Jason_GTA

I would have to say that they have something to do with "coverting torque" but that is where my knowledge ends. I would like to know waht they do, and how much they are and where are they locateed ont eh car. And how hard of a job is it to replace one or put one one, what ever the hell you do with them. Thankyou
Jason

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1988 Pontiac GTA
Loaded
350 700R4

Mark_ZZ3

Your question would be best answered on the

Transmission messageboard, not the TPI one.

Only dumb TPI tweakers in here ... :-P

Bill91Z

moving to tranny board

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-Bill
-=ICON Motorsports=-
Boston Chapter
91Z28, (in progress) 3.8L, TE63-1 turbo, MSD50lb injectors, Hemco upper, ported TTA heads, 62MM TB, Red's XP fuel pump, 3.73s, vigilante (stall to be determined)

TomP

They're between the engine and trans. They take the place of a clutch on a manual transmission.

Think of two box-fans, the ones you'd use in your house to cool yourself down. Face them at each other, and turn only the first one on. The wind from the first will start the other one spinning. Now, take your hand, and stop the non-powered fan.

This setup duplicates a torque convertor: The fan that's powered by the electricity is your engine. The non-powered fan is your transmission. The air between the two fans represents the transmission fluid inside.

The idea of stopping one fan with your hand is important; this is what happens when you come to a stop. Think of your hand as the car's brakes. (A manual-tranny car would have to push the clutch pedal in to disengage the clutch.) This also has to do with stall speed- one of the reasons people upgrade their torque convertor.

I'll leave the "upgrade" and "torque conversion" part to someone else... I'm not that good with explaining it. I barely understand it myself!

To replace your stock unit, you'd have to remove your transmission, pop the old one off, put the new one on, and put the trans back up.


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards

ws6transam

I just changed my TC by myself and it took about six leisurely hours, spaced over the course of four evenings. Some tools such as a 3-foot socket extension, 9/16 swivel socket, four jackstands, a floor jack, and a transmission jack from Harborfreight are also necessary. I didn't even skin any knuckles!


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Daniel Burk
http://www.isthq.com/~dan/fcar.html
'84 Trans Am WS6/L69
KB SFC, Moser axles, Torsen Diff. PST suspension, Braided stainless brake lines,
5-point racing harness, Koni struts, 11-inch rear disks,Spohn Adj. torque arm,
Ported 305 heads w/1.94"intake valves, Comp Cams XE262H, Griffen alum. radiator,
Speed-sensitive steering conversion, underdrive pulleys, Crane Hi-6 & more. 1.05g skidpad verified.
New best E/T! 14.400 at 98.6 MPH in 88 degree air at Stanton, Michigan.

ws6transam

Okay here we go: The difference between a clutch and a torque converter. Never before published, 'cause no one can explain it without math and physics.

First off, let's discuss the clutch. When the clutch is locked up, there is a 1:1 transfer of energy to the transmission. The drive wheels are essentially locked to the flywheel such that the only loss is from friction. The torque transfer is rated as Torque output divided by torque input. The best that a clutch can accomplish is a transfer factor of 1.

There are two kinds of friction coefficients: Static and dynamic. every type of material, be it concrete, aluminum, steel, diamond, rubber, or clutch, has two different coefficients of friction. Usually the static coefficient is greater than the dynamic. This is why a tire slows you down faster during braking if it isn't locked up. Once you begin to slide, the dynamic coefficient of friction applies. The same thing occurs in a clutch. Once you begin to slip a clutch, dynamic coefficient of friction applies, and there is less friction. Now, it doesn't matter how fast you slip the clutch: Friction is not determined by the relative speeds of the materials(otherwise known as slip). Friction is dependent only on the load you apply to the materials. Therefore, the harder you press the parts together, the more friction will exist. Now, a more powerful engine will allow you to increase slip at a given amount of friction, but it won't allow you to increase friction. That is entirely a function of the spring load inside the clutch! Because of this principle, a clutch will never output more torque than what is input. The torque multiplier will never exceed 1.

A torque converter does not use a clutch (except for locking at cruise conditions, which I will NOT discuss at this time). Instead, it uses a series of vanes and hydraulic fluid to transfer energy. One set of vanes are attached to the outer housing of the torque converter, which is itself attached to the flexplate of the engine. As the engine spins, hydraulic fluid is picked up by the inner portion of the vanes. Centrifugal forces spin this fluid outwards where it picks up velocity. When it reaches the end of the vane, it is flung forwards at high velocity, right into another set of vanes. These vanes are attached to the input shaft of the transmission. I think this assembly is called the stator. Think of them as a catcher's mit: They "catch" this high velocity fluid, and absorb the energy. Most of this energy is transformed into a torque onto the input shaft. Some of the energy is turned into heat, however.

In the case of a torque converter, the amount of energy received by the stator is not a function of friction, but by the velocity (and momentum) of the fluid being thrown at it. Thus, output torque is a function of the velocity of the fluid being flung off the input vanes. Since the velocity of the fluid is related to the RPM at which the vanes rotate, output torque becomes a function of slip! In cases where the stator and input vanes turn at the same speed, slip equals zero, and torque multiplier equals 1. As slip increases, however, more energy is imparted into the stator, resulting in an increase of torque. Thus, the torque multiplier can increase above a factor of one. What this means is that if you input 300 ft.lbs at 3000 RPM, and the stator is turning 2000 RPM, your output at 2000 RPM will exceed 300 ft.lbs.

This is obviously a simplified discussion of operation. Whenever you transfer energy via fluid (be it air, or ATF), you can never transfer 100% of the energy. Therefore, a torque converter will "lose" energy during the process. In the case of a drag race, this is most evident at the top end of the track. The torque converter will let you launch hard due to torque multiplication, but as you approach zero slip, the advantage of torque multiplication fades to the advantage of having a 1:1 transfer of energy in a non-slipping clutch. This is why a clutch is an advantage for high MPH on the track. It's also why Precision Industries can charge so much for their converters: Their lockup-style converters are strong enough that you can actually lock them up under full throttle, making your Vigilante converter act like a clutch.

fbodyking

Jason, don't feel bad I don't know either.

wyclefsirocz

i know what it is jus don't know how it works

9.0L Firebird

Some good primers on torque converters in non-tech english. Don't worry about your knowledge base, asking questions is the first step. In a nutshell, a torque converter allows a car's drivetrain to "freewheel" at idle and engage the driveline when you step on the gas. It is located between your transmission and your engine (further back on your car than the oil pan when looking from underneath)

The first link is an excellent overview

http://auto.howstuffworks.com/torque-converter.htm

http://www.protorque.com/protorque_new/techi/ti_al.htm