5.7 monsoon with supercharger?

[TenTwentyOne]

Who is running a wake/ski boat at WOt for 10 minutes?

While they don't technically run at WOT, a surf tow will certainly run the engine in the "heavy load" portion of tuning. They certainly run for extended periods of heavy engine load, compared to a car. An improper tune in a tow boat would have the tendency to more easily cause damage, due to long durations of heavy loading. A car engine could withstand 1600 degree EGTs for 20-30 second bursts. Take that same engine, and run it at 1600 degree EGTs for 5 minutes, and it probably won't be running anymore.

IMO Tuning for a tow boat should be based more on a "steady state, high power" type application (like heavy trucks, airplanes, trains, etc)

[shawndoggy]

Who is running a wake/ski boat at WOt for 10 minutes?

I understand that you are willfully ignorant of surfing, but I think quite a few of the heavily loaded surfers (especially surfgate guys) do. when people are switching props because their boats are maxed out it's not because they don't want to push past half throttle. It's because they are at full throttle and the boat won't go faster.

Edited August 8, 2015 by shawndoggy

[oldjeep]

I understand that you are willfully ignorant of surfing, but I think quite a few of the heavily loaded surfers (especially surfgate guys) do. when people are switching props because their boats are maxed out it's not because they don't want to push past half throttle. It's because they are at full throttle and the boat won't go faster.

WOT on a 5.7 is 5200 rpm. People are seriously surfing at that rpm? WOT does not mean Im bogging down the boat so bad that I cant get more than 3500 rpm out of it. Inability to get to WOT is a prop problem.

[RTS]

Yikes....In 2003 when I bought my boat, I saw a test in a boat magazine that showed WOT on a 350 Monsoon burned in excess of 30 gallons per hour. If surfing needs WOT, that seems like it would be a very expensive day on the lake, and a day that could not be spent very far from a fuel dock.

[shawndoggy]

WOT on a 5.7 is 5200 rpm. People are seriously surfing at that rpm? WOT does not mean Im bogging down the boat so bad that I cant get more than 3500 rpm out of it. Inability to get to WOT is a prop problem.

WOT is "wide open throttle"

Redline is 5300.

There is NO WAY that an axis rolling off of the assembly line next week with a 5.7 and the lowest prop malibu sells will hit 5300 with all ballast (including factory PNP) full and surfgate deployed, even at sea level. won't happen. in a million years, won't happen.

[shawndoggy]

Yikes....In 2003 when I bought my boat, I saw a test in a boat magazine that showed WOT on a 350 Monsoon burned in excess of 30 gallons per hour. If surfing needs WOT, that seems like it would be a very expensive day on the lake, and a day that could not be spent very far from a fuel dock.

only if you can pump enough air through the motor to use that much fuel. Real world on a heavily loaded 5.7 boat that is maxing at around 3500 is probably closer to 7-8 gph.

so I've "heard" anyway...

Edited August 8, 2015 by shawndoggy

[oldjeep]

We're talking about different things. WOT is an engine spec that exists regardless of your particular application.

For my 2012, the manual says wot range is 4600-5200

Edited August 8, 2015 by oldjeep

[TenTwentyOne]

We're talking about different things. WOT is an engine spec that exists regardless of your particular application.

For my 2012, the manual says wot range is 4600-5200

That is just the spec for proper size on the prop...... Meaning, when you are Wide Open Throttle, that is what the boat should be revving at max speed. It is not a different meaning for WOT.

[boardjnky4]

Bottom line is offshore racing guys are building highly modded motors and must be tuning them somehow. It's not rocket science.

[TenTwentyOne]

Bottom line is offshore racing guys are building highly modded motors and must be tuning them somehow. It's not rocket science.

Yes, they certainly do. In the shop that builds the engines. On a dyno....

[mattpoland]

Then they learn it only take one nut and a puller to remove the prop. Done in less than an hour.

It wouldn't be an online forum without people that don't understand the question stating why it is a dumb question. I've called 4 engine builders here in southern california and they won't touch the motor because of the Cat and electronic throttle linkage. They said they don't have access to the computer until someone come up with a kit. Maybe Indmar could make something. I talked to Teauge, Pfaff, Turnkey, and Danzio. The first 2 are the guys when it comes to high power boats, the second two are more offroad racing. As far as I can tell it is not possible without taking off the cats. The last think I want to do is take off the CAT because the engine exhaust would stink while surfing. Out of the 537,1235,1273,2315, and 2419 the 2315 is my favorite, but the 2419 will push around the most weight. I have had the boat loaded to he point where it takes full throttle to maintain 23mph with 3 clicks of the wedge, and full throttle to wakesurf 11mph. Typically you only stay there for a couple minutes because someone falls, but it would be nice to have more power to etiher get to wakeboard speed faster, or surf with even more weight.

[Fman]

It wouldn't be an online forum without people that don't understand the question stating why it is a dumb question. I've called 4 engine builders here in southern california and they won't touch the motor because of the Cat and electronic throttle linkage. They said they don't have access to the computer until someone come up with a kit. Maybe Indmar could make something. I talked to Teauge, Pfaff, Turnkey, and Danzio. The first 2 are the guys when it comes to high power boats, the second two are more offroad racing. As far as I can tell it is not possible without taking off the cats. The last think I want to do is take off the CAT because the engine exhaust would stink while surfing. Out of the 537,1235,1273,2315, and 2419 the 2315 is my favorite, but the 2419 will push around the most weight. I have had the boat loaded to he point where it takes full throttle to maintain 23mph with 3 clicks of the wedge, and full throttle to wakesurf 11mph. Typically you only stay there for a couple minutes because someone falls, but it would be nice to have more power to etiher get to wakeboard speed faster, or surf with even more weight.

How much weight are you running? And more importantly how much in the bow?

[mattpoland]

Hey Fman - so last weekend, Full throttle at 23mph towing a rider:

- MLS + 200# lead + 2 people in bow

- tanks full + 1200 total plug/play + 7 people in the back

- 100# lead even w/ driver.

(estimate 3000 lbs + factory ballast)

2315 prop, 1400 elevation, about 4000 rpm.

[Fman]

Matt, that is quite a bit of weight. The only option to help you that I can think of would be to run some more bow weight. The lsv and vlx love bow weight and usually only makes the wake better (for surfing and wakeboarding). You have quite a bit of transom/cabin weight plus you are fighting some elevation performance loss. That 350 is probably at its max but I would try to move a couple more people in the bow, not ideal for passenger comfort but it could help a little.

Or go 2419 for a bit more juice, but sounds like you have already went down that road.

Edited August 8, 2015 by Fman

[BlastRlxi]

It wouldn't be an online forum without people that don't understand the question stating why it is a dumb question. I've called 4 engine builders here in southern california and they won't touch the motor because of the Cat and electronic throttle linkage. They said they don't have access to the computer until someone come up with a kit. Maybe Indmar could make something. I talked to Teauge, Pfaff, Turnkey, and Danzio. The first 2 are the guys when it comes to high power boats, the second two are more offroad racing. As far as I can tell it is not possible without taking off the cats. The last think I want to do is take off the CAT because the engine exhaust would stink while surfing. Out of the 537,1235,1273,2315, and 2419 the 2315 is my favorite, but the 2419 will push around the most weight. I have had the boat loaded to he point where it takes full throttle to maintain 23mph with 3 clicks of the wedge, and full throttle to wakesurf 11mph. Typically you only stay there for a couple minutes because someone falls, but it would be nice to have more power to etiher get to wakeboard speed faster, or surf with even more weight.

Curious point about the exhaust while surfing. Anyone who's running the supercharged engine from Indmar complain about exhaust fumes? If not, it's probably not a big deal to take off the cats with a supercharger installation.

[mattpoland]

I think I'm not alone with the Cat issue - the new 575 has a cat.

The two best wakeboarders I tow don't like too much bow weight - for Malibu they say weight the back till the boat porpoises, and then the front till it stops. Repeat until you run out of hp.

For Wake surfing, the more hull in the water the better.(bow weight). The new VLX is an awesome hull - iit amazing how the wake stays clean with so much ballast. Maybe acme

should make a 15.5 x 11.25 .105 cup.

I really don't care about top speed which made for some funny conversations with teague and pfaff. No really- i am ok cruising at 24mph, but I want to plow 11,000 pounds at 4000rpm. Repeat until they stop talking about top speed.