Ball drive fluid?

[69fury]

cross post from automotive but since we're just talking lubing a ball drive, here it is:
Some friends donated a Paxton supercharger for my vintage gasser Falcon build. The unit is a fairly rare VR4 unit that has much more load on the ball drive than typical Paxton SN units.

For those not familiar, the ball drive looks like the planetary from an auto trans,except with 1 inch ball bearings instead of gears. The pulley turns the cage (part 13,below), which run the planets around inside the shell races. The races are shimmed to force the balls into the center spindle, throwing it forward at much higher rpm. (part 16 ball drive assy.)

Based on a SN93 with a 1:4.44 step up ratio, the VR4 has upgraded housing/impeller, and the races are shimmed to twice the rotational set up tension as others, which increases the heat to a point that a hollow dipstick/pump/oil cooler is included (and barely keeps up with heat produced of this blower)

This "race only" blower is run by some on the street using a larger radiator/pump to cool it.

ATF or Paxton's atf is recommended with some running B&M Trick Shift atf. The B&M fluid supposedly gives the balls more grip on the inner shaft.

If there are any engineers around that know ball drives- how much does the device require "grip" vs "slip" of the fluid? Should a friction modifier be added to atf, or could too much cause more problems?

"they" say to stay away from synthetics in these, but "they" dont say why.

I have some friends that run turbo street cars (1000hp) using tractor hydro in the trans (with a quart of atf for color,lol) that claim tighter converter stall under boost...and that the trans loves it....

my point: is there a better fluid/additive that can handle the intense heat and transfer is off easily and still give the "slip" and "grip" needed for a ball drive? I'm trying to design a better cooling system with a bigger pump, radiator and 2-3 gallon reservoir (blower only holds 10 ounces of atf.)

thanx
-rick

 

[Shannow]

Wow, never saw one of these in that sort of power application.

Understood them for dentists drills, but not serious power.

You want something that's slippery against item 13, but allows proper herzian contact on 15 and 16.

Kestas should have some insight.

 

[69fury]

Kestas? member on the site?

 

[bruce381]

if they say ATF use that, ball bearing do not need any slip or friction modifier so perhaps a good ISO 46 hyarualic is all thats needed certianly an OLD style AFT will work like a DEX III the B+M ATF was/is the old Ford style AFT F no or not much friction modifier was used thats why they shifter harder
bruce

 

[Shannow]

bruce, these things are unusual for a ball race.

Think about them as sort of a sprag clutch, using the bearings to drive a torque load in a step up transmission arrangement.

ATF does clutches, so prolly correct.

 

[69fury]

i'm hearing to go with a synth type F (like Amsoil, maybe?) that the synth shouldn't hurt the seals (the rear seal is some kind of wicked graphite seal to handle the 65,000 output side.

can you guys school me on what friction modifiers do? I thought they aided in clutch grip, as the old trick for traditional chrylser trans was to use type f, because it had more (i thought) friction modifiers....

but now i see Amsoil synth F has NO friction modifiers and i'm confused.

-rick

 

[ac_tc]

This is an intresting one...
Not saying am an expert but i´d stay away from
ATF+4 and similar heavily friction modified fluids.
I´d would be tempted to run atf type a or f and
change frequently to compensate for shear down.
I might add a litle say 25% 75w-90 gl4 or gl4/gl5
gear oil to increase wear resistanse but id be wery
caution of slipping signs.
I´d would also be cautius of using syn since ive found that syn´s sometimes makes metal to metal drive (like syncros)
to slip, i belive that is because syn´s tends to cling firmer to metal.( this was a fact when racing the mopar a-833 tranny, syn oil and it shifted sooo slow. But it was almost 20 years ago i noticed that and things have surely changed since)