[454cutlass86]

Hey can anyone explain to me about stall converters, I know it depend on the cam, my cam calls for at least 2500. what would I benefit if used a 2500 compared to a 2800 or maybe higher, How do I figure out what is my perfect stall, thanks

[richard stewart 3rd]

Hi,
A high stall is like slipping the clutch, if you hold the break & give it gas the converter will slip, allowing your engine to start off in it's power band,
as for a normal start just pushing the gas peddle will move the car along, it just wont fully engage until you hit stall.
If you use a higher then stock converter, you need to use large coolers, the higher the stall, the larger the cooler.
Rich

[454cutlass86]

this is the cam im plan on running shoudl i go with the 2500 stall that it says


http://store.summitracing.com/partde...8&autoview=sku

[techinspector1]

Talk with the tech guy at your favorite converter manufacturer. Be prepared with all the info about the motor, trans, rear gear, tire size, weight of the car, intended usage, etc. The decision about what converter to use in any given set of circumstances is too important to be left to chance. That's the bottom line.

[DaSouthWon]

Is a difference of 300 RPM between two converters going to make much of a difference. For instance, if the cam he uses is rated at 2500 rpm, is it going to be ok if he uses a 2800 rpm converter? 454cutloose and I discussed this a few days ago through PM, perhaps someone can give a better explanation than I did.

[techinspector1]

"For instance, if the cam he uses is rated at 2500 rpm, is it going to be ok if he uses a 2800 rpm converter?"

Would I do it? Yep.

[454cutlass86]

i think id rather ru na smaller stall as possible liek the 2500 cause there cheaper , i was suut wonder what the differnce is because i see alot more people running higher converters

[DaSouthWon]

Driving wise, running to low of a stall is going to cause your motor to bog down at low rpms, and be sluggish at low speeds.

[runn141]

every 2800 stall converter i used didnt come in until 3200 rpm. i only use a 1900-2200 stall now,if not stock. but the camshaft i ran was 230 duration at .050, no more than that.

[cobalt327]

T/C stall ratings are necessarily a estimation.

A heavy vehicle will cause a T/C to flash higher, as will a high torque engine. Opposite for light vehicles or low torque set-ups. Weight and torque are just two things, other things enter into the picture.

There are just too many variables for the manufacturers to pin it down any closer than they do, IMHO.

[k.c.]

A guy I know has a big block with a cam that is 224/236 at .050 and less than 450 lift. He has a TH400 with a stock TH350 converter. He says this raised his stall, not much, but just enough. Now that seems to me to be a mid range cam, but with 3.50:1 gears he has no prob gettin outa the gate.
How does that converter raise his stall speed and about how much?

[RustoRod]

What do you want the vehicle to do ? If you are drag racing a converter that stalls at peak torque is the way to go. Also skimping on a torque conveter due to price often leads to dissapointment.

The best thing is to talk to a reputable torque converter company. What transmission are you using ?

[runn141]

Originally Posted by k.c.

A guy I know has a big block with a cam that is 224/236 at .050 and less than 450 lift. He has a TH400 with a stock TH350 converter. He says this raised his stall, not much, but just enough. Now that seems to me to be a mid range cam, but with 3.50:1 gears he has no prob gettin outa the gate.
How does that converter raise his stall speed and about how much?

a turbo 400 converter is 13 inch diameter, which makes it about a 1200 stall speed. a 350 turbo is 12 inch and around 1600 stall. me personally i dont like any stall converter if i can get a way with it. i like using a 400 converter in my 350 turbo's.

[454cutlass86]

Originally Posted by RustoRod

What do you want the vehicle to do ? If you are drag racing a converter that stalls at peak torque is the way to go. Also skimping on a torque conveter due to price often leads to dissapointment.

The best thing is to talk to a reputable torque converter company. What transmission are you using ?

when its a street engine , and the cam calls for at least 2500 i just didnt know what would be best i have 3.42s in the rear

[PatM]

I think I'd use the converter the manufacturer recommends. If that's a stall value of 2500 at the minimum, and you're not racing every weekend, I'd use 2500.

While there are no specific standards, converter stall speeds are rated by manufacturers at some relative torque value. Say, for instance, the converter will stall at 2500 RPM IF the engine is producing precisely 300 ft-lbs at 2500 RPM. If you increase the engines torque at 2500 RPM, the stall speed will move to the right on your tachometer. On the other hand, if the converter is rated to stall at 2500 RPM (manufacturer establishing the standard at 300 ft-lbs) and your engine produces less than 300 ft-lbs at 2500 RPM, then the converter will stall a little to the left on the tachometer.

Try running a computer dyno simulation of your engine setup, see what the torque curve looks like, ask your converter supplier how much torque the candidate converter is rated at, and note if the stall will move up or down. If it moves down, buy a higher stall converter. Minimum means minimum. If it moves up, go with it. The higher stall will only be really obvious when you're producing lots of torque. In other words, when your foot is buried on the accelerator. And, that is when you most want the stall to rise.

Unless the vehicle is very light, you might want to reconsider the differential ratio.

Pat