This is really part 2 to my previous thread "454 Mag Intake Manifold Questions". The last time I had the boat out before pulling the motor, it ran 63 on GPS, full tank, 2 people on flat water. If memory serves me right, I believe it was turning about 4800rpm. I bought the boat from a close friend who owned it since 1994. He never checked it on GPS but it would run 72 on the speedo and would turn 5200rpm. Obviously very optimistic. Prop is a 23" 3 blade Mirage. Should I stick with this prop? Should I run a 4 blade? The motor will go back in making 525hp. Anyone have any ideas how fast she'll run? I'm figuring hi 70's, maybe low 80's. Also, I'm looking for as much info as I can find about the hull. (25' Larson Senza Spectre) It has a single step. The name "Duo Delta Conic" is on the hull sides, so I'm assuming it's a Harry Schoell design. Thanks in advance for all your help!

what rpm's do you want to run wot? Do you want top end speed or cruise speed?

Used to own a 1990 Senza Spectre, 454 Magnum stock, except for exaust. 72mph @ 5200rpm most i have ever seen; usually around 65mph - 68mph. Awesome boat to own.

If you have any more questions let me know??


any pics??

Challenger Offshore Powerboats has the molds now.

Thanks for your reply. Shooting for 5800rpm. What are the implications of either option. How much top end will I give up for better cruising speed.

depending on the prop you would see a 2mph loss in top end on a 4 blade compared to a 3 blade. post this in the prop talk section they can help much better.

I only have nondigital pics. As soon as I shoot some digital pics, I'll post them. Love the boat too. Does Challenger still produce the hull?

Thanks, I'll post it.

Do you still own one?

Challenger no longer has the DDC-26 in production (thats the one they made from the Larson mold) only a few were built.
They do use the DDC step in the other boats they build also; Active Thunder has the DDC in their 33' and 37'.

Wish I still had the Senza. have a cruiser now.