As some of you know im having major prop slip issues with my newley procharged 280. The guys at BBLADES sent me a 30p B1 to test and i only saw 73mph at 5200. That puts me at 26% prop slip. Thay told me the ideal % is 12%. With that I should be running 87mph. Brad and Brett gave me 2 options. try a "bigger" drive spacer than i already have. "i already have a 1" Or thay want to send me a 29p Hydromotive P5 5 blade cleaver prop. So I guess were gonna test the P5 first and see what happens. The only bad thing about that is the Hydromotive prop is over $1100 with out labbing and the B1 was $550...OUCH!!! Ill keep ya posted on the results.

I personally would drop the drive down deeper and stick with a B1 prop. I think your drive would live longer once you get the slip numbers where you want them. Also, given the HP a little extra slip isn't necessarily a bad thing. 15% might be a happy medium.

Is the 280's transom notched? Anyone ever try a neutral or drop box on a 280?

The transom is notched.

i haven't fully tested my laser yet...im curious to compare my results to yours...

I put a 1" spacer on and got down to 20% on a labbed 26 from bblades. We are still working on getting the slip down without reducing the rpm. Were you on the limiter running the 30P? Brett told me it might be better to have slip than to reduce the RPM. After blowing through 35 gallons of fuel on Sunday trying to get my top speed dialed in I have decided to focus more on cruising speed than top speed. My problem is too much weight on the boat. I refuse to offload the cooler, beer, amps, subs, microwave,margarita machine, fridge, a/c, anchor, etc to achieve a top speed.

Ill know who to tie up to for a floating wet bar. .

Love your thinking!

I already have a 1"spacer so i may be able to lower the gimble via the noched transom to get a lower X dimension. And i was right on the edge of the rev limiter

Tested a different prop yesterday from BBlades. It was a hydromotive P5 X five blade 29p 15" diameter. My top speed stayed the same at 73mph and i droped 200 rpm to 5000. That calculates down to 20% slip. Im still way off from where i want to be. I need 7 mph to be happy with this procharger purchace.

Where is your propshaft centerline in relation to the hull (not at the notch)? How deep is the notch at the transom?