Hmmmmm....Labbed but no RPM improvement
 

Doesnt make any sense but I just had a Hydromotive QIV 23P labbed by a local shop and my RPM's didnt change at all..(The blades are clearly thinner so I know they worked on the prop). Not sure if a stern lifting prop is best with this hull
Currently running at 4500 RPM...I have a 454 Mag EFI which Im told should be running 4600-5000 RPM.
Ive run a 21P Mirage (not plus) and am at 5100 RPM which is too high...
Should I be looking for a new prop? 23P Mirage Plus (which is more of a bow lifting prop)??

I highly doubt a Hydro Q IV is the right prop your boat. "Local Shop" probably does not have the knowledge to lab a prop to the exact needs of your boat.
5100rpms is not a problem on a 454mag as long as you are not banging the rev limiter all the time. You could easily have some more cupping added to the prop to reduce the rpm a little. A stock 21 Mirage Plus will also drop the rpms about 200 with no speed loss.
The best prop would probably be a labbed 23 Mirage Plus......labbed by BBlades, not the local shop.

Why?

Because Q IV's create stern lift and not bow lift. They are better for boats that are designed to run flat, like stepped hulls and cats.
Conventional V bottoms generally run best with Mirage Plus' or Bravo 1 props.

Ive got a PM out to BBlades but no response yet. What is the charge to lab a prop? I just ordered a 23P Mirage Plus off ebay.

I'm pretty sure BBlades is $90 a blade.

Test the 23 Mirage Plus and record rpm and GPS speeds at 500rpm increments. Also, note what you like and don't like about the handling at 500rpm increments. He needs a baseline before he can custom lab it for your boat.

If I had to guess based on your posts, I would say you will spin it around 4700rpms, which will make it perfect for a lab job.

Griff--I hope you are right. In all honesty if Im hitting 4700 RPM and am back around 60-62 MPH Ill be happy and may not even lab the prop.
Ill post some numbers once I get a chance to try the prop out.

Sorry for the delay. I responded to your PM

Brett

I took my boat out yesterday with the 23P Mirage Plus and what a difference! One word--WOW!! My RPM's increased from 4500 to 5100 and my speed went from 57 MPH all the way to 63 MPH. Its just screaming now! I do have some chine walk at WOT but otherwise I cant believe how much more power I have.
No doubt about it--the Hydromotive Quad IV is NOT the right prop for my boat--you were right! Thanks again for the input!

Im going to be selling the Hydro QIV 23P if anyoine wants it!!

How do you think the midrange and cruising speeds are compared to the 4 blade? I am running a 23p Rev 4, and have a 23p mirage plus on the boat for a backup. It is my impression that the midrange speeds were better, and that overall acceleration was better, especially with a heavy load in the boat.