Difference in Stators????

[JSmith]

Can someone explain the differences between the big four aftermarket stators in the tourqe converters, I want to know about the fluid coupling. Are they all about the same? I see some are exposed and others are not. Do they all just move right now without the high rpm to get motion? Unlike the factory unit that has to have 1800rpm to get along at a good pace. If you have one I would like to hear how it works.

 

[Piston Slapper]

This is one the MAJOR things that seperate the transmission builders. The importance of the stator (fluid coupling) and its design seems to vary from one to the other. I personally think this is the most important piece in the transmission. I assure you they are not all the same. Some just work better than others, meaning some work more efficiently... Its just so hard try'n to be objective about it without starting some transmission war.



I hope you brought your saddle with the Big Horn. This ought to be fun!

 

[Peter Campbell]

It is good I do not know the construction details of the converter makers. This is just an opinion. ( fill in other disclaimers ). The lock up converters mean that the design of the converter is less important now than back in the bad old days of non lockup slushboxes. I do know for drag racing the torque multiplication and stall speed are critical for good performance. Just milling some efficiency off of the blades of the converter parts only raises stall speed and not the efficiency ( torque multiplication etc. ) It can lower the efficiency. Milling flats on blades does not increase efficiency on a 1000MWE High pressure steam turbine, so I don't think the rules change in a oil pump, reversing blades, oil turbine application ( torque converter ). When a builder changes the stator design- if it is built from the drawing board up- then that will generally perform better than removing pieces of an existing design to get one number on its performance characteristics to change. On the design board you can "tune" the results to what you want. So the vendors who do thier homework and build converters can optimize thier transmission tune. Build it loose and use the lockup more? build it tight with ok torque multipication to minimize heat out of lockup? nothing is wrong with either way- if that is what their aim point is. Vendors who butcher an existing part and claim the "redesign" is an improvement are not being forthright in what thier improvemnet was.

 

[Bob Wagner]

When I put the gear selector in D , I am moving without the foot on the go pedal.



91% DTT set up



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[Floor It]

I am curious to what the multiplication factor is? The stock converter is around 1. 93, so what is DTT's compared to ATS?

 

[Edward]

I am not trying to confuse the issue any but some terms are being used a bit to loosely. Milling is far to general a term to convey the proper meaning. For instance using an end mill to trim off the trailing edge of the stator is milling. Using a 5-axis CNC machine to shape the convex and concave surfaces of the stator is also milling. Anyone with a Bridgeport in a back room can do one but the other takes a major investment in a complex machine along with big bucks for the computer software that is capable of generating the machine program. Not to mention paying a person who understands what's going on to run the machine. The company that uses the 5 axis approach is using the same technology that the US submarines use to make quiet screws (props) that propel them.

There are also other methods of making stators one of which is casting (a stator that would not need to have it's blades shaped). The best method of casting would probably be lost foam. There is yet another approach, which is fabracation where the parts are stamped out and then welded together. If you were to take all three types of stators and measure them on a Coordinate Measuring Machine the one that would hold the closest tolerances would be the one that was machined on a 5 axis-milling machine. The next would be the one cast using the lost foam method and the least accurate would be the fabricated stator.



Edward

 

[pwr2tow]

Very well done Edward.



Could someone answer Floor its question?



JSmith,

On my bd-power transmission the fluid coupleing is tight. You better have your foot on the brake when you put it in gear cause she is going to move. I can tow the weight in my signature up a very steep hill in first at 1,000 RPM's. At idle it will move the weight on flat ground, takeing off slowly and then up to approxiamatly 7 MPH.



Ron

 

[JSmith]

Is this it?

 

[rrausch]

Well, let me jump in here First of all... Great Questions!



The engine has to be turning at a greater RPM (in Drive) than the transmission for the stator to multiply torque. You are also asking about fluid coupling. ATS furnace brazes/welds and reinforces the Turbine & Impeller which makes fluid coupling tighter. But I'm not a trans expert. If you want a better explanation about ATS fluid coupling call them at 800-949-6002 Clint or Carl can answer these questions much better.



Stators:

I don't know any company anymore who is milling the stock stator by putting it in a vertical axis milling machine, or chucking it up in a lathe and lopping 1/4 inch or so off the front of the blades. As I understand it, at least one company did this several years ago, and the unintended side-effects produced such horrendous results that it gave a bad name to "milling" stators.



That said, the good folks at ATS do take a stock stator and go at it with a CNC machine. I was just at ATS 2 weeks ago and saw their CNC machine in action. Pretty awesome. They take the stock stator, in which the stator blades look kind of like a fat teardrop in cross section, and program the CNC machine to cut compound curves into both front and rear of each individual blade, to produce a curved spoon instead of a fat teardrop. It moves MUCH more fluid. Moving more fluid means faster accelleration! Stomp the pedal on any ATS truck, and you can feel (& hear!) the immediate difference.



I don't know of any other company with the ingenuity, resources and engineering talent to come up with this. When you add the stator design to the TripleLok design, and add in the other brilliant inovations Clint and Co. came up with you can see why I maintain ATS has done the most thorough job of engineering of any of the trans builders out there.