Twins with Twins, Anyone?
- Thread starter kidturbo
- Start date
$100k rebuilds every 200hrs after you spend $150k up front, is about the wildest things I've ever heard of. Besides the 1550hp that is.. It has 20hr rebuild windows after just $200k down.
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These Crazy 1550-Horsepower Engines Cost $200,000 Each
Mercury Racing’s super heroic marine powerplants are works of machine art. And you can order them in green.
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Couple new videos for the up all night gear heads.. Last trip out before pulling the trans. Testing line pressure and shifting Rpm range. Something up with the shifts, and she doesn't like the sub 2000rpm range with big props hooked up...
Source: https://youtu.be/EuFKfK0_a58
Source: https://youtu.be/QGjjFO3WjIw
Starting to see where the supercharger with big turbo feeding it really makes sense for something like this... Such a wide range needed for power/torque application where a big single isn't really ideal for the low end torque needed. Twins would be better but you would have a lot more heat to deal with in the boat.
Yeah after spending the weekend with the only other idiot out there trying to push 13,000lbs or more 100+ mph across the water with sub 7.0L diesels, we realized someone needs to buy both boats, and then ya have one less idiot in the world...
His attempt of running compounds, big 40+ pitch props, without the two speed transmissions in a much faster hull is not yielding much better results. The compounds work, and he can get on plane, in a cloud of smoke after a mile or so.. Currently chasing piping issues between the turbos, cause off the shelf exhaust tubing doesn't last long when ya heat cycle it 1700F and back a few times over and over very long distance.
The blower sure would help matters below 2000R for me. And those intakes have the mounting rails on there already. But for now, my plan is do what the Cummins can't., SPIN SOME FREAKING R's TILL SHE'S ALL LIT UP, THEN SHIFT AND PUNCH IT!!!
His attempt of running compounds, big 40+ pitch props, without the two speed transmissions in a much faster hull is not yielding much better results. The compounds work, and he can get on plane, in a cloud of smoke after a mile or so.. Currently chasing piping issues between the turbos, cause off the shelf exhaust tubing doesn't last long when ya heat cycle it 1700F and back a few times over and over very long distance.
The blower sure would help matters below 2000R for me. And those intakes have the mounting rails on there already. But for now, my plan is do what the Cummins can't., SPIN SOME FREAKING R's TILL SHE'S ALL LIT UP, THEN SHIFT AND PUNCH IT!!!
can you not shift under power? could you make the ecm defuel under a shift to quicken up the process and keep on top of plane as well as stay on the turbo?
Yes that is the key. However that Flair onshift was pushing the engines to the 6000 RPM limiter. About like driving a Powerglide, with drag slicks, on a wet Road. It may be shifting at 6000 RPMs and 10 miles per hour, or 4500 RPMs at 50 miles per hour. Previously it would just blow the props loose on the shift. Now that's resolved, need to find why it's still jumping 1000 RPM in that gap between the shifts.
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how does the trans work? is it a two clutch system where one must release and the other engages or just the single clutch pack that is locking a planetary or drum up?
It's a drum planetary set up. Why we are trying to diagnose the flare. Either of the electronic valving isn't correct, or it's slipping the pack on engagement.
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Was going to attempt a test bench setup for the Transmissions before they go back in. However if I can add an external mag pick up to a V2, I can track output shaft against engine rpm to diagnose why / where they are flaring.
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Here is a good shift [disregard the misfire blips] where it stayed on plane at 2300r after shift. But you can see the 2sec flare where I pulled the throttles back, then jumped on again after the shift.
Starting shift RPM was 3600r, flared to 4200, hooked up again at 2300..
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Starting shift RPM was 3600r, flared to 4200, hooked up again at 2300..
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And like you said before, if it stays loaded up it would be fine but when it just revs without the load and then grabs it is game over. Really wish I was closer to you to help in person.
So paint the picture some more on the trans or if you have a parts diagram on it and oil diagram, might be able to understand better.
Is it utilizing a band to stop the spinning drum for high range and clutches to only direct forward/neutral/reverse (separate clutch pack than the burnt ones for reverse) or some other setup?
If it uses a band, how hot spotted was the drum? I assume band is in good shape? How much leverage can be applied to it and pressure?
If it’s not a band on the drum, I would assume it has to be a clutch to clutch style like an Allison where you will need a split sec of defuel to allow release and application to happen or you get the giant flare and no grab action because the torque is just overpowering but when you bring power down, it can grab and then hold once powered back up.
Can you do some runs with incremental increase of throttle but under constant duty as each shift is applied to find the point where the engine simply overpowered the application of the clutches? That would help for a quick defuel upon shifting and how fast the trans is actually shifting. Do you have a log of a good shift and how fast it is (one that doesn’t have blow through)?
Is it utilizing a band to stop the spinning drum for high range and clutches to only direct forward/neutral/reverse (separate clutch pack than the burnt ones for reverse) or some other setup?
If it uses a band, how hot spotted was the drum? I assume band is in good shape? How much leverage can be applied to it and pressure?
If it’s not a band on the drum, I would assume it has to be a clutch to clutch style like an Allison where you will need a split sec of defuel to allow release and application to happen or you get the giant flare and no grab action because the torque is just overpowering but when you bring power down, it can grab and then hold once powered back up.
Can you do some runs with incremental increase of throttle but under constant duty as each shift is applied to find the point where the engine simply overpowered the application of the clutches? That would help for a quick defuel upon shifting and how fast the trans is actually shifting. Do you have a log of a good shift and how fast it is (one that doesn’t have blow through)?
No instructions, no diagrams, like the rest of this project only exists in one person's head. Reason spent time with said head. LOL
In short, it's a Powerglide.
The shifting is done with a set of solenoid valve, One releasing after the other on the shift. We've been tested with air hose and they seem to be working correctly. Not sure if issue is clutches, or valving. Once I get it back together with some good sensors way will divulge into this one further.
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In short, it's a Powerglide.
The shifting is done with a set of solenoid valve, One releasing after the other on the shift. We've been tested with air hose and they seem to be working correctly. Not sure if issue is clutches, or valving. Once I get it back together with some good sensors way will divulge into this one further.
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10-4, so clutches are used to stop the drum from spinning and hit high gear.
Very interesting issue though!
Very interesting issue though!
We got the first IPS drives on the West coast back in the day when we were the Cruisers dealer at the time and the charger out of the hole until turbos made boost , then the clutch released the pulley for the charger worked pretty good, def a different setup though but it sure helped with the turbo lag so we could our 42' on plane right away and then the chargers dropped out while the turbos kept her up. have seen anybody try this setup in a go fast but i bet its out there
also sure glad we now have "LIKE" button !!!!!!!!!!
also sure glad we now have "LIKE" button !!!!!!!!!!
