PTO Dyno

[dieselgeek]

yes I do get 23 MPG's.

Are you reading that from the overhead console?

what's your combo. Is this an ISB or a 6BT motor? what chassis dyno did you use (I am guessing Dynojet?)

-scott

 

[Brad_Blazer]

I like the hydraulic pump idea with a load cell measuring torque. The pressure can be monitored for reference and even calibrated to indicate torque. Fluid can be run thru a radiator on the low pressure side. I probably have a rotary encoder in my pile of junk. The original disk brake idea is not bad either - certainly least expensive. It all depends on what is in your junk pile. A centrifugal pump might not be the best choice. They tend to spin easier at higher pressures as flow rate drops.

 

[dfkrug]

It all depends on what is in your junk pile.

That's the truth! I don't know what a rotary encoder is, but that sounds
like a good pile of junk.

 

[RonMar]

If I recall my reading correctly, when the first polaris nuke power plant was being developed and mocked up, they used a wet brake as their mechanical load. It basically had a garden hose flowing water over the brake assembly attached to the steam turbine gearbox to keep the brake assembly cool. A large disc brake with water cooling might work OK.

I think restricting the flow from a hydro PTO pump is the way to go, with the pump atached to a lever arm to give you a direct FT/LB reading. Very easy to control. I don't think I would bother with monitoring pressure and flow as the direct torque reading related to RPM is really what you are after for comparison anyway. You of course would need a large enough pump that the HP demand would exceed the tractors capacity to provide, before the max operating pressure was reached.

Whatever you use, it will have to be supported outboard of the PTO shaft to avoid side loading the PTO shaft. Any twisting of the lever arm would probably result in errors in the torque reading also.

 

[dfkrug]

I think restricting the flow from a hydro PTO pump is the way to go, with the pump atached to a lever arm to give you a direct FT/LB reading.

I don't see how or why you would attach the PTO pump to a lever arm and
how that gives you a torque measurement. If you want to use a lever arm
for torque measurement, then you are simply back to a driveshaft and brake,
with a lever to hold the brake.

A hyd pump with fixed and known volume that works against a variable
relief valve will dissipate this much power:
hp = pressure (psi) x flow (GPM)/1714
increase the RV pressure until the motor can no longer maintain the set
RPM and you have your PTO output.

 

[jgendr]

Man This is great, I love it when minds come together on a task!!!

xlr82v2: That is exactly what I was planning on doing, Do they Have any more info at that site that will explain the electronica setup, I couldn't find any

SPYDERLK: That is way cool, I thought I was the only one out there thinkin of this project!!! I love the turbo whine!!! I'm gonna build my own system from custome exhaust manifold to the turbo and down pipe to the exsisting muffler, or straight pipe it LOL


dieselgeek: 01 ISB, DD4's, HX40, 5'' from down pipe all the way out, Full blown Sun Coast ProLoc Tranny holley blue pusher pump, 3:54 gears! And I take all my reading from GPS. I know the overhead is about 20% higher than actual. What really Helps is the ProLoc Torque Convertor!!! Mine is a 91% so it's very tight! Major difference.


dfkrug: You Are exactly correct with your formula's and I was thinking of useing that idea, however, I started looking into purchasing a PTO Hydraulic Pump, And them suckers ain't cheap!!! $400 or better!!! And since I don't have one laying around that is kinda out of the picture! Unless someone Out the has one they would like to donate to the project ( LOL )

I do have the axels hear and most of the other stuff, What I do need is more info on the Data side. How to cheaply hook the load and tach to the computer. Some if that stuff is pricy too. Flee bay has some that I've been looking at.

Who Knows Maybe we can have a get together down in the South East and have a dyno and sled pulling day LOL That would be fun!!

 

[SPYDERLK]

I don't see how or why you would attach the PTO pump to a lever arm and
how that gives you a torque measurement. If you want to use a lever arm
for torque measurement, then you are simply back to a driveshaft and brake,
with a lever to hold the brake.

A hyd pump with fixed and known volume that works against a variable
relief valve will dissipate this much power:
hp = pressure (psi) x flow (GPM)/1714
increase the RV pressure until the motor can no longer maintain the set
RPM and you have your PTO output.

What you said in post #20 was right- calibration and some care is needed. The formula here is to calculate the hydraulic HP delivered by the pump. It does not tell you the amount of power it takes to drive the pump. It tells you the HP the pump is delivering to the point where the measurement is taken. Youd have to be careful in order to get good answers at different HPs. Pressure would have to be measured at the pump port for one thing, otherwise flow losses would cause an error from one flow setup to the next. Best measure torque and rpm on the input shaft.
larry

 

[California]

... We certify these numbers on a big dyno machines at our events. ... Now I'd like to try tweaking my yanny

Uh ... just take it to the event. Done!

If that's too simple ...
a pto pump needs to push against something. Measure that push directly, by jamming a bath scale between your towbar and a torque rod bolted to the pump. Load the pump down etc. Another poster mentioned the side loading, but I think the pto is designed to drive belts (all side load) at full output for the life for the tractor, so a minute's test shouldn't hurt it. You don't need a fancy tach. There's one on the tractor already.

But after tweaking it I think you will discover that weight, traction, is the real world limit on usability. Yanmars are already light, high horsepower tractors because their primary application is a big rototiller in the rice fields. So your efforts will increase pto output, but not have much effect on pulling ability since that corresponds to weight. Maybe it could run a bigger mower or tiller if that's what you are building it for.

You may find the output limit is defined by the cooling system's capacity, too. By the time you redesign that, you might as well have bought the next larger tractor where they designed all that in for you already.

If you go ahead - we want pictures!!!

 

[jgendr]

Oh Definately Pics will be posted!!!

I emailed the gentleman that built the pto dyno that was pposted earlier. I'm waiting on a responce..


I am planning on useing a turbo from an Mercedes Benz 300TD, I like it because uses a standard T3-T4 mount on the manifold and the exhaust outlet has a built in flex tube. The waste gate is adjustable for tuning purposes, you can set it as little as 5 psi and as much as 20 psi. I know I'll never get anywhere near the high end for frear of blowing the head gasket. If it does blow I will be talking to a Diesel god guy I know about O-Ringing the block or head and ARP Studs!!! With this done on the dodges we see reliable boost pressures in the neighborhood of 100 PSI. if i keep the boost down low I won't need an intercooler, but not ruling one out! HE! HE! HE!

 

[Treemonkey1000]

jgender I had sent you a PM the other day with some links to optical tachometers. I don't know if you did get that or not.Where I work we test a lot of Shimpo tach testers out but there are many out there. Running around the $80-200 range. They are kind of fun to play with. You can use them on other things besides the PTO. Fans and motors or tuning engines such as chainsaws or lawnmowers.


Optical Tachometer
Pocket Laser Tachometer
http://www.reliabilitydirectstore.com/Tachometer
Shimpo Instruments, Tachometers, Stroboscopes