torque converter
04-06-2001, 06:40 PM
#1
A-CL nub
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torque converter
hey guys, i think this has come up before...but i have a question. what is a torque converter? and is it really supposed to give you that extra .5 to 1 second shave off of your quarter? thanks for the input. late
04-06-2001, 07:06 PM
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I'm sure someone will have a more astute response to your question, but this is my layman's answer:
The torque converter (t.c. from here on) is key to any automatic transmission. It allows the engine to be coupled to the driveline via a "viscous" coupling -- that is, there is a propellor disc on one end (the t.c.) and there is another propellor disc at the driveline end, like so: DL===I I===TC
The very thin, highly refined trans oil in the tranny is designed to allow the TC to propel the fan blades (on the propellor disc) of the driveline as soon as the brake is released. The connection is so tight that the oil spins so fast as the TC winds up (due to the engine speed increasing -- i.e. your accelerator) that the viscous flow of the oil pushes the blades of the drive-line fan-disc. THis is different from a manual tranny in that a "clutch" is used in a manual tranny, which is a DIRECT link between the engine and the drive-line. Hence, the power absorbed and wasted in an auto trans is preserved in a manual trans due to the direct connection. As you release the clutch, you disable the connection, and allow yourself to switch gears, and then re-apply the clutch.
Hope this is right, and I hope it helped -- I find the technology fascinating -- what is more fascinating is the new CVT trannies that are being introduced first in the Audi A4, 3.0. THere are NO gears -- just one that continuous varies the pseudo-gear-ratio .. CVT = Continuously varying transmission, and Audi's name for it is Multitronic.
------------------
2002 TL Type S
White Diamond Pearl
No Mods
The torque converter (t.c. from here on) is key to any automatic transmission. It allows the engine to be coupled to the driveline via a "viscous" coupling -- that is, there is a propellor disc on one end (the t.c.) and there is another propellor disc at the driveline end, like so: DL===I I===TC
The very thin, highly refined trans oil in the tranny is designed to allow the TC to propel the fan blades (on the propellor disc) of the driveline as soon as the brake is released. The connection is so tight that the oil spins so fast as the TC winds up (due to the engine speed increasing -- i.e. your accelerator) that the viscous flow of the oil pushes the blades of the drive-line fan-disc. THis is different from a manual tranny in that a "clutch" is used in a manual tranny, which is a DIRECT link between the engine and the drive-line. Hence, the power absorbed and wasted in an auto trans is preserved in a manual trans due to the direct connection. As you release the clutch, you disable the connection, and allow yourself to switch gears, and then re-apply the clutch.
Hope this is right, and I hope it helped -- I find the technology fascinating -- what is more fascinating is the new CVT trannies that are being introduced first in the Audi A4, 3.0. THere are NO gears -- just one that continuous varies the pseudo-gear-ratio .. CVT = Continuously varying transmission, and Audi's name for it is Multitronic.
------------------
2002 TL Type S
White Diamond Pearl
No Mods
04-06-2001, 07:52 PM
#3
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so basically the torque converter retrieves the power loss that the auto produces?? and therefore keeping as much power as a manual does??? if this is true please let me know, and if it's wrong, please correct me
04-06-2001, 08:28 PM
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If I'm understanding what you said correctly, then no.
The torque converter is the CAUSE of the loss of power in AUTO transmissions, and the CLUTCH is the reason why manuals have the full breadth of the engine's power. When you brake-torque a car on acceleration, you have your foot on the brake pedal (impeding forward motion) and you're INCREASING the engine's revolutions to about 1000/2000 rpms. While this DOES overheat the tranny, it also starts to spin that transmission oil like crazy, so when you finally release the brake and CONTINUE TO KEEP YOUR FOOT ON THE ACCELERATOR (and subsequently FLOOR IT), the oil has already been spinning at a high fluid velocity and it gives you a better acceleration response -- the torque converter doesn't have to begin to wind up from 500 rpms (engine baseline usually). This will give you a couple extra "ticks" (or .1 increments) on your 0 to 60 time. Hope this helped!
------------------
2002 TL Type S
White Diamond Pearl
No Mods
The torque converter is the CAUSE of the loss of power in AUTO transmissions, and the CLUTCH is the reason why manuals have the full breadth of the engine's power. When you brake-torque a car on acceleration, you have your foot on the brake pedal (impeding forward motion) and you're INCREASING the engine's revolutions to about 1000/2000 rpms. While this DOES overheat the tranny, it also starts to spin that transmission oil like crazy, so when you finally release the brake and CONTINUE TO KEEP YOUR FOOT ON THE ACCELERATOR (and subsequently FLOOR IT), the oil has already been spinning at a high fluid velocity and it gives you a better acceleration response -- the torque converter doesn't have to begin to wind up from 500 rpms (engine baseline usually). This will give you a couple extra "ticks" (or .1 increments) on your 0 to 60 time. Hope this helped!
------------------
2002 TL Type S
White Diamond Pearl
No Mods
04-06-2001, 09:07 PM
#5
Suzuka Master
There is a little more to this:
Our torque converter and transmission are computer controlled. The gears in the transmission are computer controlled *and* the torque converter is also computer controlled. Why does this matter?
Our cars have a "lockup" torque converter.
it works in 3 ways
1. just like you explained -- it allows for
"slippage" between the engine and transmission.
2. With partial slippage (it had a lockup clutch)
3. With no slippage -- just like a real manual transmission.
An easy example to watch when your driving our car vs. a stick is to watch how the tach needle floats up from (2000 - 2400) rpm while we drive at a constant speed cruising down the road. The converter is not locked up, it is allowing the engine to speed up a bit (taking up some slack) while the road speed only changes a tiny bit. If this was a manual, you would press down and with each rise of the tach needle, there would be a rise in the road speed. So, while cruising and at low speeds the converter is "wasting" energy and allowing slip to occur.
When full power and certain speeds are attained, the torque converter LOCKS UP -- it has a lockup clutch that ties the input and outputs together, just like the clutch in a "real" manual transmission. So, for a good part of an acceleration run, the engine is hooked up to the transmission rather solidly (any mods to the torque converter in this mode are not going to help -- its locked/stuck/fixed)
The torque converter also does some locking up when we go down hills. In older automatics, when you shifted down to lower gears, the engine braking was rather weak.
The Acura has "grade logic" to simulate engine braking on downhill slopes.
The BIG DEAL with the Level 10 stuff, is to get the "stall" speed of the converter from its current 2200-2400 (I'm off a bit) to a higher speed. This allows someone who wants to really jam off the line to get the engine up to a higher speed, like 3000 rpm where there is more power.
With most of the hopped up torque converters, they will have a chart of modifications for a given car:
A street racer may have its torque converter modified for a stall speed of 3000 rpm.
A highly modified street racer may have it raised to 3500 rpm.
A race version would have this speed set even higher.
Its kind of like thinking of slipping a clutch on a an Indy car. If you were in one of those 15,000 rpm suckers, and you tried to engage the clutch at only 1000 rpm, you would kill the engine.
Now if you raise the rpms to 3000 or 4000 is still wants to bog, but it might stumble off.
Finally, with a real good set of rpms, and good clutch let-off, the car gets going at a speed where the engine has some balls.
If our torque converter had a stall speed of 600 rpm, people would be stalling all over town. The engine just wouldn't have enough revs on it before it got loaded down (kinda like the Indy car).
So, that is the best I can do.
There are some links to level10 and a look in google with the keywords, torque converter operation, should turn up a few hits.
--- OUCH ----
------------------
Silver 2001 CL-S with NAVI
Our torque converter and transmission are computer controlled. The gears in the transmission are computer controlled *and* the torque converter is also computer controlled. Why does this matter?
Our cars have a "lockup" torque converter.
it works in 3 ways
1. just like you explained -- it allows for
"slippage" between the engine and transmission.
2. With partial slippage (it had a lockup clutch)
3. With no slippage -- just like a real manual transmission.
An easy example to watch when your driving our car vs. a stick is to watch how the tach needle floats up from (2000 - 2400) rpm while we drive at a constant speed cruising down the road. The converter is not locked up, it is allowing the engine to speed up a bit (taking up some slack) while the road speed only changes a tiny bit. If this was a manual, you would press down and with each rise of the tach needle, there would be a rise in the road speed. So, while cruising and at low speeds the converter is "wasting" energy and allowing slip to occur.
When full power and certain speeds are attained, the torque converter LOCKS UP -- it has a lockup clutch that ties the input and outputs together, just like the clutch in a "real" manual transmission. So, for a good part of an acceleration run, the engine is hooked up to the transmission rather solidly (any mods to the torque converter in this mode are not going to help -- its locked/stuck/fixed)
The torque converter also does some locking up when we go down hills. In older automatics, when you shifted down to lower gears, the engine braking was rather weak.
The Acura has "grade logic" to simulate engine braking on downhill slopes.
The BIG DEAL with the Level 10 stuff, is to get the "stall" speed of the converter from its current 2200-2400 (I'm off a bit) to a higher speed. This allows someone who wants to really jam off the line to get the engine up to a higher speed, like 3000 rpm where there is more power.
With most of the hopped up torque converters, they will have a chart of modifications for a given car:
A street racer may have its torque converter modified for a stall speed of 3000 rpm.
A highly modified street racer may have it raised to 3500 rpm.
A race version would have this speed set even higher.
Its kind of like thinking of slipping a clutch on a an Indy car. If you were in one of those 15,000 rpm suckers, and you tried to engage the clutch at only 1000 rpm, you would kill the engine.
Now if you raise the rpms to 3000 or 4000 is still wants to bog, but it might stumble off.
Finally, with a real good set of rpms, and good clutch let-off, the car gets going at a speed where the engine has some balls.
If our torque converter had a stall speed of 600 rpm, people would be stalling all over town. The engine just wouldn't have enough revs on it before it got loaded down (kinda like the Indy car).
So, that is the best I can do.
There are some links to level10 and a look in google with the keywords, torque converter operation, should turn up a few hits.
--- OUCH ----
------------------
Silver 2001 CL-S with NAVI
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04-07-2001, 04:50 PM
#7
A-CL nub
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thanks so much for the information. it helped out A LOT. i'm looking into buying a level 10 torque converter once i figure everything out and stuff. later
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