270 convincor props and setup

[PA-Checkmate]

Picked up last fall and not much seat time but need suggestions mainly for the porpoise/bounce under about 50mph. Props I have played with:

23P Mirage+ 64mph at over 5000
25P Mirage+ 66mph at 4700
26P Rev-4 65mph at 4600.

What I noticed is the REV-4 wouldn’t hold with any positive trim in that rpm would increase but no mph gain. This prop was repaired by former owner so I don’t know how that effects results. The Mirage+ ’s are stock. I open to suggestions between your BBlades prop and Bravo-2 24P since I read they are more closer to 23p. I’m told the boat should run closer to 70-72 which would be great but still looking for overall improvement. Attached is the photo of the Rev-4

Today now have the Hydromotive Q4-x 15.25 x 24 witch turns 4700 at 66mph and us more responsive than the rev-4 and I can trim much father out.


I have tabs but without indicators so still figuring them out. Anyway to get hull to ride better under about 50mph without the moderate bounce.

Boat specs
2002 Checkmate 259/270 w/ 496 MAG-HO(425hp)
3 on board and 30-40 gal fuel when running all 3 props

 

[Chellems]

I am no expert bi have purchased and played with multiple props

I would ask you what you want from the boat. I would bet a 24P Bravo 1 would be your best all around option. They lift the stern very well and help reduce the porpoise condition. This will not be the fastest prop.
In my testing I found a Mirage Prop would run 200 RPM’s higher then the Mirage Plus. This allowed me to go up in pitch and still hit my target RPMS. The Mirage is a great bow lifting prop but she may porpoise at lower speeds.
The Spinelli I run (Star 4 Blade) now I have been very happy with and he will custom make the prop for your setup. He is not cheap, $1,200. But the first prop he built me 32P lost speed so he made me another brand new prop a 34P that will be going on the boat when the engine is done.
He is also out of the Finger Lakes so not to far for you to prop test with them.

Good luck

 

[Gimme Fuel]

On my 1997 253 at various power levels:

I absolutely hated the handling of the Rev4 prop I tried although it was one of the fastest top speed, handling sucked. It would bow steer dangerously at speed if crossing waves/wakes even trimmed out.

I tried a Mirage+ once, could hardly get on plane without blow out, and once on plane it I looked at throttle prop would blow out and forward motion ceased.

Bravo I good all around but could never rid the porpoise unless cruising nearly 50 mph. Boat never felt like it truly flew on the pad. When I added bigger motor and the extra 1000 rpm, it lifted stern too hard and got a bit squirrely. Off it came.

I ran an old Mach Sterndriver 4-blade round-ear prop for a while. Was actually a really good all around prop. Not as good as the hydromotive, but better handling than the Bravo I.

My absolute favorite prop on that hull was the Hydromotive QIV:
-I had a labbed QIV with shortened diffuser tube and added blade cupping. This was the best recipe for boat handling an trim attitude although it was a bit too tall in pitch for me so I couldn't use it in the end. Boat was perfectly balanced on pad at 65 mph with almost zero chine walk. Really eliminated the porpoise until down to about 35 mph with zero tab.
-I tried a box-stock one and it handled like the labbed one although needed ALOT more trim, basically right up to the safe limit of a Bravo's trim range. this one ended up being correct pitch I needed, and if I had kept boat I would have had the same lab work done I mentioned to make it the perfect prop. Flew boat perfectly on the pad just like the other stock QIV.

 

[ezstriper]

I agree with above comments, thinking bravo 1 24p would be best all around prop...tested many on my 251, 253, hard to beat the bravo 1. Mirage+ a tad faster but not as good everywhere else