R5 - R6 Performance Numbers

[BobRae99]

Hi All,

Looking at the numbers, it looks like, despite the weight difference, the R6 has comparable top speed performance to the R5 it replaces, but it is slower getting up on plane (no surprise).

The best time to plane in the R6 is with the 380 (4.1 seconds). The R5 with 380 gets on plane in 2.9 - 3.5 seconds. Can someone explain the R5 prop chart showing two different performance numbers for the same engine, gearing, and props? Catalyzed vs non?

Anyway, Big Block, which engine do you pick for the R6 stern drive? Go 430 for $9,000 and .7 mph?

BR


R6

V8/350DP 52.7/5,710/6.2 (time to plane)
V8/380DP 54.8/6,100/4.1
V8/430DP 55.5/5,950/4.2

R5

V8/350DP 52/5,900/3.1 (time to plane)
V8/380DP 53-54/5,800-5,850/3.5-2.9
V8/430DP 56/5,930 3.8

[dustinm]

Ugh. This is the first time I have ever seen a larger higher HP engine just plain not worth buying, speaking of the 430, not blue motor.

[BobRae99]

Ugh. This is the first time I have ever seen a larger higher HP engine just plain not worth buying, speaking of the 430, not blue motor.

Cobalt was recommending the 380 to me for the sterndrive model. If the 380/430 torque/hp curve is similar to the 300/350, then you get the same torque and hp until the 3/4 way to redline and then the 380 flattens while the 430 adds HP and a bit of torque beyond that.

It's pretty clear to me that the R6 needs the torque of the 380 to get moving reasonably quickly. 6.2 seconds to plane just isn't attractive to me.

[tgrace98]

I'd be interested to see the drive gear ratio they used as well to get these numbers. My R7 has a similar weight to the R6 and planes faster than the 380 R6 but has less top speed. 51 compared to the 54.8 number they are showing. I've seen 54 on my GPS before but that was on a perfect weather day, low fuel and just me in the boat. normal summer conditions half a tank of gas or more I am lucky to see anything over 50.

[BobRae99]

I'd be interested to see the drive gear ratio they used as well to get these numbers. My R7 has a similar weight to the R6 and planes faster than the 380 R6 but has less top speed. 51 compared to the 54.8 number they are showing. I've seen 54 on my GPS before but that was on a perfect weather day, low fuel and just me in the boat. normal summer conditions half a tank of gas or more I am lucky to see anything over 50.

350/380/430 all use the same gearing (2.32) and the same props (FH6).

Maybe less top speed for your R7 because of 2' more in the water?

[Big Block Power]

Bob where is the merc prop chart? I think the 430 8.2HO is going to be the winner here with the extra torque to get that pig on plane!
.1 I'm going merc and the fat heavy beast!
Bob 430 all the way. Or just drop a pitch and get that baby to jump on plane when now seeing that we don't care about top end!

[BobRae99]

Bob where is the merc prop chart? I think the 430 8.2HO is going to be the winner here with the extra torque to get that pig on plane!
.1 I'm going merc and the fat heavy beast!
Bob 430 all the way. Or just drop a pitch and get that baby to jump on plane when now seeing that we don't care about top end!

There are no numbers published for Merc yet. On the Volvo side, what, in your opinion is the argument in favour of the 430?

[NautiGirl]

Bob where is the merc prop chart? I think the 430 8.2HO is going to be the winner here with the extra torque to get that pig on plane!
.1 I'm going merc and the fat heavy beast!
Bob 430 all the way. Or just drop a pitch and get that baby to jump on plane when now seeing that we don't care about top end!

There are no numbers published for Merc yet. On the Volvo side, what, in your opinion is the argument in favour of the 430?

BBP's argument for the 430? Simple. It's the largest engine option in your list.

[Big Block Power]

Bob where is the merc prop chart? I think the 430 8.2HO is going to be the winner here with the extra torque to get that pig on plane!
.1 I'm going merc and the fat heavy beast!
Bob 430 all the way. Or just drop a pitch and get that baby to jump on plane when now seeing that we don't care about top end!

There are no numbers published for Merc yet. On the Volvo side, what, in your opinion is the argument in favour of the 430?

It sounds better than 380!
Bigger is better! Or largest available as they say.
I think surf it makes sense to have the extra hp. But that 380 has it going on for some reason even though every bit of the engines are the same? 1 while second quicker that's a big deal. The gear ratio is diff on the 430. Drop a pitch it will be a stump puller? Program only thing diff? Still not sure I buy that but yes I know all parts show are the same. R7 had a different pitch prop from 380 to 430
Myself I would go down a pitch if I didn't think it was good enough. But this r6 time to plane is terrible. With less dead rise it was supposed to be better not worse. Goes to show how much weight they added.
I would wait to see what the merc shows. It might be worth the wait.
Honestly right now that 380 is the choice going by charts.
Again I sure wish we had a side by side real life comparison.

[bruceb58]

So...very interesting! I posted in another thread why it was weird that the spec weight of the R5 was 1000# less than the R6. These numbers show them pretty close.

[tgrace98]

Bob where is the merc prop chart? I think the 430 8.2HO is going to be the winner here with the extra torque to get that pig on plane!
.1 I'm going merc and the fat heavy beast!
Bob 430 all the way. Or just drop a pitch and get that baby to jump on plane when now seeing that we don't care about top end!

There are no numbers published for Merc yet. On the Volvo side, what, in your opinion is the argument in favour of the 430?

It sounds better than 380!
Bigger is better! Or largest available as they say.
I think surf it makes sense to have the extra hp. But that 380 has it going on for some reason even though every bit of the engines are the same? 1 while second quicker that's a big deal. The gear ratio is diff on the 430. Drop a pitch it will be a stump puller? Program only thing diff? Still not sure I buy that but yes I know all parts show are the same. R7 had a different pitch prop from 380 to 430
Myself I would go down a pitch if I didn't think it was good enough. But this r6 time to plane is terrible. With less dead rise it was supposed to be better not worse. Goes to show how much weight they added.
I would wait to see what the merc shows. It might be worth the wait.
Honestly right now that 380 is the choice going by charts.
Again I sure wish we had a side by side real life comparison.

The merc motor is a lot heavier than the vp motor. Around 750lbs I believe. Wouldn’t it then be slower than the vp? It was in the last generation r series.

[Big Block Power]

There are no numbers published for Merc yet. On the Volvo side, what, in your opinion is the argument in favour of the 430?

It sounds better than 380!
Bigger is better! Or largest available as they say.
I think surf it makes sense to have the extra hp. But that 380 has it going on for some reason even though every bit of the engines are the same? 1 while second quicker that's a big deal. The gear ratio is diff on the 430. Drop a pitch it will be a stump puller? Program only thing diff? Still not sure I buy that but yes I know all parts show are the same. R7 had a different pitch prop from 380 to 430
Myself I would go down a pitch if I didn't think it was good enough. But this r6 time to plane is terrible. With less dead rise it was supposed to be better not worse. Goes to show how much weight they added.
I would wait to see what the merc shows. It might be worth the wait.
Honestly right now that 380 is the choice going by charts.
Again I sure wish we had a side by side real life comparison.

The merc motor is a lot heavier than the vp motor. Around 750lbs I believe. Wouldn’t it then be slower than the vp? It was in the last generation r series.

Tank im thinking the torque is going to help with the extra weight. That's my thought. Heck with top end on these. They won't be a rocket! My bb could care less how much weight it's pushing.

[Big Block Power]

Bob where is the merc prop chart? I think the 430 8.2HO is going to be the winner here with the extra torque to get that pig on plane!
.1 I'm going merc and the fat heavy beast!
Bob 430 all the way. Or just drop a pitch and get that baby to jump on plane when now seeing that we don't care about top end!

There are no numbers published for Merc yet. On the Volvo side, what, in your opinion is the argument in favour of the 430?

BBP's argument for the 430? Simple. It's the largest engine option in your list.

And just for Jeef because it's the largest!
They wouldn't charge more if it was the worst option!

[BobRae99]

Bob where is the merc prop chart? I think the 430 8.2HO is going to be the winner here with the extra torque to get that pig on plane!
.1 I'm going merc and the fat heavy beast!
Bob 430 all the way. Or just drop a pitch and get that baby to jump on plane when now seeing that we don't care about top end!

There are no numbers published for Merc yet. On the Volvo side, what, in your opinion is the argument in favour of the 430?

It sounds better than 380!
Bigger is better! Or largest available as they say.
I think surf it makes sense to have the extra hp. But that 380 has it going on for some reason even though every bit of the engines are the same? 1 while second quicker that's a big deal. The gear ratio is diff on the 430. Drop a pitch it will be a stump puller? Program only thing diff? Still not sure I buy that but yes I know all parts show are the same. R7 had a different pitch prop from 380 to 430
Myself I would go down a pitch if I didn't think it was good enough. But this r6 time to plane is terrible. With less dead rise it was supposed to be better not worse. Goes to show how much weight they added.
I would wait to see what the merc shows. It might be worth the wait.
Honestly right now that 380 is the choice going by charts.
Again I sure wish we had a side by side real life comparison.

I'm not sure what gear ratio you are referring to. From the chart, it looks like both have 2.32 gearing and the same props.

I wish we could see the torque curves for both engines (380/430). Maybe the 430 has more torque available down low, but if it did, then why isn't it getting on plane quicker?

I suppose there is value in waiting for the Mercruiser numbers but it seems to me that both manufacturers seem to have similar power from their powerplant

Perhaps when Cobalt tells me the best engine for the boat is the 380, maybe they know something? They know me already and know this would be my 3rd boat in 4 years so I don't think they'd be down selling me in engine size to make the price more appealing. Maybe they think if I spend less on engine I'll spend more on Cobalt options that they have more margin on?

I could have had a bit more speed with a 380 in my current boat, but the 350 has provided plenty of power and decent speed @ 51 mph and I doubt spending an extra $5,000 was going to get me even half that back on trade.

The whole thing is a mystery.

[tgrace98]

There are no numbers published for Merc yet. On the Volvo side, what, in your opinion is the argument in favour of the 430?

It sounds better than 380!
Bigger is better! Or largest available as they say.
I think surf it makes sense to have the extra hp. But that 380 has it going on for some reason even though every bit of the engines are the same? 1 while second quicker that's a big deal. The gear ratio is diff on the 430. Drop a pitch it will be a stump puller? Program only thing diff? Still not sure I buy that but yes I know all parts show are the same. R7 had a different pitch prop from 380 to 430
Myself I would go down a pitch if I didn't think it was good enough. But this r6 time to plane is terrible. With less dead rise it was supposed to be better not worse. Goes to show how much weight they added.
I would wait to see what the merc shows. It might be worth the wait.
Honestly right now that 380 is the choice going by charts.
Again I sure wish we had a side by side real life comparison.

I'm not sure what gear ratio you are referring to. From the chart, it looks like both have 2.32 gearing and the same props.

I wish we could see the torque curves for both engines (380/430). Maybe the 430 has more torque available down low, but if it did, then why isn't it getting on plane quicker?

I suppose there is value in waiting for the Mercruiser numbers but it seems to me that both manufacturers seem to have similar power from their powerplant

Perhaps when Cobalt tells me the best engine for the boat is the 380, maybe they know something? They know me already and know this would be my 3rd boat in 4 years so I don't think they'd be down selling me in engine size to make the price more appealing. Maybe they think if I spend less on engine I'll spend more on Cobalt options that they have more margin on?

I could have had a bit more speed with a 380 in my current boat, but the 350 has provided plenty of power and decent speed @ 51 mph and I doubt spending an extra $5,000 was going to get me even half that back on trade.

The whole thing is a mystery.

What bbp was referring to is the 380 uses the 2.32 gear ratio and the 430 is a 2.14. So a wider gear would explain why the 430 takes longer to plane.