PTO Dyno

[jgendr]

Hey all, been reading lots of stuff here and lots of Ideas and great posts.

I have been into diesel trucks ever since I bought my 01 Dodge, I have admin'd a couple of website's on hotrodding our toy's. I have learned tons on how to juice up the dodges and such. We have get-togethers to see how our tinkerin has helped. I'm proud to say that my 01 dodge lay's down and impressive 535hp and 1132lbf of torque where the rubber meets the road and I get an impressive 23 mph on the highway. We certify these numbers on a big dyno machines at our events.

Now I'd like to try tweaking my yanny just to see what I can get. I have searched the web and have found a couple of pto dyno's on fleebay and some new ones too. these are the ones used in the Nebraska tests. I want to build one just for S & G's, ( because I like to play) and start some tweakin.

Here is my thoughts:

1. An old electric break utility trailer axel (for creating a load)
2. a 1000lb load cell (to measure the load)
3. a inductance transducer ( to keep track of RPM's)
4. A PTO shaft and slip clutch ( Just in case! LOL )
5. A data logger ( to log all that data for compairision )


Have any of you bright folks out there ever thought of trying this and if so Give me some of you thoughts and suggestions.

I want to show some real world results of what a little tweaking can net you and pass that info on to all! If I can conservatively double or triple the hp in my dodge I know these little power houses are capable of far more than they are built.

If you could get (Safely 10 - 20 - 30 more HP) out of your tractor wouldn't you want to know how? Heck the sled pullers can do it why can't we?

Thanks in advanced

JG

 

[bobodu]

Personally, I'd fear tearing up a drive line hooking a dyno to my PTO with a hopped up engine. Wheel slipping is one thing,but how would you calculate a safe slip on a PTO?

 

[jgendr]

Easy, you can calculate the slippage, by calculating your target hp and troque you are shooting for. Simple calcuations:

Torque = JM * rpm per second / 9.551
where JM represents the Polar Moment of Inertia of our inertia dyno's flywheel.

If we don't know the Polar moment of Inertia for the flywheel (and our flywheel has a constant thickness cross-section) we can calculate it with the formula:
JM = (W * r ^2) / 32.16 / 2
where W represents the flywheel weight in pounds and r is its radius in feet.
Once you have the torque, it is easy to calculate the horsepower with the standard formula:
Hp = Torque * rpm / 5252
Keep in mind that the rpm in the last formula must be the average rpm during the sampling period.

 

[dqdave1]

yah, that is what I thought !!!!!!!!!!!!!!!!!! whatever you just said???????????
You know more about dynos than I ever will. Maybe I need to stay a a Holiday Inn Express. I can turn the key on my New Holland and move the throttle for more power!

 

[jgendr]

ROFLMAO!!!!! Now that was funny!!!!!!


very simple, The axel will be used as th load, the break backerplate will be free floating and the load sensor will be set at 1 ft from center off the backer plate. the hub of the axel break will be hooked to the tractor via the pto shaft.

so that being said, as the tractor is set to pto speed (540) the hub rotates. as you apply an electrical current to the trailer break it starts to put a load on the pto. that load is measured by the load sensor in actual foot lb's of torque. as you apply more current to the break assembly more torque is required to overcome the force.

so if my tractor is rated at 28 hp at the pto the calculation looks like this:

28hp = torque * rpm / 5252
torque= 28hp * 5252 / rpm(540)
torque = (28*5252)/540
torque = 272.3 ft lb's



So theoretically adding a turbo at 5 - 7 lbs of boost, a litte more fuel, and a little more timing will give you aproximatlly 10 - 12 hp.

Adding 7 - 10 lbs of boost will = 15 - 20 hp, 10 - 15 lbs of boost and an intercooler could get you upwords of 30 + hp.

 

[zzvyb6]

Well the high road would require a computer, National Instruments A/D Card, maybe some software (Student version of Matlab or Excel), the load cell, tach and some conditioning amplifiers. A nice science project.

Taking the low road would take a water pump or generator, some maybe an adjustable resistance load. Use tractor rpm, and water pressure for indication of load and hp. Trailer brake is a good idea. Assume you mean to attach a moment arm onto it and measure the braking force. A grain platform scale can be used for this, too.

Any way to combine hobbies so you could buy a truck power absorber and use in on the tractor?

 

[SPYDERLK]

Here is my thoughts:

1. An old electric break utility trailer axel (for creating a load)
2. a 1000lb load cell (to measure the load)
3. a inductance transducer ( to keep track of RPM's)
4. A PTO shaft and slip clutch ( Just in case! LOL )
5. A data logger ( to log all that data for compairision )

If you could get (Safely 10 - 20 - 30 more HP) out of your tractor wouldn't you want to know how? Heck the sled pullers can do it why can't we?

Thanks in advanced
JG

Great list! Consider, to avoid heat problem:

1. 
   Lower a bushog into water.
   2. Is this a torsion/torque cell? That would work on the hog arrangement.
   4. Slip clutch only needed if hog locks up.

larry

 

[jgendr]

Well the high road would require a computer, National Instruments A/D Card, maybe some software (Student version of Matlab or Excel), the load cell, tach and some conditioning amplifiers. A nice science project.

Taking the low road would take a water pump or generator, some maybe an adjustable resistance load. Use tractor rpm, and water pressure for indication of load and hp. Trailer brake is a good idea. Assume you mean to attach a moment arm onto it and measure the braking force. A grain platform scale can be used for this, too.

Any way to combine hobbies so you could buy a truck power absorber and use in on the tractor?

Thanks ZZ;

That's more on the line of what I was thinkin. Eventually I would like to use some sort of Data aquisition system for more reliable results, however initally manual calculations will be used. Keeping in mind this is on the cheap just to prove concept and baseline readings for power mods.

Explain the power absorber to me, I'm not sure what you talking about. I'm open to all contributions, cause that's the way progress is achieved.

thanks

 

[SPYDERLK]

Explain the power absorber to me, I'm not sure what you talking about. I'm open to all contributions, cause that's the way progress is achieved.

thanks

Beating water or air is a good way to absorb power. Hence the suggestion to vary your load by lowering a bushog into water. Rev it up, set hydraulics to lower bh slowly, observe the power curve.
larry

 

[DRL]

How about mounting a big water pump like an irrigation pump so it came pivot a little, then stop it from pivoting with the scale. Slowly close a valve on the output of the pump and read torque on scale. Would not have to worry about heat like with the brakes.

DRL