high performance transmission gurus

[RatPoweredTruck]

So, I've read about remanufactured transmissions. I've read about high performance parts upgrades and such. It's all great reading material with lots of good stuff. I love the web... Well, kind of. The thing is that I would like to know about the oil pressures especially in high horsepower builds. I've done searches but I am at a loss. For some reason I keep thinking that all the hyped up, exotic metals parts just isn't enough to hold it all together when bolted behind a torque beast belching out 1000hp or higher. I have to wonder. What about the pump and the pressure it puts out?? I think a stock piece can only mustard 290psi-300psi max. Is this really enough to clamp down the clutches to keep them from turning to dust when there is boatloads of torque being applied that can snap gears, tear drivelines or twist u-joints to bits?
I have yet to find such information. Someone pleez shine some light into this obscure aspect of slushbox rehashing. I keep thinking oil pressure must also be increased to make everything tight otherwise slippage will destroy all the fancy stuff that costs as much as gold. Trying to add 2+2 but keep coming short.

[truckdude239]

they sell upgradeed pump vanes and stuff but remenber 2 much presssure makes for very hard shifts which can break hard parts

[PGSigns]

The pump pressure is limited by the case in a lot of applications. On a powerglide stock case 240 pounds of pressure on the trans brake will blow the adjuster out the side of the case. Have done that. What is important is adding more clutches. If you look at the racing drums you will see they carry more plates and steels. They also use materials like kevlar in the bands.
Jimmy

[Bigdav160]

Torque holding of the clutches will be determined by the clutch material, number and radius of the facings. Metal parts are upgraded

[clinebarger]

Originally Posted by RatPoweredTruck

So, I've read about remanufactured transmissions. I've read about high performance parts upgrades and such. It's all great reading material with lots of good stuff. I love the web... Well, kind of. The thing is that I would like to know about the oil pressures especially in high horsepower builds. I've done searches but I am at a loss. For some reason I keep thinking that all the hyped up, exotic metals parts just isn't enough to hold it all together when bolted behind a torque beast belching out 1000hp or higher. I have to wonder. What about the pump and the pressure it puts out?? I think a stock piece can only mustard 290psi-300psi max. Is this really enough to clamp down the clutches to keep them from turning to dust when there is boatloads of torque being applied that can snap gears, tear drivelines or twist u-joints to bits?
I have yet to find such information. Someone pleez shine some light into this obscure aspect of slushbox rehashing. I keep thinking oil pressure must also be increased to make everything tight otherwise slippage will destroy all the fancy stuff that costs as much as gold. Trying to add 2+2 but keep coming short.

You have to take in to account how much Force 300 psi can put on a clutch pack.

Lets say the Apply piston/servo is 5" in diameter.

Diameter = 5"
Radius is 1/2 of diameter = 2.5"
Radius = 2.5" x 2.5" = 6.25"

Pie x Piston Radius= 3.14 x 6.25" = 19.625" of Piston Apply Area.

Pressure x Piston Area= 300 X 19.625 = 5887.5 Pounds of Force.

Does over 5,000 pounds of force seem adequate?

[RatPoweredTruck]

Great info!! All of it. Just what I was looking to learn. It makes more sense now to know some of the capabilities/limitations of the components in the different applications. I just couldn't imagine how the transmission builders could build a unit rated at over 1500hp, for instance. PSI is the key to holding clutches under that much power. Very nice. Thank you.