We made another dyno pull today and the engine ran great as usual.
Made 1734 ft lbs torque and 1742 HP @ 5275 rpm.
We ran into a limitation of the size of the exhaust pipe from the engine going through the wall. From the 4" pipes on the turbos it run's 8' and necks down to 3 1/2 " going through the wall. That made significant back pressure over the boat installation where the 4" pipe is only 16" long.
This dyno was only good for 850 hp before all the recent upgrades he did so backpressure was never a concern before.
In the boat the highest back pressure I ever showed on the gauge was
22 1/2 # @ 7800 rpm @ 27# boost.
On the dyno the back pressure was up to 40# @ 5250 rpm.
We stopped there until a future date when the pipe size can be increased.
With a back pressure problem the law of diminishing return applies.
I would speculate that the HP with less back pressure and at the 7800 rpm I ran it this summer was somewhat higher.
I figured it made a good enough show for a ski boat engine as it was
Here's the video,
It was pretty impressive to hear the turbos scream when he loaded it down with 100% throttle at 3000 rpm.
I forgot to put a piece of tape over the mic hole on the video camera so the sound about goes blank when it got real loud.
I couldn't believe how red the pipes got.
I guess it seems a little absurd that we used this for so much water skiing and tubing this year.
Rode 4 of us and my granddaughter in the boat for hours. She fell asleep in the back seat.