XD9000i VS M8000 Help me understand

[RockMonkey]

I'm just trying to understand why the XD900i is rated at 9000 pounds and the M8000 is rated at 8000. To my thinking there are three major foctors that would determine pulling power:
1. motor horsepower
2. gear ratio
3. drum diameter

You can get more pulling power by increasing motor horsepower, lowering the gear ratio (numerically higher), or decreasing the drum diameter (although strength would quickly become an issue). There could be differences in friction I suppose, but those are the major factors, right? Well, the M8000 has a higher horsepower motor than the XD9000i (4.8 HP VS 4.1), a lower gear ratio (216:1 VS 156:1), and they both have a 2.5" drum. So I don't get it. Shouldn't the M8000 be producing more pulling power than the XD9000i?

 

[Kiel]

Maybe it has something to do with the type of motor it is or how it is wound. Like series wound etc

 

[RockMonkey]

Maybe it has something to do with the type of motor it is or how it is wound. Like series wound etc

They are both series wound.

 

[BCGPER]

Assuming both motors are rotating the same rpm (I used 1200 as a guess), the 8000 pound unit is capable of 4500 ft. lbs. of torque, while the 9000 pound is only capable of 3000. My best guess would be the motor on the 8000 pound model is turning quite a bit faster than the 9000. If the 8000 pound model were turning 1800 RPM, the winch would be capable of 3000 ft. lbs of torque.

If you can get the motor speeds (or drum speed), then you'll know for sure.

 

[RockMonkey]

Assuming both motors are rotating the same rpm (I used 1200 as a guess), the 8000 pound unit is capable of 4500 ft. lbs. of torque, while the 9000 pound is only capable of 3000. My best guess would be the motor on the 8000 pound model is turning quite a bit faster than the 9000. If the 8000 pound model were turning 1800 RPM, the winch would be capable of 3000 ft. lbs of torque.

If you can get the motor speeds (or drum speed), then you'll know for sure.

Isn't RPM calculated into the horse power figure?

 

[Paul R]

They are both series wound.

It looks like the XD9000i has a lower amp draw at similar weights... Maybe that has something to do with it... @ 24VDC the 9000 also has a higher HP rating.

 

[RockMonkey]

It looks like the XD9000i has a lower amp draw at similar weights... Maybe that has something to do with it... @ 24VDC the 9000 also has a higher HP rating.

How many people are running these at 24 volts?

 

[Maverick]

Electric motors have a HP rating at a given speed, thus you can have an 1150rpm motor and an 1800rpm motor, both with the same HP, but the 1150rpm motor has more torque (to produce that HP at the lower rpm)

HP=tq x rpm / 5252

Any idea what rpm the motors are? Line speeds?

My lowly M8000 has pushed a few rigs out of my way, and helped out one or two others in a pulling capacity as well. On a couple of occasions, by unloading the spool of the heavy wire rope, I was able to lighten up the weight enough to simply drive out of the situation. Of course, I spooled the cable in so that I wouldn't drive over it.

 

[Paul R]

How many people are running these at 24 volts?

I don't think many, but it was a difference...

 

[RockMonkey]

Okay, here is the line speed for each winch:

M8000

XD9000i

BC, Brett, can you translate that into something that pertains to this discussion? The M8000 has faster line speeds across the board. Since it's geared lower, and has the same drum diameter, that must mean the motor is turning faster RPMs, right? So is it under-rated as an 8000 pound winch? Is the XD9000i over-rated? The deeper I look at this, the more the M8000 looks like a better winch, and for way less money.

 

[SAMI]

it definately would look as though the M8000 pulls faster w/ less amps.. well, sorta less amps.. inbetween Warns 8 & 9K

 

[RockMonkey]

I'm no math whiz, but I'll give the RPM problem a shot.

The layer of rope would make a difference on line speed, but I'll calculate based on the first layer. The drum size is 2.5" diameter. That makes the circumference 7.853981633974483". We'll just say 7.9 inches.

M8000:
42 feet per minute converts to 504 inches per minute. Divided by 7.9 (inches per drum revolution) = 63.8ish drum revolutions per minute. Multiply that by the gear ratio (216) = 13789 motor RPMs.

XD9000i
38 feet per minute is 456 inches per minute. Divided by 7.9 inches per drum revolution = 57.7ish drum revolutions per minute. Multiplied by the gear ratio (156) = 9004 motor RPMs.


Okay, so these numbers seem way too high, given the estimates BC used. What did I do wrong? Maybe I should re-run the calculation based on the third layer of rope, or something. The XD9000i is definately turning lower RPMs though, which makes it a higher torque motor. Does that account for the whole discrepancy?

 

[Paul R]

it definately would look as though the M8000 pulls faster w/ less amps.. well, sorta less amps.. inbetween Warns 8 & 9K

Actually if you look at the same weight the 8000 has a higher amp draw than the 9000...

 

[RockMonkey]

Actually if you look at the same weight the 8000 has a higher amp draw than the 9000...

I don't think he understands that these are both Warn winches either.

 

[BCGPER]

Something wrong with you math there big feller. If your motor is spinning 13,000 RPM, then your drum would be turning 6400 RPM (2.16:1). I'd go over your math, but I've already got a headache.

From just looking at your chart, I'd lean toward the 9000 pound unit for the simple fact it's not working as hard (amps) at the same pull as the 8000 pound model. Lower current draw usually means longer life of the winch, not to mention the battery and alternator.

Personally. I'd go with the slower line speed as well. One thing I don't like about my 9500TI is how damn fast it is. Cool, if you're in a competition, but bad if you're just trying to nudge something, or just put a little pressure on your line.

 

[RockMonkey]

Something wrong with you math there big feller. If your motor is spinning 13,000 RPM, then your drum would be turning 6400 RPM (2.16:1). I'd go over your math, but I've already got a headache.

From just looking at your chart, I'd lean toward the 9000 pound unit for the simple fact it's not working as hard (amps) at the same pull as the 8000 pound model. Lower current draw usually means longer life of the winch, not to mention the battery and alternator.

Personally. I'd go with the slower line speed as well. One thing I don't like about my 9500TI is how damn fast it is. Cool, if you're in a competition, but bad if you're just trying to nudge something, or just put a little pressure on your line.

But according to Warn's web site the planetary gear ratio is not 2.16:1, it's 216:1. That makes the drum spin at 60 RPM at 13000 motor RPMs.

 

[RockMonkey]

Here are the specs as shown on Warn.com

216:1 planetary.

 

[Maverick]

Winch Speed Load DrumRPM Ratio MotorSpd ActualHP Actual Tq
M8000 8.01 8000 12.2 216 2643.5 3.9 1.94

M8000 16 2000 24.4 216 5280.4 1.0 0.97

M8000 42 0 64.2 216 13861.0 0.0 0.0

XD9000i 6.88 8000 10.5 156 1639.9 5.3 1.67

XD9000i 14.4 2000 22.0 156 3432.2 1.3 0.87

XD9000i 38 0 58.1 156 9057.3 0.0 0.00


More or less...I had to delete a bunch of stuff...but basically the XD has a higher torque motor.

I like the higher speed of an 8274 when using the winch to help climb something. I can easily overrun my M8000. But between the M8000 and the XD9000...I'd take the M8000.

I hope the formatting on this turns out. (5th try)

 

[RockMonkey]

You can buy 2.3 M8000s for the price of an 8274, and they both say Warn on them.

So, we may not have nailed down the exact motor RPM, but we have determined that the XD9000i motor spins slower than the M8000. Is there a formula for figuring the line pull given the information we know? I'm still not convinced the XD9000i is going to pull 1000 pounds harder than the M8000.

 

[BCGPER]

Hey, I told ya I was tired.

How much cable does the 9K unit hold? I noticed the 8K one was only 80'. I think mine is 125', and that extra reach could come in handy some day.

Did you get the e mail from Carl? That one might just be worth a try, for the money.

But according to Warn's web site the planetary gear ratio is not 2.16:1, it's 216:1. That makes the drum spin at 60 RPM at 13000 motor RPMs.