Carver Owners Forum

I did a full range of testing recording fuel consumption, turbo boost, speed and RPM using the YDES gateway I just installed. I repeated runs 3 times and got readings from 1000 RPM up to 2500 RPM which was the max I could reach.
I started smoking between 1300 and 1900 RPM. At 1300 I was averaging 8.6kts, at 1900 I averaged 11.8kts.
From 2000 to 2500 I had not noticeable black smoke just a light brown haze. At 2500 I averaged 20.3kts.
Starting at 1300 RPM the turbo boost on my stbd engine started lagging behind the port engine, and the smoke from the stbd engine was much more pronounced. Fuel consumption was also higher on the stbd engine. Surprisingly at 2500 RPM the turbo boost and fuel consumption on both engines equalized - the readings trended like the stbd engine caught up, not the port engine declining. Fuel consumption at 1300 per engine was 4.7gal/hr. At 1900 it was 12.2 port/13.3stbd. At 2300 it was 17.6 port/18.6 stbd. At 2500 it was 26.6 on both engines.
On the last trial I checked the Racor differential gauge and the stbd engine was reading 13"Hg which was well in the red. That may have been limiting my upper end RPM, but I don't understand yet why at 2500 RPM the stbd engine performed better than it did below that. I'm still suspicious of the wastegate and may change one out. First step though was to change the Racor filter out. I will run again later this week and see how that change affects smoking and speed, and then change out the second stage filters as well and take some more readings.

Nice testing, impressing to get numbers that can really help diagnosis instead of just throwing parts and guessing.

Far from a diesel expert here.I will venture an observation though based on your excellent test results. If at 2500 the boat is well on plane then the loading will drop and that may be enough for the levelling out you are seeing. The stbd appears to be working harder based on the fuel and smoke.

Is there a trusted marine diesel mechanic out your way that could see your results ?

Edit...... one other question comes to mind......does your readout show throttle/demand so when the sticks are pushed forward you can tell if the demand is the same for both sides ?

That's a great question on the throttles and one that hadn't even occurred to me. Throttles are synced through the EDC and that should of course adjust engines to output equivalent RPMs. I'll have to pay attention to that next time I'm out and go to WOT. I will take her our tomorrow and see how taking the fuel filter issue out of the equation affects operation.
I'm assuming I'm getting up on plane around 1900-2000 RPM but the only very slight flat spot in the speed vs fuel consumption was between 1300-1400 RPM but otherwise GPM increased continuously throughout the range.