Hello guys i have a 28' bowrider with twin 260 hp 5.7 with bravo 1 drives and 19 p vengance props i was thinking about getting a set of 21 p rigth now im turning 4800 rpm wot, the boat weigth arround 6500 poubds. It runs in the high 50's once im over the 4000 rpm i hit the gas an it revs up at 4800 very fast but does not go much faster i can cuise at 3100 rpm t 32 mph or so there is local guy tha has a set of 25 p mirage 14 3/4 for 300$ for both i figure i try them but if i.s going to be a waiste i woul nit try , any help will be apreciate it, thanks for time in advance, eddie

Going from a 19 to a 25 is huge. There is no way you will be able spin them. 6 inches in pitch equals at least 1200 rpms difference at WOT. 21's might even be too big.

Thanks very muhc i though So, But is better to ask a stupid questions as suposed to fix a stupid mistake. I will keep looking for a set of 21, now i been told that every inch is suposed ( technicly) give or take 100 RPMs, so if go to a 21 the engine should still rev up to 4600 rpm? is that rigth, also maybe someone knows the answer to this, how come from 4100 or so to 4800 the boat does not really go muhc faster, is the prop not grabbing any more? Thaks in advance again !

Every inch of pitch change is about 200rpms when using the exact same make/model of prop.

bump ....

Can i upgrade my intake manifolds and carb to a 4 bbl carb and get the xtra 40 hp or soan then can i turn a 25 p prop? My motors have 2 bbl carb they are vortec head i seen many smakm block 350 claiming 300 hp or more , so i figurea it has to be intake, carb amd roller cams ' so maybe i just put the edelbrock1409 4bbl and the performer intake manifolds i should turn a higher pitch prop or is it not really worth it ? Thank in advance!

A 40 hp increase per side still won't be enough to spin to 25's. 40hp will gain 200- 300 rpms at WOT with the same props.

You need to try some 19 or maybe 21 Mirage Plus props to get a good baseline.

Ok, i think i will get a set of 21, since i have a set of vengance 19, can i get then labeled and will that make a diference? Also what do the actually do, im sorry for my ignorance!

revolution 4 blades would be the ticket for your ride..

Griff can I have pitch taken out of a set Mirage props??