Volvo D9 575 - Full revs / fuel usuage real world

[Omegaelite]

When I was looking on internet and forum I struggled to find any data on what my boat with Volvo D9-575 would use fuel wise and what to expect from it cruising and WOT in the real world.

Had RK marine out yesterday with me on my fairline targa 47 doing to official Volvo "sea trial" where they tag all the data and send it to Volvo for analysis.

Attach the full report which shows fuel usage.

I had some issues with boat only reaching 26-28 knots, and after coppercoat, polished props and some engine work it now tops out at 33 knots (although only managed 32 on the sea trial) and cruises at 24-26. It was a bit calmer today and we managed 34 in it.

Hope you find it useful.

View attachment ESCAPISM.pdf

 

[[2068]]

I think they were doing you a disservice by categorising a T47 as a "Lager Sport Cruiser".
Is Brunello Di Montalcino not allowed?

Other than that, I would be happy with 34 kts.
Interesting report.

.

 

[petem]

When I was looking on internet and forum I struggled to find any data on what my boat with Volvo D9-575 would use fuel wise and what to expect from it cruising and WOT in the real world.

Had RK marine out yesterday with me on my fairline targa 47 doing to official Volvo "sea trial" where they tag all the data and send it to Volvo for analysis.

Attach the full report which shows fuel usage.

I had some issues with boat only reaching 26-28 knots, and after coppercoat, polished props and some engine work it now tops out at 33 knots (although only managed 32 on the sea trial) and cruises at 24-26. It was a bit calmer today and we managed 34 in it.

Hope you find it useful.

View attachment 57881

Thanks for posting this. The interesting thing is the virtually flat l/nmi once on the plane. When we were at the factory last month, Martin Hicks who used to do all the testing at Ipswich mentioned that they've seen similar figures when testing models in the past. So those people pootling to save money, have been literally wasting their time!

When I eventually get my boat (come on someone, £30 down and we can be on be water for the summer), I'd like to get similar tests done.

 

[Portofino]

Interesting
Few comments -----

No EGT ? Can understand if no sensor fitted ,but can be usefull to access real world cruise speed balance agianst thrashing the engines .

Load above 27 knots circa 88-90 % kinda doable .That's with a clean bum + sterngear !
Anything over 90% or 100% I my view stay out of there -if the boats a keeper .
What's your ave cruise RPM ? Guess should be 2200 rpm -26knots -with sterngear fouling 24-25 for mid season .-but load due to fouling will push over 90% ----erh em ?
Which is where you were in the T47post ( Volvo Paul )

Suggestive to me that the D9 -T47 package is just --- depends if your glass is 1/2 full or 1/2 empty
Is either
1- under powered in the real world -fine at magazine demo -clean /new/light /calm sea etc
2- Or spot on ? Supposed to cruse @ 24-25 -was designed for that ? Which is what you have ,so what?

Temp @ 88 oC looks high (sea temp 12) -I,am running 84 sea temp 18 now ,risers to 86 in the summer sea temp 25/26.In the Med ,so interesting to see temp in the Med in that boat ? Add another 2+oC taking it over 90 --- !

There's 3 T47's on my quay and two owners have complained -well struck up a conversation - exactly what you say mid season struggling to go over 26/27 .Knots flat out .-cruise @22-24 K
Reason I know this they have to walk past my boat and have struck up a conversation after I have "ghosted" by them -overtaken them last Summer .in the low thirties knots .

Torque 1650 Nm ,another 400 taking it past 2000 would be nice to allow via gearbox ratio and or bigger prop pitch for a 7+ knot tick over = just the extra oomph you need
AMHO
There's a similar post about this seemingly taboo subject -boat engine power / load/stress .
http://www.ybw.com/forums/showthrea...sel-engine-revs-at-max-load-Governor-or-props

 

[jimmy_the_builder]

Thanks for posting this. The interesting thing is the virtually flat l/nmi once on the plane. When we were at the factory last month, Martin Hicks who used to do all the testing at Ipswich mentioned that they've seen similar figures when testing models in the past. So those people pootling to save money, have been literally wasting their time!

When I eventually get my boat (come on someone, £30 down and we can be on be water for the summer), I'd like to get similar tests done.

Your comment about pootling is completely wrong, Pete - pootling is about running the boat no faster than hull speed, at which point it is using way less fuel than at any planing speed. You can see this in OE's pdf report; I see exactly the same behaviour on my T40.

 

[Omegaelite]

Ive seen boats down the med run all day long literally at WOT, ive been on them where the owner just likes to blast all day....doesnt seem to do them any harm. Ive test deiven the nee targa 48 and by comparison was underpowered and needed quite a blip of throttle to move and was really straining at 31 knots with a clean hull and no jet ski due to the pod drives. The d11 670 would have been the prefect engines for the targa 47 which i know a few of the med boats had, cruise at 28 wot at 39. But its always a compromise buying a used boat. Were looking at moving up to the targa 50 and would definetly have the bigger 670 engines on whatever we buy.

 

[kashurst]

thanks for posting that info - Those figures are remarkably similar to my D9 575s. I am about 1 to 2 kns slower in the 20knt + speed range , but I think my boat is a bit bigger and a bit heavier so probably slightly different props. I find in the summer I loose top speed as the sea water can be 32 degs C. It drops from 30 (winter) to 28(summer). With a clean bottom I tend to run around at @ 23 knts. or pootle at 8 knts

 

[Portofino]

Ive seen boats down the med run all day long literally at WOT, ive been on them where the owner just likes to blast all day....doesnt seem to do them any harm. Ive test deiven the nee targa 48 and by comparison was underpowered and needed quite a blip of throttle to move and was really straining at 31 knots with a clean hull and no jet ski due to the pod drives. The d11 670 would have been the prefect engines for the targa 47 which i know a few of the med boats had, cruise at 28 wot at 39. But its always a compromise buying a used boat. Were looking at moving up to the targa 50 and would definetly have the bigger 670 engines on whatever we buy.

Yup that's a good rule of thumb knock off 8-10 knots of WOT for real time cruise .

WOT -that's defined as 1/2 fliuds,, new ,calm sea ,clean bottom ,polished props ,no wind etc
Real time cruise -defined as -mid season fouled hull+ props a bit, 1M waves , head wind 15 knots, tender , 80% fliuds,excess cruising stores , high ambient air temp ' high sea temp , rough layers /years of antifoul etc .

Some builders offer a chiose eg Portofino 53 -CAT C12 700hp - VP D12 - 715 hp or MAN R6 800,s -I think in the Med if poss I know it cost more especially new but if poss Allways go for the bigger arguably better engine option .
I think they intall a smaller one to get the sticker /mag / headline price where it need to be to lure a buyer .
Once hooked along with options then maybe try to up sell the bigger motors ?

 

[Portofino]

Thanks for posting this. The interesting thing is the virtually flat l/nmi once on the plane. When we were at the factory last month, Martin Hicks who used to do all the testing at Ipswich mentioned that they've seen similar figures when testing models in the past. So those people pootling to save money, have been literally wasting their time!

Poolting is going 0.1 of a knot below max D speed ,as Jimmy says .Any faster it starts to push a bow wave and burns fuel .
Max D depends on WL length .
I can go at 36 L/ H ( total ) at 9 knots -with 2200 L -that's a long time .
In the Med with time on your hands to do 100 miles say two chioses
1- get up a 6 am cruise @ 27 knots Eco 180 L/H arrive 9 am -anchor = boredom sets in -or
2- Leave at 9 am after a leisurely breakfast and Pootle - arrive @ 7pm 10 hrs later after enjoying the trip only using 350 L or so .
Or a combo of both in realality
(BTW 32 knots 88% load is 230 L/H )

 

[Latestarter1]

When I was looking on internet and forum I struggled to find any data on what my boat with Volvo D9-575 would use fuel wise and what to expect from it cruising and WOT in the real world.

Had RK marine out yesterday with me on my fairline targa 47 doing to official Volvo "sea trial" where they tag all the data and send it to Volvo for analysis.

Attach the full report which shows fuel usage.

I had some issues with boat only reaching 26-28 knots, and after coppercoat, polished props and some engine work it now tops out at 33 knots (although only managed 32 on the sea trial) and cruises at 24-26. It was a bit calmer today and we managed 34 in it.

Hope you find it useful.

View attachment 57881

Thank you for posting, the fuel burn #'s look pretty close to published VP data using 2.5 exponent. I will be curious to see what V.P. make of the numbers, surprised the dealer carrying out the trial made no comment about the #'s.

I have a project on the go to build a sea trial data logger for sea trials which will store data on raspberry Pi and I would have been interested to see EGT rise from 2,400 rpm to rated speed.

Very interested to see how V.P. view a vessel propped 'right on the edge'.

 

[tetleys]

A great read and extremely informative having bought a Targa 47 with 575 D9,s in January this year.
Much appreciated

Tetleys

 

[volvopaul]

As far as I know ther has only been 1 D9 fail in catastrophic style and that was in a Targa 47, one which I serviced in the SOF . Later that season it failed big style. Boat was taken back to UK , engine removed for inspection.
The outcome was good for owner, it was fixed but while all was going on he traded up in size I believe.
The cause wasn't broadcast to the open world which is a shame as reading RK marines vodia sea trial report tells me that the props need a shave off the pitch to give the engines a chance should an owner end up the same way as the SOF boat.

Now surely I see it this way.
New boat design with any engine should have a full sea trial with EGT monitors fitted and passed off according to results, I'd be interested to conduct my own test should I buy a T47 with the said engines.

 

[Latestarter1]

As far as I know ther has only been 1 D9 fail in catastrophic style and that was in a Targa 47, one which I serviced in the SOF . Later that season it failed big style. Boat was taken back to UK , engine removed for inspection.
The outcome was good for owner, it was fixed but while all was going on he traded up in size I believe.
The cause wasn't broadcast to the open world which is a shame as reading RK marines vodia sea trial report tells me that the props need a shave off the pitch to give the engines a chance should an owner end up the same way as the SOF boat.

Now surely I see it this way.
New boat design with any engine should have a full sea trial with EGT monitors fitted and passed off according to results, I'd be interested to conduct my own test should I buy a T47 with the said engines.

Thank you Paul, exactly what I was alluding to.............

As you know I generally try and stay away from V.P threads as others far better informed however I have a thing about correctly performed sea trials so I was really looking for answers.

The V.P dealer has performed the sea trial, printed off the results has the taken Op's $$ and focus was on fuel consumption which one could pick up off the data sheet fuel curve but no advice from technicians carrying out the trial simply deferring to Volvo??

Question are V.P. dealers qualified to perform sea trial not qualified to interpret the results or are they gagged by some internal Volvo politics about commenting about production installations which are clearly wrong from the outset?

Considering that the vessel was 'fettled' prior to the trial the engine loading's recorded are scary and the top end consumption numbers also give a clue. What frightens me is the apparent misunderstanding of engines recording % engine load. Engine cannot scream for help when it being tortured by being overloaded by as much as 50% it can only continue to record 100%, said it time and time again loading is not linear it is by the propeller exponent, simply look at any propeller law curve and project it below the rated speed point and see the effect.

I only have Volvo D12 marine technical package but it is reasonable to assume that the electronic droop on all Volvo marine engines is close to isocronous and high idle is 40 to 70 rpm above rated engine speed i.e the governor break point, no different from other engine manufacturers.

General consensus across the industry is that electronic engines need to be propped to ensure that maximum engine load at rated speed is in the range of 92 to 97%, personally I prefer 92% to take account of the 'give em tight wire' owners.

Yes recording EGT would give a very clear indication that the engine installation is flawed and Volvo D9 G drive engines actually have pyrometer in the factory supplied turbo outlet flange however all of no avail if V.P. marine dealers are gagged from passing on their findings on installations which have been wrongly approved by the factory.

 

[baylabayla3288]

There seems to be quite uneven load between 1800 and 2200 rpm. What might be the reason for this? Did they use auto rpm synch during the trial? Interesting data, thanks for posting.

 

[petem]

Your comment about pootling is completely wrong, Pete - pootling is about running the boat no faster than hull speed, at which point it is using way less fuel than at any planing speed. You can see this in OE's pdf report; I see exactly the same behaviour on my T40.

Fair point, I should have said low planing speed.

 

[Latestarter1]

There seems to be quite uneven load between 1800 and 2200 rpm. What might be the reason for this? Did they use auto rpm synch during the trial? Interesting data, thanks for posting.

I would suggest vessel simply getting over the hump.

'Interesting data' terrifying would be a better description.

 

[baylabayla3288]

I would suggest vessel simply getting over the hump.

'Interesting data' terrifying would be a better description.

I was referring to the different load on port and starboard engine. Could be due to differences in the turbo performance. The boat should be over the hump at 19 knots /1800 rpm already which is when the load gets uneven.

 

[kashurst]

where are they getting engine load value from ? is it related to fuel burn actual v max fuel burn or is it from the Vodia box ?

 

[Latestarter1]

where are they getting engine load value from ? is it related to fuel burn actual v max fuel burn or is it from the Vodia box ?

The calculation is done in the engine ECU/ECU. Throttle sets desired governor engine speed, reads all engine sensor input perimeters and selects correct PWM signal value to provide correct degree of fueling to achieve the set rpm level. The engine power calibration table 'knows' the correct amount of fueling from the calibration look up table to achieve set engine rpm at that power output. The percentage of extra fuel required to achieve rpm set by the throttle expressed % engine load.

All diagnostic tools simply read live data from the ECU/ECM and have benefit of being able data log the live data.

Just noticed the comment regarding turbo performance.................Propellers move boats engines merely turn them, how many times have I said it! Data being recorded is what propeller is telling the engine governor not vice versa.

 

[Switch]

If I'm reading the report correctly she's burning 170+ Lts p/hour at 26knts - blimey!! that's scary. I didn't realise how expensive T47's are to run - that's double what my D6 350's burn at a similar speed.