MDC Drive Guardian Update- One Year Later.
11-16-2014, 10:23 AM
#41
Correct, the SSM version will fit virtually any transmission / drive combination. We would need to check the input shaft specifications of the MG502 to see if they are the same as a Borg Warner 72C. If not, then we would need a custom damper plate. We also have a shaft mounted version that might be an option for you as well depending on your power levels.
Mike
Mike
11-16-2014, 11:28 AM
#42
Registered
iTrader: (3)
Its not always the engine's power output at the flywheel that breaks drives, shafts, etc. For many years we've all associated that XXX HP is too much for XXX drive, or we've said things like, "an XR is fine behind a 525EFI",
Each boat setup is different. Speed factors in, water conditions factor in, prop blade count, diameter, slip factor, weight of the boat, all factor in. If flywheel HP was the only definitive of breaking drives, we would never have the scenerios like,
Guy #1 "Well I got 100 hours out of my XR drive behind my 525 before it broke",
Guy #2 "well I got 300 hours from my XR behind my 525 before it broke"
The flywheel output is the same, but that doesnt mean that the drivetrain is seeing the same torque levels. I think its been proven, that say a stock XR drive, can take 525 merc flywheel output. What the XR can't take, is the output from the water twisting the prop backwards. Think of the water as an engine, and the propeller as a the flywheel. At any moment you allow the water (engine) to grab and twist that prop, your actual engine's output becomes irrelevant. That scenerio, can easily supercede your engines flywheel output many times over, which Mike has validated during his development.
If we all had the same hull combo, the same props, the same engines, the same water conditions, maybe, you can get remotely close to what actual flywheel torque level XXX drive can handle. But with so many variables, its simply not possible to establish that number in my opinion. The ONLY constant we have, is the power the engines make. Anything else, we have no control over, as far as what loads the drivetrain will see while in operation. Hull weight, prop style, blade count, slip, speed, and so on. Until now that is. With the Drive Guardian, you now are able to control the maximum torque the drivetrain will see, which will be very relative to the engines flywheel output.
11-16-2014, 12:00 PM
#43
Inertia!
Engine spins up when leaving the water and then the prop catches again and has to "pull" the engine rpm back down. Result, higher torque than engine rated output. Another scenario is a simple shift directly between reverse & forward or forward and reverse. Two issues: 1) prop may not have stopped turning in one direction before it is reversing direction, 2) the engine unloads briefly between gears and the engine rpm raises above idle. Combine the two and the torque can easily be higher than rated engine torque.
Engine spins up when leaving the water and then the prop catches again and has to "pull" the engine rpm back down. Result, higher torque than engine rated output. Another scenario is a simple shift directly between reverse & forward or forward and reverse. Two issues: 1) prop may not have stopped turning in one direction before it is reversing direction, 2) the engine unloads briefly between gears and the engine rpm raises above idle. Combine the two and the torque can easily be higher than rated engine torque.
11-16-2014, 01:24 PM
#44
Gold Member
Gold Member
The way I look at it, and Mike please correct me if I am wrong on any of this, is that
Its not always the engine's power output at the flywheel that breaks drives, shafts, etc. For many years we've all associated that XXX HP is too much for XXX drive, or we've said things like, "an XR is fine behind a 525EFI",
Each boat setup is different. Speed factors in, water conditions factor in, prop blade count, diameter, slip factor, weight of the boat, all factor in. If flywheel HP was the only definitive of breaking drives, we would never have the scenerios like,
Guy #1 "Well I got 100 hours out of my XR drive behind my 525 before it broke",
Guy #2 "well I got 300 hours from my XR behind my 525 before it broke"
The flywheel output is the same, but that doesnt mean that the drivetrain is seeing the same torque levels. I think its been proven, that say a stock XR drive, can take 525 merc flywheel output. What the XR can't take, is the output from the water twisting the prop backwards. Think of the water as an engine, and the propeller as a the flywheel. At any moment you allow the water (engine) to grab and twist that prop, your actual engine's output becomes irrelevant. That scenerio, can easily supercede your engines flywheel output many times over, which Mike has validated during his development.
If we all had the same hull combo, the same props, the same engines, the same water conditions, maybe, you can get remotely close to what actual flywheel torque level XXX drive can handle. But with so many variables, its simply not possible to establish that number in my opinion. The ONLY constant we have, is the power the engines make. Anything else, we have no control over, as far as what loads the drivetrain will see while in operation. Hull weight, prop style, blade count, slip, speed, and so on. Until now that is. With the Drive Guardian, you now are able to control the maximum torque the drivetrain will see, which will be very relative to the engines flywheel output.
Its not always the engine's power output at the flywheel that breaks drives, shafts, etc. For many years we've all associated that XXX HP is too much for XXX drive, or we've said things like, "an XR is fine behind a 525EFI",
Each boat setup is different. Speed factors in, water conditions factor in, prop blade count, diameter, slip factor, weight of the boat, all factor in. If flywheel HP was the only definitive of breaking drives, we would never have the scenerios like,
Guy #1 "Well I got 100 hours out of my XR drive behind my 525 before it broke",
Guy #2 "well I got 300 hours from my XR behind my 525 before it broke"
The flywheel output is the same, but that doesnt mean that the drivetrain is seeing the same torque levels. I think its been proven, that say a stock XR drive, can take 525 merc flywheel output. What the XR can't take, is the output from the water twisting the prop backwards. Think of the water as an engine, and the propeller as a the flywheel. At any moment you allow the water (engine) to grab and twist that prop, your actual engine's output becomes irrelevant. That scenerio, can easily supercede your engines flywheel output many times over, which Mike has validated during his development.
If we all had the same hull combo, the same props, the same engines, the same water conditions, maybe, you can get remotely close to what actual flywheel torque level XXX drive can handle. But with so many variables, its simply not possible to establish that number in my opinion. The ONLY constant we have, is the power the engines make. Anything else, we have no control over, as far as what loads the drivetrain will see while in operation. Hull weight, prop style, blade count, slip, speed, and so on. Until now that is. With the Drive Guardian, you now are able to control the maximum torque the drivetrain will see, which will be very relative to the engines flywheel output.
11-16-2014, 05:25 PM
#45
Registered
We installed a Drive Guardian in a 30 foot Sutphen with a 950 HP blower engine. Max torque was 1100 ft. lbs. We completed two races,two poker runs and several trips to Marthas Vineyard. The drive is max machine upper with an IMCO lower. Saris pulled his drives apart last week . We are checking ours this week.
11-16-2014, 06:04 PM
#46
Registered
iTrader: (3)
Join Date: Aug 2007
Location: Sandown, NH - Sebago Lake Region, ME
Posts: 2,960
Likes: 0
Received 7 Likes
on
7 Posts
Correct, the SSM version will fit virtually any transmission / drive combination. We would need to check the input shaft specifications of the MG502 to see if they are the same as a Borg Warner 72C. If not, then we would need a custom damper plate. We also have a shaft mounted version that might be an option for you as well depending on your power levels.
Mike
Mike
Freedom - I believe the spline on the BW and MG are the same!
Can someone please PM me a price?
Thanks
Jim
Racer
