Griff

Exactly what engine do you have???? The 502mag should not be in a 2011 boat.
The 8.2 mag is the newer one and comes with 380hp or 430hp in the HO version.

Either way, an 85hp gain is a stretch. I would bet you might gain 200-300rpms.
Whipple claims 7-8% on the 496 HO's and thats about 30-40hp.

A true 85hp increase is probably 400-500rpms.

BrianH244

[IMG][/IMG]

BrianH244

Sorry its 380hp. Its the new 8.2 mag

BrianH244

http://speedonthewater.com/new-boats...ry-8-2-engines

cig92

It looks like you have done your homework. You should see 3-400 rpm and I would keep your prop and have it labbed. That alone will get you a few rpm and mph. It will be the cheapest speed you will ever see at 4-500 bucks

BrianH244

Yes, I have done my research. My numbers for my prop testing (mph/rpm) are spot on. My smart craft has digital readings. Not sure why my boat hated a 3 blade. I was thinking a 25 pitch rev 4 since I got 4% slip with the 23 pitch rev 4. I'm not buying anything until I test the boat after the tune.
I will see what the 26 pitch bravo gets me then go from there. I will also be removing my cats, thank god I love a loud mota.

BrianH244

I will share this for those who don't know. The 8.2 mag 380HP and the 8.2 mag HO 430HP have the same exact internals. The ONLY two things that are different is the tune and also an air flow restriction which I will post a picture comparing the two. I will obv need to change mine out since I have the 8.2mag. On the right, mag air flow and on the left HO airflow. [IMG][/IMG]

low_psi

The reason your boat reacted poorly with a 3 blade is a high X dimension. The higher you go the more blade you will need to bite. My previous Velocity 260 with a standard X (Which is pretty high on the Velocity) wouldn't even get on plane with a 3 blade prop. It would blow out at 3000 RPM..... I would say go for the Stage II Flash. I had Whipple do the Stage II on my 496 Mag (non-ho) and even though the increase isn't nearly as much as they state for the new 8.2, I noticed a HUGE increase in low to mid range torque. I would say run a 26p Bravo and have BBlades tweak it. I ran a labbed 26p Bravo on my Velocity 260 (24' hull) on the Stage II 496 Mag non- HO) to a top speed of 72 in the Detroit River (wind at my back heading up river). The numbers indicate that would put it at around 74MPH in ideal conditions and maybe a tick faster in salt water.... I also had a pretty heavy sub woofer enclosure in the cabin (under the v-berth) and some heavy batteries in the engine compartment.

BrianH244

About how much did your velocity weigh?

low_psi

I never really weighed it. NADA Guide says 4000lbs (dry).