the propellers you have. This is only if these numbers are spot on. Your slip % is 12 using 78 as a top speed. Your rev limiter is set at 5400 unless adjusted. So, if everything is as stated and still stock, Labbing your current props is the best route. The top speed advantage will be obtained with the current props done correctly. Correctly, not a maybe shop.
Trying "so called" 30 pitch props on here is a some times a slippery slope.
Let me know any questions I can help with.

Brett

can any one tell me what kinda hubs I have in my props I never seen these befor.
[IMG]http://i1149.photobucket.com/albums/...psaibruchh.jpg[/IMG][IMG]http://i1149.photobucket.com/albums/...ps4mw6kyxz.jpg[/IMG][IMG]http://i1149.photobucket.com/albums/...psq0mruopb.jpg[/IMG]

standard mercury hub kit for 1" shafts

Relly. .. I have never owned a prop with that slip out spline

yes really

We / Mercury Marine came out with these square bore hub assemblies in around 1998. This has been the standard in the industry since. The beauty is they can be used on various engine manufacturer engines besides Mercury and can be replaced by the consumer rather than only by a prop shop if the plastic insert is used and happens to break.

Brett