Torque converter

[2 Fast 4 U]

I have 3 torque converters in my garage two with a spot of green paint and one with a spot of yellow paint, does this have any meaning??

[RallyBob]

Originally Posted by 2 Fast 4 U I have 3 torque converters in my garage two with a spot of green paint and one with a spot of yellow paint, does this have any meaning??

I seem to recall that the green paint was more common...used in Manta/Ascona.

I *think* the yellow was used in the GT (and possibly others), because it has a slightly higher stall speed (about 200 rpm higher), for more 'sporty' driving.

Just going off 20+ year old memory though!

[2 Fast 4 U]

Thanks Bob, can I use the yellow one in the Ascona??

[RallyBob]

Sure, no problem!

[2 Fast 4 U]

Thank you!!

[2 Fast 4 U]

Originally Posted by RallyBob .......because it has a slightly higher stall speed (about 200 rpm higher), for more 'sporty' driving......

Bob what do you mean with the "higher stall speed"

[BQS4]

Originally Posted by 2 Fast 4 U Bob what do you mean with the "higher stall speed"

It means the shift points are raised, or rather it shifts at a higher speed for better accelleration. Kinda like having a free "shift kit", or did ya'll have them over there?

[2 Fast 4 U]

Originally Posted by BQS4 It means the shift points are raised, or rather it shifts at a higher speed for better accelleration. Kinda like having a free "shift kit", or did ya'll have them over there?

stupid me but what is a "shift kit"

[BQS4]

Originally Posted by 2 Fast 4 U stupid me but what is a "shift kit"

A company, here in the US, called B&M makes them for most of the older vacuum shifted trans. to raise the shift points, being able to hold a gear longer for higher revs, but, this takes it's toll on a trans over time.
Welcome to B&M Racing & Performance Products!

[2 Fast 4 U]

I found this at TRANSMISSION EXCHANGE CO

Torque Converter Stall Speed

To test the stall on your current torque converter: With the engine running and the brake pedal held firmly with your left foot put the selector in drive and depress the accelerator fully to the floor with your right foot for two to three seconds. Your stall speed will be the maximum RPM shown on the tach.

so if I understand correctly the stall speed is actualy the maximum RPM the torque converter can make/let thru

[BQS4]

yes, the higher an auto trans goes through the rpm before it shifts to the next higher gear means you accellerate faster, like holding a manual trans in gear till the rpms tell you you're not getting any more power out of that gear, then you upshift.

[wrench459]

A higher stall convertor will allow the engine to rev into a higher spot(before locking) of the power curve. If you look at the difference in the two attachments you'll see want I mean.Attachment 21953Attachment 21954
The first marker is the power at 2000 rpms(26.60). The second marker is at 2500 rpms(33.68).
Now if you want to get crazy let's put a 4000 rpm stall into the old girl!

[2 Fast 4 U]

Originally Posted by wrench459 .......Now if you want to get crazy let's put a 4000 rpm stall into the old girl!....

I'll think I'll pas on that one

[2 Fast 4 U]

How can I clean/flush the torque converter on the inside?? I want to do this before I put it in the car

[guyopel]

Most Trans. shops have a Machine to clean the converters and then cut them apart to rebuild them.
There is not much you can do at home because any cleaner you try to use it would be hard to get it all flushed out ( Trash you broke loose would still be in the converter ).
If you are not sure about your converter I would have a Trans. Shop rebuild the converter ( This would get unit cleaned and balanced and new thrust washers and sprag clutch inspected ) HTH

[2 Fast 4 U]

Thank you guyopel

[2 Fast 4 U]

I'm still puzzeled about the stall speed, I tried it out today, left foot on the brake, shift into "D" and put the accelerator to the floor, result almost 2000 RPM.
When I'm pulling up with the accelerator to the floor [just before the kick-down point] the trans shifts at ± 4000-4500 RPM, from 1-2 and 2-D, and in the kick-down point, the trans shifts at ± 5000-5500 RPM, from 1-2 and from 2-D it doesn't reach the shifting point so I let the accelerator come up a little so it can shift
So what's with the 2000 RPM, and the 4000-5500 RPM shifting points??

[kwilford]

Originally Posted by 2 Fast 4 U Bob what do you mean with the "higher stall speed"

Originally Posted by BQS4 yes, the higher an auto trans goes through the rpm before it shifts to the next higher gear means you accelerate faster, like holding a manual trans in gear till the rpms tell you you're not getting any more power out of that gear, then you upshift.

Not AFAIK, Gene. As described below, the "stall" speed of a torque converter is the rpm below which the converter will allow slip (i.e. the engine will rev to that rpm BEFORE power is transmitted to the transmission), above which the converter "grabs" (transmits power). The "shift points", while related to torque converter stall, are inherently not, in that internal transmission valving determines at what rpm/load the transmission shifts (either up or down), not specific torque converter stall speed.
A higher "stall" converter allows the engine to rev to a higher rpm before transmitting that power, which is desirable for drag racing or engine applications where the engine develops little power at lower rpm (eg a cam design that provides higher high-rpm power but poor low end power)

Originally Posted by wrench459 A higher stall converter will allow the engine to rev into a higher spot(before locking) of the power curve. If you look at the difference in the two attachments you'll see want I mean.Attachment 21953Attachment 21954 The first marker is the power at 2000 rpms(26.60). The second marker is at 2500 rpms(33.68). Now if you want to get crazy let's put a 4000 rpm stall into the old girl!

Originally Posted by 2 Fast 4 U I'm still puzzled about the stall speed, I tried it out today, left foot on the brake, shift into "D" and put the accelerator to the floor, result almost 2000 RPM. When I'm pulling up with the accelerator to the floor [just before the kick-down point] the trans shifts at ± 4000-4500 RPM, from 1-2 and 2-D, and in the kick-down point, the trans shifts at ± 5000-5500 RPM, from 1-2 and from 2-D it doesn't reach the shifting point so I let the accelerator come up a little so it can shift So what's with the 2000 RPM, and the 4000-5500 RPM shifting points??

Converter stall is as I described above, which would indicate that your's has a 2000 rpm stall. Shift points are determined by transmission valving, and vary according to load, rpm and throttle position (ie, the "kick down cable"). If your transmission won't upshift from 2nd to 3rd gear at full throttle, then the kick down needs to re adjusted or your transmission has a valving problem.

HTH

[Aardvaark]

When I switched to 205-60/13 tires from 175-80/13 tires I guess
my Manta's effective stall speed got raised. It sure feels peppier.

[wrench459]

Originally Posted by Aardvaark When I switched to 205-60/13 tires from 175-80/13 tires I guess my Manta's effective stall speed got raised. It sure feels peppier.

Now thats funny.. It's not like you changed the overall gear ratio.

In order to get a good reading of the TQ stall speed.
Flash the fluid coupler..dont power brake it.
That is with the trans in drive and at idle speed nail the throttle..when the car starts to move thats the true stall speed of the convertor. Next problem is the stock tack is way off so you really cant use that info . You'll need a better input.
Ok now let's blow some minds.
You can take the same convertor from a low torque engine an install it into a higher torque engine and the stall speed will change!

[2 Fast 4 U]

Originally Posted by wrench459 ......Ok now let's blow some minds......

Well you blew mine

It's getting complexer with every posting

[american opel]

i converter has nothing to do with shift points.it is a {torque converter}which means it multiplies torque.if you put a 500 rpm above stock converter in a small low hp engine it might stall at 1700 rpm.if you take that same converter and put it in a big block chevy it might stall at 3200 rpm.i have had some conv.made for some cars.they ask you what kind of cam,compression,engine,car weight and what stall you want.they take all of that info.and change the conv.to your specs.i had one made for an amc jeep motor.they took 12"converter and cut off the front and welded on a 10"front to get me a 3500 stall.having a higher stall helps your car go faster off the start because your car makes more hp,torque at 2800rpm than 1700.most of the time 500 more rpm than stock is enough,but if you install a huge cam the car wont idle at say 650rpm so you need to raise it to 750.if you have a stock converter your car wants to lunge forward because it is starting to lock up.the higher stall will let the car idle and not move till you rev it up to 1200 then full lock up at 2500.

[american opel]

here are some pics of my car.

[RallyBob]

Originally Posted by 2 Fast 4 U Well you blew mine It's getting complexer with every posting

Like these guys have said, the converter has nothing to do with shift points. The stall speed is simply the point at which the torque converter no longer 'slips', and the maximum hydraulic coupling is attained.

A stock Opel converter is 9", it generally stalls at 2000-2200 rpms behind a 4-cylinder Opel engine. I usually have them modified for a 3000 rpm stall speed for street cars. This way, when using a 'big' camshaft that idles higher than normal, the car does not 'creep' forward when in gear. It also allows for better acceleration as a bigger camshaft has it's power and torque at a higher rpm, so it lets the engine rev past this weak rpm area.

[2 Fast 4 U]

I got this of the www

How a Torque Converter Works

The torque converter is designed to act as a fluid coupler that can engage and disengage with the increase and decrease of engine rpm. When the vehicle is not in motion while the engine is running the torque converter is in action. The torque converter converts fluid pressure to lock the converter output shaft. Once the shaft has locked the transmission receives engine power. At minimum engine rpm fluid pressure is low and the torque converter allows the engine to "freewheel" from the transmission.

When the converter receives the power from the engine it transfers power to the transmission. The torque converter also has the ability to multiply torque when the engine is under power by multiplying fluid pressure through a component called a stator.

The stator allows the smooth transition from standing still to motion of the vehicle. The torque converter is filled with automatic transmission fluid pumped in from the fluid pump of the transmission. There is a measured amount of heat generated by the torque converter. This is why a transmission fluid cooler is necessary, usually installed inside the engine radiator. Most torque converters are equipped with a clutch that has the ability to lock up as the vehicles reaches cruising speeds. The clutch is activated by a fluid control solenoid inside the transmission that is activated by the ECM . Transmission fluid passes through the torque converter and needs to be as clean as possible to ensure proper operation and limit malfunctions. Always observe manufacturers recommended transmission service intervals.

The torque converter can cause the engine to stall. The fluid coupler known as the torque converter is constructed with clutch shoes that lock up to connect the engine at cruising speeds. If the torque converter malfunctions it can cause the clutch shoes not to release. This will cause the engine to stall at idle because the torque converter will not release, forcing the engine to stall. This condition will usually start to occur after long a drive on the freeway and get worse from there. If your car shutters as it is coming to a stop and then stalls you could have this problem. If you are coming to a stop and you think this is your problem try putting the car into neutral gear and see if it still stalls. If the engine does not stall when in neutral the torque converter has failed and needs replacing. Unfortunately the only way to replace the torque converter is to remove the transmission. (Always flush the transmission fluid and replace the filter anytime major work is performed)

Note:
cars with automatic transmissions are equipped with a torque converter that when it fails will cause the engine to stall, but only when you put the transmission into forward or reverse gear.)

I got a lot more stuff of the www, I'll try, when I have more time [in the near future], to put it all together and see if I can post it here, if anyone is interested in it