2018 R7 380VP 50MPH Red line??

[TcR7]

I am curious if anybody has changed prop to save some rpm's. I don't need to go any faster on top end, but would like to run a few less rpm's at cruising speeds between 30 and 40 mph. Loaded with 4 adults, top up, it would run right at 6000 rpm at 47mph, top folded up and by myself, 6100 rpm right at 50mph. I was running with trim assist on, and no tabs in the home position. It has plenty of low end and snap at cruising speeds!. It is way more responsive than my old 272 with 420hp 496.

I was wanting to see the fuel economy on the screen, I have it displayed, but no info is reading out. Any thoughts?

[cmattj]

Hey TcR7.

It would make perfect sense on paper, and of course some lower rpms would be seen in lower rpm ranges with moderate speed and throttle.

But adding pitch creates a strain as well. For example your current ability to find Max rpm means the prop frees up throughout the range.

Adding pitch which is (“inches per 1 revolution) adds thrust propulsion,and the power needed to maintain thrust is where it strains everything.

Get your out drive ratios and prop numbers. Get your current elevation where you boat, as we have other members with your similar set ups and can compare.

Cobalt has set your boat up with anticipated weights and conditions it will most likely see.

Can it be improved? Probably. Can it change the longevity of the drivetrain? Definitely.

Baby steps as you may be where you should be.

[Tuscany]

Same issue here. F6 prop would be the answer.

[Norris_Boating]

For the fuel economy info, Volvo has an extra add on that isn't included in the Cobalt, I can't remember the name right now, but read it in the Cobalt manuals that came with the boat. I will try to find it and post it.
50 is pretty good, I maxed out at 48 today, same configuration.

[Norris_Boating]

Ok just found it, it is called "TRIP COMPUTER"
https://www.volvopenta.com/marineleisur ... puter.html
AVAILABLE DATA
The system is extremely flexible and functions depend on what sensors are chosen. The data available is instant fuel rate, trip time, trip fuel, average fuel rate, and time to empty. With extra sensor or NMEA interface, instant fuel economy, trip distance, average fuel economy, and distance to empty is also available.

[TcR7]

Thanks for the info, it's at dealer now getting 20 HR service and a few warranty items taken care of. I will get their input before swapping prop sets, but going to F6 prop set is very tempting!
I suppose the trip computer is an unlock that they might want a small fee to do??? Too bad that it is end of season for me, I will patiently wait till spring to decide on prop set.

[Big Block Power]

Where do you boat at. I have a spare set. Lol

[Gail Force]

Solution. I have a 2019 R7 with the Volvo 380 and the same issue. 6100 rpm with f5 props as delivered by cobalt. Published recommended rpm is 5600 to 6000. I spoke to my dealer Boats by George, with out a hesitation bring it in and we’ll try the f6s. Boom 5950 maxed out and picked up 2 mph. So I drove down to him 4000 rpm and 30mph. Drove home 30mph and 3700rpm.
Thank you George!

[Big Block Power]

I wish we could see the prop charts fir the r series and engines.
Looking on the Volvo website 6000 is the rpm they want. Your only 50 under that right now. Nothing wrong with that. What is your boating style? Just cruising? How did it change your hole shot. That's what I would worry about more than anything else. What will the rpms do once it gets hot out and full load. That's what you will want to watch. I hope this solved your concern though. Keep us up to date please. Thanks.

[BobRae99]

I wish we could see the prop charts fir the r series and engines.
Looking on the Volvo website 6000 is the rpm they want. Your only 50 under that right now. Nothing wrong with that. What is your boating style? Just cruising? How did it change your hole shot. That's what I would worry about more than anything else. What will the rpms do once it gets hot out and full load. That's what you will want to watch. I hope this solved your concern though. Keep us up to date please. Thanks.

The dealer has them. I looked at the one for the R3 before I selected an engine.

[Big Block Power]

I wish we could see the prop charts fir the r series and engines.
Looking on the Volvo website 6000 is the rpm they want. Your only 50 under that right now. Nothing wrong with that. What is your boating style? Just cruising? How did it change your hole shot. That's what I would worry about more than anything else. What will the rpms do once it gets hot out and full load. That's what you will want to watch. I hope this solved your concern though. Keep us up to date please. Thanks.

The dealer has them. I looked at the one for the R3 before I selected an engine.

Correct the dealer has them we don't. They just don't publish much sometimes. Darn them!! Hint torque ratings 430!!!

[BobRae99]

I wish we could see the prop charts fir the r series and engines.
Looking on the Volvo website 6000 is the rpm they want. Your only 50 under that right now. Nothing wrong with that. What is your boating style? Just cruising? How did it change your hole shot. That's what I would worry about more than anything else. What will the rpms do once it gets hot out and full load. That's what you will want to watch. I hope this solved your concern though. Keep us up to date please. Thanks.

The dealer has them. I looked at the one for the R3 before I selected an engine.

Correct the dealer has them we don't. They just don't publish much sometimes. Darn them!! Hint torque ratings 430!!!

Which ones do you want? I’ll ask my dealer. I’m not calling him twice a week anymore to discuss options, because I’m all set so I think he is a bit lonely.

[Big Block Power]

The dealer has them. I looked at the one for the R3 before I selected an engine.

Correct the dealer has them we don't. They just don't publish much sometimes. Darn them!! Hint torque ratings 430!!!

Which ones do you want? I’ll ask my dealer. I’m not calling him twice a week anymore to discuss options, because I’m all set so I think he is a bit lonely.

It's not a big deal to me so don't bother him. Thanks though. I was just curious what they are putting on the 380 and 430 and exactly what rpm they are hitting. They may even run diff gear ratios.

[Gail Force]

SO I guess everyones boating life experiences and information gathering processes are different. I was always taught that a motor had a recommended operating range. The goal in selecting a propellor was to find one that allowed you to be in the upper portion of that range and not go over. So my new R7 with a full tank of fuel, 6 250 lb guys, auto trim on, running down the lake for lunch was over tacking at 6100 rpms. I typically don't carry more than that. Typically its just me and the wife. Volvo's recommended published "range" is 5600 to 6000, any place in that range is supposed to be safe, my experience tells me to be in upper part and not to exceed. Thus the prop change from F5 to F6. The change stopped the over reving of motor. Want to really make your self crazy go too Cobaltboats.com, owner resources, select owners manual for a year and series and it tells you the lower units gear ratio, engine model hp and prop set. Now ga back thru a models production history and see the gear set changes and prop changers. Im not a expert just trying to do what I feel is right for me to protect my investment. So when the 45 year old son come up to lake they don't blow up gramps new boat. Ha

[Big Block Power]

SO I guess everyones boating life experiences and information gathering processes are different. I was always taught that a motor had a recommended operating range. The goal in selecting a propellor was to find one that allowed you to be in the upper portion of that range and not go over. So my new R7 with a full tank of fuel, 6 250 lb guys, auto trim on, running down the lake for lunch was over tacking at 6100 rpms. I typically don't carry more than that. Typically its just me and the wife. Volvo's recommended published "range" is 5600 to 6000, any place in that range is supposed to be safe, my experience tells me to be in upper part and not to exceed. Thus the prop change from F5 to F6. The change stopped the over reving of motor. Want to really make your self crazy go too Cobaltboats.com, owner resources, select owners manual for a year and series and it tells you the lower units gear ratio, engine model hp and prop set. Now ga back thru a models production history and see the gear set changes and prop changers. Im not a expert just trying to do what I feel is right for me to protect my investment. So when the 45 year old son come up to lake they don't blow up gramps new boat. Ha

He wouldn't do that would he. Lol he's all grown up
I think you and Tuscany might be in the same boat on over reving. Yea If it's just you and the wife and close to that 6k mark your golden. And glad It worked out. Can't wait to see pictures of her on the water.