In the process of upgrading my old superchargered (B&M 250 charger at 8lbs) 509 to a 548. I was wondering what power i need to make the boat hit 85MPH. Not sure if i shoiuld run the same supercharger on the 548 or go N/A with this build. i am using the same 320CC C/I Pro Topline New Zealand cyl. heads as the 509 had on it. Crane roller with 226-236 @.050 .581/.610 cam.I was told by the man i bought the boat from(and had the motor built) that the old combo was 650HP appox. I am sure it went in the low to mid 70's as i would just walk a friends boat that maxes out at 62MPH. i never trusted the water spedo... i was running a B1 26 prop.

Any ideas would be appreciated.
Bill

With a legit 650 HP you should be in the mid-80's already with your hull. Sounds like the right plan rebuilding the motor.

thanks for the reply i was hearing crickets lol!! i heard these were fast hulls and that is why i went with a Velocity. I only had this boat out the first year i bought it back in 2006 yea I KNOW right SADD!!

well it had some issues and i am kind of OCD about things. Soft stringers and motor falling down, gimbal ring was loose as all get out!. i could never take it wide open because it was scary!! so i pulled the motor and did a re ring, bearings oil pump back in 07-08. During this time I re-did the helm with new wood extension down to the floor next to the cabin door as it was loose too..Re-wired the whole thing with weather proof connectors and solddred and shrink tube. Re did all the wood in the motor area. doubled up the strings and added wing's to help support the transom for the extra power. (Saw this tears ago on a DCB in a magazine) lol, i also installed chine extentions from firewall to transom. epoxyied it all together and then glassed over it.. i am installing an Off Shore front motor mount this time also..

I am hoping i beefed it up enough. I also moved the trim tabs outward to make room for the dual hydraulic steering rams from Imco.. I have a SS Gimbal ring and Helmet for this too.

i would insert some photo's, but not sure how to attach one from my desktop???

I have a 280 that has been close to 90 with 650hp. You better plan on replacing that drive soon, I should have when I rebuilt my motor. When your ready, send it to All American Drive Service, they have re-engineered all of the weak components. I have my drive there now getting rebuilt after bearing failure caused a shaft to break and left me stranded. Make sure you have full hydraulic steering as the 260 will want to dance at just over 80.

...and if you have an iPhone, just download a GPS Speed app - I think I paid $0.99 (I'm sure Android has them too). Never guess again - the one I have captures your top speed too.

I will check that app. When I get it back together.. I re built the entire Helm /Dash with all new autometer gauges couple years back.. They have yet to be used.

I will check out that drive service, I will be very easy on mine as I was with the old set up to save it until I can get a XR or modded bravo..

THIS IS LIVING. Can you tell me what size motor and prop you ran with those numbers on ur 280?
Also. Does the 260 chine walk due to the pad width?
Mine is actually a 92 thoroughbred summer squall / Velocity, I am guessing Steve took this hull and renamed it the 260 in the newer models?

I think what you have is now called a 280.
I would think a honest 575 or so HP would get you to a GPS 85mph. I have got 80mph gps with my 260 with a 500efi spinning a 27p 15.5" dia. Hydromotive prop. I would think with a 100 more HP and 2' more boat would net 85mph fairly easy. BTW I LOVE the way the big diameter hydromotive prop handles.

This is a 26 foot boat. I found this on the I Net about Steve's take over when he left Regal boats.

In 1989, Steve started Thoroughbred Powerboats, which consisted of 3 models: 26- foot Summer Squall, 35- foot Majestic Prince, and 41- foot Bold Ruler; it was Kim’s idea to name the boats after legendary thoroughbred horses. Four years later, Steve regained control of what he started years ago- Velocity.
By 1996, Thoroughbreds were phased out and Velocity was bigger and stronger than ever.

What RPM do you turn with that prop ? I was only running a B1 26

I'm with the others, at 650 hp should get you there

Thanks for all the replies and info on your personal experinces with this hull. i have another thread started that talking about what power plant to run. I would like to run 700 or so N/A motor. I think i am swinging towards a 572 build, but some guys are saying if u have a 250 charger why not use it or up size to an 8-71. I really dont need 850-900 HP, i dont want to buy a drive to support that power level for one and the other is reliability with a blower motor.