I’ve got a Scarab 22 with a stock 454...
Seems like no matter what prop I use I top out at 60mph.

21p Solas 4 blade
23p Bravo 3 blade
24p Hydromotive 4 blade
25p mirage 3 blade

So seeing as all 4 of them top out at 60... is something else limiting me? Something with the drive maybe? Everything seems to run great. But I feel like there should be a top end difference with the different props

I think you mean 23 bravo 4 blade. Going to need more details. What rpms with what props? Is the drive lower in good shape? Does the hull like to be trimmed and aired out for speed? Any external water pickups or anything else hanging below the bottom of the hull, depth finder, trim tabs? Any hook in the hull?

Agree with IGW, and also, what year 22, plus which specific stock 454? You could be anywhere from 310 hp to 385 depending on the model. No matter what, it is unlikely on that boat that any 4 blade will be your fastest prop. The 25P Mirage, was specifically a Mirage, or Mirage Plus? Your 60 mph is on GPS or factory Speedo?

it might have not been a bravo then. It was a 3 blade for sure.

its a 1998 Scarab 22
drive is in good shape other than there is a skeg guard because the bottom of the skeg was broken at some point before I owned it
nothing on the back of the boat for any drag nor bottom water pickups.
boat is trimmed properly as well.
all speeds are on GPS
all props do between 4300-4600(redline)
and the 25p I believe is just a mirage not +

Skeg gaurd is possible reason

I kind of thought that too.. but would it not be causing drag to make the lower pitch slower? It just doesn’t feel right that a 21p and a 25p go the same speed. If the skeg guard was creating drag - I would thing the 21p would go slower still?

for some reason i fee like maybe something internally with the drive is too tight and just won’t let the shaft spin properly? I feel like I’m just at a loss... those 4 props should have noticeable performance differences and they don’t

Is there any difference with the props when you are at your cruising rpm with the speed?

Depending on what rpm for what prop (I’m assuming lower rpm
for the higher pitch props) sounds like you’re “hitting a wall” at 60, most likely from drag.

Yes, Horse Power...

All the numbers sound right to me. I ran 23-28 pitch props and all were the same top speed within 1 mph, RPM's changed. Cruise speeds changed at a given RPM's, but throttle position changed to achieve given RPM's. Also, pretty much every 22'-24' boat with a stock 310-330 BBC ran between 58-62 MPH. Which also correlate to the Prop-Slip Calculators.

a stock 330 isnt going to spin much over 46-4800 no matter what prop you put on it.