Educate me Torque converter

[jekquistk5]

Ok, So I will be tearing down into my tranny to replace seals, because its leaking arround the bellhousing, and I figure Since I have to pull the tranny while its out why not replace the torque converter with a better one. So for offroading whats the best? I was looking at jegs with there street /stip converters that have a 2800-3000, and 3200-3600 rpm stall. Whats the best, and explain to me stall? thanks guys i'm new to auto trannies.

 

[Thunder]

You match the stall speed of the convertor to your cams power curve. So if you have a cam that has a power band say between 2500 - 6000 RPM you would want at least a 2800 stall convertor.
Stock cam = stock convertor.
For off road you should use the lowest stall convertor you can. The lower RPM your convertor hydraulicly locks the less heat it will generate.

 

[big83chevy4x4]

FYI, stock stall speed on a fullsize is about 1400. ive always put a 1600 stall converter in my trucks (s10s with 4.3s). the cars i put a 2000 stall converter in (corvettes, 9C1s)

i really like the 1600 stall for sand and mud, its better on the street and on the trail (IMHO) than the lower 1400 stall.

 

[dirtwarrior17]

You match the stall speed of the convertor to your cams power curve. So if you have a cam that has a power band say between 2500 - 6000 RPM you would want at least a 2800 stall convertor.
Stock cam = stock convertor.
For off road you should use the lowest stall convertor you can. The lower RPM your convertor hydraulicly locks the less heat it will generate.

not necessarily.... If you want to win mud comps then you want a higher stall converter. Like thunder said, stall is when your t/c hydralically locks the engine and tranny together so the flywheel and input shaft are spinning at the same speed. I chose a 2400 stall converter because of my cam and also because i wanted it to launch like a mother farker. when your towing or rock crawling the lower the stall the better but when you need to get up some speed from a stop a higher stall speed is ideal.

 

[big83chevy4x4]

stall is when your t/c hydralically locks the engine and tranny together so the flywheel and input shaft are spinning at the same speed.

stall speed is the fastest the motor can spin the converter with the input NOT turning. stall speed also is not exact, it is effected by the HP of the engine.

 

[ntsqd]

stall speed is the fastest the motor can spin the converter with the input NOT turning. stall speed also is not exact, it is effected by the HP of the engine.

What he said.

 

[dirtwarrior17]

stall speed is the fastest the motor can spin the converter with the input NOT turning. stall speed also is not exact, it is effected by the HP of the engine.

uh thats the same thing........

you misunderstood what i said.

 

[k20]

and, atleast B&M's converters, the advertised stall speed is based off 230ft/lbs @ 2500rpm. More tq at that rpm, will deliver more stall.

 

[Mad-Dog]

For general off-roading or rock crawling you don't want a stall converter, just learn to live with throwing her in neutral at a light.
If ya slip a pretty healthy bumpstick in the mouse then a TCI Sizzler will supply a 1600-1800rpm stall and is as big as i would go on the street, I'm sure you don't want to rev the engine to 3,000 rpm while trying to back into a parking spot at Wally-World...........SLAM !@#$%^&**, right into the car behind you.
I run a Comp XE274H in my K10 and it idles with a controlled rumble around 1200rpm which makes it really frikkin hard to hold still in gear when stopped so i just throw her in neutral and watch the people in the car next to me roll their windows up and stare in amazement..........

 

[jekquistk5]

Well my truck doesn't see much street, so thats not a problem.!!, and I'm getting parts together to put a 465 in anyways! Just not right away, id say in about 6 months or so.

 

[Ryan B.]

I had a 1600-1800 stall converter in my k5. It was cool for sand and mud racing. but thats about it.
Once i started getting into more trail driving and rock crawling, i realized the tranny was just building a lot of heat when i was trying to crawl along. Wished i went with a stock converter then. So it really depends on what your going to be doing.
My Camaro has a 3,000 stall converter with a big cam for 3K-7K rpms. Its not real streetable, and i have to be above 3K on the freeway, otherwise its slipping.

 

[jekquistk5]

Ok, I'm more of a trail type of guy, looks like the stock one is staying in.

 

[Mad-Dog]

ten-4.............slide a healthy solid lifter grind in there and put the fuel to her..........

 

[trailblazr81]

My K20 has a 450HP 383 in it. I use a TCI sizzler which is one up from a stock converter. I like it and I wouldnt go higher. I had a 383 in a K20 about 5-6 years ago with a 2000 RPM stall. I took it out after a couple weeks. You have to rev motor every time you want to get crawling. Wasnt fun when backing up or in parking lots. Imaginew having to hit 2000RPM to pull forward a foot. I can still "feel" the Sizzler but barely. I would probably go the same route next time.

 

[ntsqd]

uh thats the same thing........

you misunderstood what i said.

This is what you said:

Like thunder said, stall is when your t/c hydralically locks the engine and tranny together so the flywheel and input shaft are spinning at the same speed.

Which is exactly opposite of what happens:

stall speed is the fastest the motor can spin the converter with the input NOT turning. stall speed also is not exact, it is effected by the HP of the engine.

The trans and converter act like a dyno in that the engine can not spin faster regardless of throttle setting. Stall speed depends on the torque that a engine makes. If a high torque engine is used with some nominal RPM stall converter it will actually stall at a slightly higher RPM than if that same converter is bolted behind an engine that makes less torque.
A higher stall converter allows the engine to rev higher than a lower stall converter, but each limits the engine speed to a specific RPM while the vehicle is NOT moving. It is very hard if not impossible for a non lock-up converter to stall while the vehicle is in motion (i.e. input and output shafts turning EXACTLY the same speed). This is why lock-up converters exist and why you loose 100-300 RPM thru a non lock-up converter at highway speeds.

 

[dirtwarrior17]

So your saying that in order for a truck to move the input shaft never moves and the torque converter just spins?

Go back and read my post then read what you just posted.... It is exactly the same.

Still don't understand how you don't get this.

In order for a vehicle to move with a stall converter the input shaft HAS to turn... Stall is the rpm at which it starts to turn.

I'm not about to start this with you so go back and read what a said again without twisting my words.

 

[big83chevy4x4]

Stall is the rpm at which it starts to turn.

no its not. other words the stall on a STOCK converter is 600.

i know what you said and understand it completely, but its wrong and is not the same as i said.

 

[dirtwarrior17]

stall speed is the fastest the motor can spin the converter with the input NOT turning. stall speed also is not exact, it is effected by the HP of the engine.

sounds the same to me......

 

[big83chevy4x4]

think 2 box fans side by side (to replicate the torque converter). the first one is on (engine side) the second one is off (tranny side). now, stop the second one. the speed of the first one is the stall speed.

what i got from what you said was both were on and the speed together was the stall speed, or (you changed it in your 2nd to last post) as you are turning the first one on, when the second one starts moving is the stall speed.

 

[dirtwarrior17]

I understand how a t/c works.

I was saying when the two impellers are spinning at the same speed then you take the rpm of the motor and thats your stall speed. Never said combine em.

Can anybody clarify this?

your probably right but if i listen to everybody on here i would have been electrocuted, burnt up a tcase, fuel pump, etc.