Why do I want a higher stall TC?

[vtwinsport]

Hey all,
Why would I want a higher stall torque converter? And, what does that mean "stall".
I know this may obvious to others but I've never had it explained. Considering an upgrade as my tech shop advises a higher stall TC with new cam and heads coming.
Thanks in advance

[Keith Seymore]

"Stall" is when you smash your foot on the gas, and smash your foot on the brake and note where your engine rpm ends up (like 2500, or 3000 rpm, or whatever).

(...assuming the brakes hold!)

You want a higher stall mostly for racing or brisk street driving, since it will get your engine rpms up into the power band sooner. This would be important if you are going to a cam or intake/carb combination that doesn't like low rpms.


K

[spinem]

Originally Posted by Keith Seymore

"Stall" is when you smash your foot on the gas, and smash your foot on the brake and note where your engine rpm ends up (like 2500, or 3000 rpm, or whatever).

(...assuming the brakes hold!)

You want a higher stall mostly for racing or brisk street driving, since it will get your engine rpms up into the power band sooner. This would be important if you are going to a cam or intake/carb combination that doesn't like low rpms.


K

smash what?....no no no, stall referrs to what RPM the car will begin to move at... if its a 500 rpm stall, the car will wanna move even with ur foot on the brake, (given ur idle is above 500rpm) if u have a 2000 rpm stall and let ur foot off the brakes the car will stand still (given ur car is idleing below 2000 rpm)

you will need a higher stall if ur upgrading to a large cam (wont idle)
another bonus is to get the car in the power range immedently (I have a 2000 stall)....

the freeway thing, yes, if u have a 4speed tranny with 4th going 70mph at 1500 rpm and you have a 2000rpm stall, yes, your torque converted will slip, thus causing premature wear, excessive heat and overall bad news.

i think what the person i quoted was trying to say is some people buy torque converters with a stall at their power range.... example:
car makes 300hp at 3,400rpm and 120 at 2000rpm, its a race car.... when u jump off the line, u wanna be making 300hp immediately, no lagging.

keep in mind a torque converter is not like a clutch, it works using hydro pressure, not physical contact of disks.

you should look into trans brakes also, some good stuff there.

[68Timber]

Originally Posted by spinem

smash what?....no no no, stall referrs to what RPM the car will begin to move at... if its a 500 rpm stall, the car will wanna move even with ur foot on the brake, (given ur idle is above 500rpm) if u have a 2000 rpm stall and let ur foot off the brakes the car will stand still (given ur car is idleing below 2000 rpm)

you will need a higher stall if ur upgrading to a large cam (wont idle)
another bonus is to get the car in the power range immedently (I have a 2000 stall)....

the freeway thing, yes, if u have a 4speed tranny with 4th going 70mph at 1500 rpm and you have a 2000rpm stall, yes, your torque converted will slip, thus causing premature wear, excessive heat and overall bad news.

i think what the person i quoted was trying to say is some people buy torque converters with a stall at their power range.... example:
car makes 300hp at 3,400rpm and 120 at 2000rpm, its a race car.... when u jump off the line, u wanna be making 300hp immediately, no lagging.

keep in mind a torque converter is not like a clutch, it works using hydro pressure, not physical contact of disks.

you should look into trans brakes also, some good stuff there.

Keith described flash perfectly...

[joe231]

yeah what Keith said.
If you power is up high and you have a factory stall it will be gut-less off the line.

[dv8customs]

Detailed explanation from TCI's website

http://www.tciauto.com/Products/Tech..._explained.asp

[3r!c84]

what about just if your going 60 at like 2200 rpm will the converter lock up or will it be slipping becuse its a high stall(i never realy got this??)

[68 TT]

Originally Posted by 3r!c84

what about just if your going 60 at like 2200 rpm will the converter lock up or will it be slipping becuse its a high stall(i never realy got this??)

If you have a lock up type torque converter it will, if not the trans will be slipping a little at that speed. It will still move just not as efficiently as a lower stall would at the same RPM.

This is where a lock up type converter really works the best. You can have the high stall to get you moving quicker but have the cruise efficiency when it locks up.

Drag racers even use them with multiple lock up clutches to gain top end MPH and eliminate slip. I had a five clutch lock up converter in my 86 Grand National that was built to be locked up at full throttle.

[78 Chevyrado]

If you get a high stall TC make sure to get a big Tranny cooler if you drive it regularly. Slipping= heat It won't hurt it, just make it a lil hotter all the time under the stall speed.

[68Timber]

Do you know what cam is going in or the specs? I hate to hear that you don't know what you need, the cam will dictate exactly what stall speed you need. You can run up to a Comp 268 which is pretty healthy for a street driven truck with the stock converter. But 68 TT is spot on, if you put any converter in with a higher stall speed you will want to install an aftermarket tranny cooler in front of the radiator. It's not expensive, hard, or time-consuming, but it will dissipate the heat created by a higher stall convertor and keep that tranny running good.

You really need to know the cam specs first to know what convertor you need. The cam might really wake up your truck and turn it into a beast. But with a mismatched converter (too high stall speed) the truck will be a slug and you'll be disappointed.

[slugish]

Originally Posted by BRUISER

Do you know what cam is going in or the specs? I hate to hear that you don't know what you need, the cam will dictate exactly what stall speed you need. You can run up to a Comp 268 which is pretty healthy for a street driven truck with the stock converter. But 68 TT is spot on, if you put any converter in with a higher stall speed you will want to install an aftermarket tranny cooler in front of the radiator. It's not expensive, hard, or time-consuming, but it will dissipate the heat created by a higher stall convertor and keep that tranny running good.

You really need to know the cam specs first to know what convertor you need. The cam might really wake up your truck and turn it into a beast. But with a mismatched converter (too high stall speed) the truck will be a slug and you'll be disappointed.

What is the duration on a 268 cam -- Does it vary from manufactureer to another or is it standard-- the reason Iask Idont knowe what cam Ihave . but Ido know its got 224-230 duration with a 048 lift with 1.5 rockers. Its a comp. cam . My stall is shot , but tranny shifts fine . Iwould like to know what stall converter is best for me or do Ineed any at all . Iknow right now that Ican't get any rpms in my power band without the tires spinning with the shot converter Ihave

[78 Chevyrado]

Originally Posted by slugish

What is the duration on a 268 cam -- Does it vary from manufactureer to another or is it standard-- the reason Iask Idont knowe what cam Ihave . but Ido know its got 224-230 duration with a 048 lift with 1.5 rockers. Its a comp. cam . My stall is shot , but tranny shifts fine . Iwould like to know what stall converter is best for me or do Ineed any at all . Iknow right now that Ican't get any rpms in my power band without the tires spinning with the shot converter Ihave

What size engine?
What tranny?
What rear gear?
what diameter are the tires?
how much does the truck weigh?

[68Timber]

Originally Posted by slugish

What is the duration on a 268 cam -- Does it vary from manufactureer to another or is it standard-- the reason Iask Idont knowe what cam Ihave . but Ido know its got 224-230 duration with a 048 lift with 1.5 rockers. Its a comp. cam . My stall is shot , but tranny shifts fine . Iwould like to know what stall converter is best for me or do Ineed any at all . Iknow right now that Ican't get any rpms in my power band without the tires spinning with the shot converter Ihave

The durations and lift numbers on your cam are the same as the Comp 268, it may be what you have. You can use the stock converter with this cam, but it wouldn't hurt to put one slightly looser in, no more than 2200 rpm stall, and keep it a 12" converter.

[Chlsnk]

Originally Posted by BRUISER

The durations and lift numbers on your cam are the same as the Comp 268, it may be what you have. You can use the stock converter with this cam, but it wouldn't hurt to put one slightly looser in, no more than 2200 rpm stall, and keep it a 12" converter.

Why keep it 12" convertor what is the problem with the 11'' and 10'' ones I see for sale.

[qu1cks1lver56]

I've thought about putting a little higher stall converter on my truck just so I'm not fighting it with the brakes at a red light.

[Chlsnk]

http://www.starperf.com/index.php?p=...36017&parent=0 This is the cam going in my current engine build (358cid taken .40 over) I was told a 2200-2800 stall would be golden for me. Is this true?

[78 Chevyrado]

Originally Posted by qu1cks1lver56

I've thought about putting a little higher stall converter on my truck just so I'm not fighting it with the brakes at a red light.

A higher stall will cut the need for the "gas pedal two step". I had that in my mustang I used to have and I finally got a consevative 2500 stall and while it wasn't quite a big enough stall for that car, it did cut out playing with the gas at a redlight.

[qu1cks1lver56]

Originally Posted by 78 Chevyrado

A higher stall will cut the need for the "gas pedal two step". I had that in my mustang I used to have and I finally got a consevative 2500 stall and while it wasn't quite a big enough stall for that car, it did cut out playing with the gas at a redlight.

Yeah I have to do that sometimes, gets on my nerves. Some days it seems worse than others, I guess it's the goofy ass FL weather.

[78 Chevyrado]

Originally Posted by qu1cks1lver56

Yeah I have to do that sometimes, gets on my nerves. Some days it seems worse than others, I guess it's the goofy ass FL weather.

Yeah Luckily i didn't have to drive that thing in stop-n-go traffic much. I'd have done something about it if I would have had to. As much as I had to play with the pedal, I might as well have had a manual and just set the idle to whatever it needed to not stall out.

[3r!c84]

ok how do a lock up converter work?
and will it work with a higher stall tc?

[78 Chevyrado]

Originally Posted by 3r!c84

ok how do a lock up converter work?
and will it work with a higher stall tc?

a lockup converter will "lock up" at steady cruising speeds like on a highway. It has an actual clutch in the TC.

ALL automatic transmissions slip some at any and every speed, period. What the lockup converters to is make a physical lockup between the trans and engine, like a manual tranny. It's a gas mileage thing. It cut all slip out, but only under low load conditions.

If you ever drove something, say a 4 speed OD tranny, it will actually sound slike a 5 speed at times. You go through all 4 gears, and then the RPMS drop again when the TC locks up. OEM they are electronically controlled, but many aftermarket vendors make 700r4's and 4l60's that have a mechanical lockup, meaning it will work without electronics. I've never driven one with the mechanical setup but the electronis ones work well.

[qu1cks1lver56]

Originally Posted by 78 Chevyrado

a lockup converter will "lock up" at steady cruising speeds like on a highway. It has an actual clutch in the TC.

ALL automatic transmissions slip some at any and every speed, period. What the lockup converters to is make a physical lockup between the trans and engine, like a manual tranny. It's a gas mileage thing. It cut all slip out, but only under low load conditions.

If you ever drove something, say a 4 speed OD tranny, it will actually sound slike a 5 speed at times. You go through all 4 gears, and then the RPMS drop again when the TC locks up. OEM they are electronically controlled, but many aftermarket vendors make 700r4's and 4l60's that have a mechanical lockup, meaning it will work without electronics. I've never driven one with the mechanical setup but the electronis ones work well.

and the lockup makes better gas mileage? They make 'em for TH350's?

[78 Chevyrado]

Originally Posted by qu1cks1lver56

and the lockup makes better gas mileage? They make 'em for TH350's?

I don't think they make any for a TH350. It would either have to have electrical or mechanical provisions inside the trayys to operate.

[qu1cks1lver56]

Originally Posted by 78 Chevyrado

I don't think they make any for a TH350. It would either have to have electrical or mechanical provisions inside the trayys to operate.

There's never anything cool for a TH350

[piecesparts]

Originally Posted by 78 Chevyrado

I don't think they make any for a TH350. It would either have to have electrical or mechanical provisions inside the trayys to operate.

In the mid 80s, GM had a tranny called the 350C, that was a slightly different TH350 with a lock up converter. the trannys for the most part were good items, but the output shaft was smaller than a standard TH 350, so doing heavy duty rebuilds on them was not applicable.

As for a stall conveter, if you have a larger cam, the need for more idle speed to keep the engine running is necessary. That in itself, will put you upagainst the stall speed of a factory torque converter and you will sit at a stop trying to pull the truck through at just an idle. When you accelerate from this type of problem, the engine will try to stumble or bog, because you have not built any RPMs for the engine to work properly. The installation of a 2400 stall converter on my 700 R4 made a world of difference in my truck and it allows me to drive on the street in a more normal fashion, than before I installed it. It was worth the money and time.
If your cam is big enough, then you will need a stall to just make daily driving a joy and not a nuisance.