Dave M

Your numbers seem off. Either you are light on RPM or WAY high on slip.

You should prop for 5K rpms. A 28P @5000, with 14% slip still works out to 76pmh.

GO4BROKE

iTrader: (1)

Yup, stock 425hp

ROTAX454

Same numbers as above but at 79 mph, what does the prop slip percent show?

MahopacMarine

Kevin was originally running a 26 bravo 1 with those numbers. That should work out better. I think he confused it with a prop he is running now.

live wire

Must have been a senior moment .I'm spinning a 30 now or was last season and thought I only went up one size when we did the Whipple. But yes... I stand corrected stock was a 26.

bobl

Everyone needs to keep in mind that where you boat has a tremendous impact on speeds. You can only compare performances accurately when tested at the same location and time. As a comparison I had the opportunity to upgrade a 28 Nordic Heat and a 288 Sunsation to new 525 engines last summer. Testing afterwards at our local lake under very similar weather conditions on gps, same driver, netted the Nordic at 72 and the Sunsation at 73. Both had stock props. These boats ran low to mid 60's with 496 power. Take these same boats to where you guys are testing and they would pick up 5-6 mph, maybe more. So, please keep that in mind when reading all these results.

JustMercMe

I'm getting 76-77 mph(gps) no matter with a 27 mirage+ or a 28 bravo 1....Fully stock in fresh water on the Chattahoochee River.

MahopacMarine

Not to hijack, but how does the boat hook up and handle between the 2? Shoot me a PM if you would. I have a customer with a similar boat.

IRONMAN

I wonder how far into the triple digits a pair would push a new Shadow 30? Too bad we will never find out , Boat was far ahead of the available power and drive packages of its time.

JRalston

I saw 77 once early in the am by myself with less that 1/2 tank of fuel. usually 75.