Top Speed of the 555 hp supercharged LSV's

[Chattwake]

JRZ1 - I had an opportunity a while back to talk to some of the guys who tested a prototype with the supercharged motor. I was told ~ 50mph. You are right, in that the 555hp motor is and was intended to be torq monster and/or to provide a cool bragging rights option for those who don't slam their boats with weight. I am interested to hear some comments about fuel consumption with a loaded boat. I heard some stories about some guys running a lsv up at Norris with the supercharged motor and how much gas they went through in one weekend taking sets.

Edited June 17, 2011 by Chattwake

[Danno]

JRZ1 - I had an opportunity a while back to talk to some of the guys who tested a prototype with the supercharged motor. I was told ~ 50mph. You are right, in that the 555hp motor is and was intended to be torq monster and/or to provide a cool bragging rights option for those who don't slam their boats with weight. I am interested to hear some comments about fuel consumption with a loaded boat. I heard some stories about some guys running a lsv up at Norris with the supercharged motor and how much gas they went through in one weekend taking sets.

[Danno]

We have 35 hours on our supercharged boat now. With the stock prop which is a 14.5X16 we get 51 MPH out of it at 5500 RPM. We put on an 14.5X17.75 and gained 1 MPH to 52 MPH. The RPM dropped to 5100 at full speed.

These speeds are on our factory GPS.

Any suggestions for a prop which will give us a bit more speed with lower RPM?

Fuel consumption is not bad when surfing but is a bit heavy when cruising at 35 MPH.

The supercharger sounds sweeter than sweet.

[AndyP]

We have 35 hours on our supercharged boat now. With the stock prop which is a 14.5X16 we get 51 MPH out of it at 5500 RPM. We put on an 14.5X17.75 and gained 1 MPH to 52 MPH. The RPM dropped to 5100 at full speed.

These speeds are on our factory GPS.

Any suggestions for a prop which will give us a bit more speed with lower RPM?

Fuel consumption is not bad when surfing but is a bit heavy when cruising at 35 MPH.

The supercharger sounds sweeter than sweet.

It does sound sweet. Fuel consumption? That’s why there is a 52 gallon tank.

[WakeSwagger]

We have 35 hours on our supercharged boat now. With the stock prop which is a 14.5X16 we get 51 MPH out of it at 5500 RPM. We put on an 14.5X17.75 and gained 1 MPH to 52 MPH. The RPM dropped to 5100 at full speed.

These speeds are on our factory GPS.

Any suggestions for a prop which will give us a bit more speed with lower RPM?

Fuel consumption is not bad when surfing but is a bit heavy when cruising at 35 MPH.

The supercharger sounds sweeter than sweet.

Not trying to call you out (I am beyond envious of your boat), but if you are really trying to push your boat past 50, why did you buy a Malibu?

[Brett B]

Not trying to call you out (I am beyond envious of your boat), but if you are really trying to push your boat past 50, why did you buy a Malibu?

Why not? Maybe he boats on a big lake and likes to save some time on the way to his spot. Maybe he likes wakeboarding AND going fast, and doesn't want to buy 2 boats. Isn't there a Corvette edition VTX on here that goes faster than that?

[jjackkrash]

It does sound sweet. Fuel consumption? That's why there is a 52 gallon tank.

So you can run it for 45 minutes at WOT? Earlier in the thread it was mentioned that the burn rate is 63 gal./hour at WOT. I wonder what the burn rate is at cruising speed.

[Danno]

We bought it because we wanted a surf boat with the ability to cruise at 40+ for when we go up the river to the big lake. I was hoping for a boat that went upper 50's so when we cruise at 40 it would be not to bad on fuel.

Considering the power that we have, the fuel consumption is not bad.

I will fill it up with fuel and see how many hours we get out of a tank next time out.

At WOT you would be able to see the gas gauge move. We have given it a few bursts of WOT and the sound of the supercharger is worth the price of the fuel that we are burning.

Lots of comments from the people at the beach re the supercharger noise.

We are going to try a few other props to see if we can get the rpm down at cruising speed.

[WakeSwagger]

Why not? Maybe he boats on a big lake and likes to save some time on the way to his spot. Maybe he likes wakeboarding AND going fast, and doesn't want to buy 2 boats. Isn't there a Corvette edition VTX on here that goes faster than that?

I think my jealousy got the best of me on that post, you're right.

[jjackkrash]

We bought it because we wanted a surf boat with the ability to cruise at 40+ for when we go up the river to the big lake. I was hoping for a boat that went upper 50's so when we cruise at 40 it would be not to bad on fuel.

Considering the power that we have, the fuel consumption is not bad.

I will fill it up with fuel and see how many hours we get out of a tank next time out.

At WOT you would be able to see the gas gauge move. We have given it a few bursts of WOT and the sound of the supercharger is worth the price of the fuel that we are burning.

Lots of comments from the people at the beach re the supercharger noise.

We are going to try a few other props to see if we can get the rpm down at cruising speed.

That sounds about right. My neighbor gets pretty good milage with his supercharged Mustang unless he's stupid with the throttle. When the Supercharger kicks in, it snaps your neck and the fuel disappears. I am very curious to see how your boat does fuel-wise at a comfortable cruising speed, I bet its pretty reasonable all things considered.

[Danno]

We now have 75 hours on our supercharged boat. Fuel economy is very good. We have the boat out front on our dock so we usually go out twice a day for about 3 hours of surfing.

We spend about $100 to $120 per day on fuel. This is with full factory ballast, 750 # in the rear locker and 6 or 7 people in the boat. Cruising up the lake we average 35 mph and it does not use a lot of fuel. Even with lots of ballast and 12 + passengers we only have to tickle the throttle to get out of the hole surfing.

[AndyP]

We now have 75 hours on our supercharged boat. Fuel economy is very good. We have the boat out front on our dock so we usually go out twice a day for about 3 hours of surfing.

We spend about $100 to $120 per day on fuel. This is with full factory ballast, 750 # in the rear locker and 6 or 7 people in the boat. Cruising up the lake we average 35 mph and it does not use a lot of fuel. Even with lots of ballast and 12 + passengers we only have to tickle the throttle to get out of the hole surfing.

Tickle the throttle, no kidding. There is so much torque in this motor it’s crazy. I "tickled” the throttle a little to much and my brother hurt a couple ribs after I doubled him over.

[Deephaven]

With the big power and the big prop, we hope to be able to do our day drip cruises at 40 MPH and have decent economy. The odd 50+ burst of speed is nice but we have found from past boats that lots of power and a huge prop used half the fuel as a mid powered boat with a hole shot prop.

Exactly the goal if you ask me. The real question that I'd like to see addressed is how much of a "speed prop" can you put on the boat and still have reasonable hole shot, good feel for pulling a surfer, and have more top end with that buying you a higher cruise speed. So for those of you with the motor that have repropped have you lost the bottom end you need?

Currently with my 23 LSV and the monsoon in order to get the holeshot I want and need my cruising speed for efficiency is down around 22mph which is too slow for lake crossings. Adding more power and then re-prop would obviously be one cure for this. Hell, if I just want a speed rush I'll hop in my bass boat and fly across the lake at >70mph and burn nearly nothing for gas in comparison.

[nyryan2001]

How many problems have you had with the 555? earlier this summer the forums where flooded with overheat and exhaust issues.... Yours has ran well?

[Steve B.]

A little jealous here too. 555 hp on the Sunsetter would be saweeeet !

Steve B.

[Danno]

How many problems have you had with the 555? earlier this summer the forums where flooded with overheat and exhaust issues.... Yours has ran well?

No problems. We are running 91 octane because that is all they have around here and it runs great. Stock ballast plus 800 pounds in the surf side corner and 11 passengers today. Front ballast full plus 2 people up front. Huge long wake.

[Danno]

No problems. We are running 91 octane because that is all they have around here and it runs great. Stock ballast plus 800 pounds in the surf side corner and 11 passengers today. Front ballast full plus 2 people up front. Huge long wake.

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Just came back from the gas stop. 5 Canadian gallons per hour mostly surfing with the supercharged motor. We are pretty happy with that. That would be about 6 American gallons per hour.

If we go for a long distance at idle speed, a warning buzzer comes on telling us the engine is running too hot. We can surf all day and the engine runs nice and cool.

Has anyone tried different props with their Supercharged boats?

We usually put along at 30 - 35 mph but it is sometimes fun to pull out and pass another brand od Surf boat at 52 mph.

[jrz1]

Also had mine overheat once after prolonged idle. Hasn't done it since. No other problems. Seems to be getting smoother with a few hours. Around 55 hrs on mine so far. Haven't measured fuel consumption but I get the sense it does ok at cruise speed.

[Danno]

Have you tried different props. I would love to get a bit more top end.

[SunriseH2OSkier]

So I had an opportunity to drive a 32' Fountain with a pair of LSAs out on Lake St. Clair north of Detroit yesterday afternoon. 80mph in 1.5 foot chop in an open air cockpit is quite a rush... The acceleration from 45mph is impressive to say the least. The grin on my face is likely to be there for a couple more weeks.

On a side note, I now understand why dogs like sticking their heads out the window of a moving car.