what power is needed to get a 260 Velocity to 85MPH
 

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.

The 26 became the 280 as measured with a swim platform in 1999. Somewhere around the same time they came out with a 24 ft that was named a 260. Your Thououghbred 26 has the same hull as the Velocity 280.

Sounds like a great project....have fun!

Padraig

Padraig, thanks for clearing that up, i did not know that. Well the old owner had it painted and graphics done on the boat, he labeled it as a Velocity 260. i guess he just took the Summer Squall 26 foot spec and used that for his dimension.
HAHA oh well no big deal. My boat has an Aluminum swin platform bolted to the back of the Transom..

No problem. They are great boats. I had a 26 (280) before the VR 1. Look on the bright side....you now have a 28 ft boat. For docking, shrink wrap etc however I would call it a 26.

Padraig

I am running a 524 with a 1.5 Bravo 1 drive with a 28x15.25 Bravo 1 4 blade prop. I was running a 30p when I got close to 90. I will be trying a 32 once I get it all back together and the drive broke in. Talking to George at All American Drive, he is recommending I go to a 1.36 drive ratio and stay with the 28. I haven't decided which route I'm going yet.

So your 650 HP 524 " will spin a 30 with no problem with our hull? Hmmm. what rpm are u topping out at with that prop and what makes you want to go to the 32 pitch unit?
Is the mid range still there?
i was only running a 26 B1 but i couldnt really test it that well due to no hyd. steering and a very loose Gimbal swivel pin! Drive would float back and forth 4 to 5 inches while sitting still!!! That is one of many reason s i took it apart.

So your 650 HP 524 " will spin a 30 with no problem with our hull? Hmmm. what rpm are u topping out at with that prop and what makes you want to go to the 32 pitch unit?
Is the mid range still there?
i was only running a 26 B1 but i couldnt really test it that well due to no hyd. steering and a very loose Gimbal swivel pin! Drive would float back and forth 4 to 5 inches while sitting still!!! That is one of many reason s i took it apart.

I had a similar problem, cable helm with external hydraulic assist, so anything over 80 was getting dicey. I have since replaced it with a full hydraulic, which has helped greatly. I should mention that I have added a Hydro-Motive nose cone as well. I have a 27 Hydro-Motive 4 blade that I redlined at 6k, and the 28 Bravo is getting up there as well. I could still get on plane with 8 adults and 2 large coolers with the 30 and I had the rpms to the mid 5's with 4 adults and a full tank. The mid-range is awesome with the Bravo 1 Props, I run about 55 at 3500 and get almost 3mpg. The hull really doesn't like running slower than that anyway. First time out we were in 1 1/2' to 2' waves and I made the mistake of going slow, it beat us to death, I thought my wife was going to make sell the boat. Next day I went out by myself to get the feel of the boat and started trying more speed and it smoothed right out at 55, now I'm either idling or doing at least 55. Once I get the new drive broke in I will be able to do more testing to see what rpm's I am running at WOT. I'm not sure yet where it likes to run, it hits the rev limiter pretty hard with the Hydro-Motive prop.

Thanks for sharing this info... it will help me in setting upo my boat and not second guessing myself on my choices...

This is Living, please keep us updated once you get the boat back together, interested in the outcome

Bill

94 thoroughbred 26ft... not sure exact hp 600ish runs 88 on gps with a 30p B1 labbed by b blades

More money than your wife will let you spend. does she like diamonds?

LOL Been divorced for 10 years and not planning on getting taken a second time!!!

so i do what i want now....

my 02 280 would run right at 80 (hair over in perect conditions) was aprox 575 HP, from what I could tell (never dyno'd, bought the boat with the motor already built) It was a 509 with Jim V worked heads. 10:1 compression.

My now 98 280 has a 502 mag, and seems like a slouch compared to that boat. it runs about 67mph.

Bill,
Sounds like your engine should be producing 650hp but probably is not, your boat should scream with 650. Why not just rebuild and dial in current engine and drive setup. You probably wouldn't want to run too far into the 90's when driving turns into work.

I never got a chance to try a bigger prop once I got the drive broke in. I did wind it up with the Bravo 1 28P, I was crossing 5600 rpm and into the low to mid 80's. Based on how it was running the 28P will hit the 6000rpm rev limiter. I think I will need the 32P to get the rpm's down where they need to be.

NICE PROJECT, Not sure if this helps, but here's my info ?
I have a 509cid with custom grind cam, aluminum heads, CMI headers, intercooled Vortex super @ 7 lbs, All Max Machine Worx internals in a Bravo drive with 1:36 gears, FS Bravo 31P @5400-5600, runs 92-93mph anytime and has run 95&96mph a few times.Pump gas 91 Octane, Boat has 2 GPS speedo's (maximum the Bravo can go without nearly blowing out about 20% +slip) no nose cone. Mercury says 90mph on a Bravo. Some cats run 100+ with twin Bravo's. My 2 cents worth.
Dyno'd @ 798HP/808TQ
I would say a stock Bravo won't last long with 650-700hp, but what do I know ,I ran a stock Bravo on 550hp for 3 summers and I think the new owner is still running it, 24'V ran 83mph anytime, but was 1,500lbs lighter than my Velocity280, which I'm sure helped save the drive.

Good Luck and enjoy !

Can you send (or post) pictures of the fiberglass work you did to handle the extra power?

Update to my previous post. Had the motor rebuilt to aprox 625 hp. It definitly has more power. Only used it once before cold weather hit so i was taking it kind of easy but i should be back in the 80 mph club after a couple tweaks. I need a bigger carb before i get to carried away.

I ran a 26" 1998 260S/C with a Pro Charged 454 720 HP and 727 TQ 685 TQ at 2800 RPM. I ran a B-Max with a 1.30 and a 30 Prop I ran 94.8 on GPS never broke 95 might have with a shorty or labbing. Was turn key and ran that way for 6 years before letting it go during a divorce!

How is the chine walking? When I hit 85 the boat gets real light and likes to chine walk pretty good. I hit something late last season and had to have the drive rebuilt again. I had BBlades lab the prop and add some pitch to the B1 28P along with some cup for better bite. I just finished breaking in the drive and will be changing to NEO oil for some serious testing.

Mine chine walked stock at about 70, with big power it would drive straight through it with no problems.

Well, I hit something and twisted the vertical and prop shafts which of course cracked the gears. Didn't realize the extent of the damage when it happened, checked the prop immediately and no signs of impact at all. It was just a slight thud doing about 45, anyway the drive totally disintegrated the following weekend. So last year was pretty well shot. Had to spend most of this season breaking in the drive again. When I took the prop off I did discover one blade was off about .100" so I sent it to BBlades to fix and had them make some changes while they had it. They did a mild lab with an increase in pitch and added some cup. I think I wrecked a good prop, on flat water it porpoises like crazy and chines walks something terrible at 65. I learned that the slightest change in a prop can have drastic results on handling. I have a Hydromotive 4 blade that was a 26P and had it factory modified to a 27P that would run great at 80. The B1 4 blade 30P ran great to 90, wished I would have kept that one. Back to the drawing board on props, sending my labbed prop back to BBlades and hope they can fix it

I have NEVER broken in a drive. Heck I don't even break in an engine - much -
The only time a broke a
Bravo drive it was a defect in the vertical shaft. It broke clean right above the lower bearing. There weren't even any metal shavings.

It was a complete rebuild from All American Drive and they give a 24 month warranty if you follow their procedure, even with my horsepower.

Once I did bigger power I never had a chine walk problem anymore simple accelerated out of it if there was any and it stood right up. I only had any chine walk when in the 70's was WOT, once I had the power it went away when I would sit it up on the pad.

What does a 35 look like? Never heard of that one.

There was one at the Battleship Run this year. Reminded me very much of a 390. Hopefully Revelocity will post as I know he is more familiar with the 35.

padraig

Actually there are two variants. The Thoroughbred 35 was a shortened Thoroughbred 41 hull and deck (i.e. deep free board) whereas the one we saw at the Battleship Run (the first Ilmor V-10 powered Velocity!) was marketed as a Velocity 360 (36') based on a shortened Velocity 390 as you correctly pointed out. I believe that there were less than 5 built of either the 35 or 36.