boese1978

Can you guys tell me what a stall converter does exactly? I guess what I mean is what would I feel or notice in difference when driving compared to stock? What do the stall speeds mean? any information would be helpful.....plain english also would be appreciated!! I can tell you how an internal combustion engine works but damned if I know enough about transmissions!
Thanks!

455man

It's basically like popping the clutch on a stick. The stall converter slips until a certain RPM then locks up and launches your car. Adding a higher stall converter would launch you harder from a stop or spin the tires more. Might feel a little in the shifts.

boese1978

Does that mean there is a bit of lag ....I mean when you step on the gas do the rpm's go up a bit and then launch the car?

455man

Well it depends on how high the stall is. if you have a 2500 stall the car will want to roll forward like it does now but will reach higher rpms before locking up. Most stock converters are around 1800 rpm.

droptopron

A higher stall speed isn't exactly like popping a clutch. A trans brake would give you that effect. A higher stall speed means just that. The transmission will slip until the engine reaches that RPM. The idea is to have the car launch in your cam power band. Also, note that converters are usually sold referred to as 10"/11"...The smaller the diameter the higher the stall but they usually will give you an RPM range. The actuall stall will difffer based on your engine output and other factors. If you call the manufacture with the specifics of your set up (not guesstimates) they can give you more insight. If you have a stock cam or close to stock you don't want a very high stall speed. As far as drivability your car will have a higher stall so it will slip around town when leaving stops and in slow traffic. An external cooler is always a good investment but more so with an increased stall speed.

boese1978

so with all this extra slipping around town, does that wear out the transmission sooner? when driving around town, stop and go, does it actually feel like the trans is slipping? My goal is to have a torque heavy, off the line street machine. Not at all interested in top end speed. Do I need or "want" a stall converter?
Appreciate the education.

gearheads78

Your combination will tell you if you need one and what you need. If you have a big enough cam the car will not even idle in gear without a higher stall converter.

droptopron

It will slip so it will generate more heat. Did you pick a cam yet? The convertor should match the power band of your cam profile.

boese1978

I have not picked a cam yet. I am educating myself ( with all of you guys assisting) before I start buying parts. Still wondering if this slipping and heat ( I plan on adding a cooler) will take some life from the tran. How does it affect driveability?

droptopron

It will slip at around town speeds.

boese1978

"It will slip at around town speeds"

Hearing that makes me think, forget a stall converter.....what are the advantages? My plan is to get a bit more agrerssive cam than stock.....

droptopron

A stock convertor should stall around 1,400 IIRC (correct me if I am wrong guys) so if you don't want to run a higher stall speed you should look for a cam that has a power band that starts around there. More or less a cam that would be good with a Performer should be good with a stock convertor. As an in between choice there are convertors like the TCI Saturday Night Special that is a touch more agressive than a stock (a few huindred RPM) but lower than an Street/Strip convertor.

gearheads78

You need to decide what you want out of the car and the power range you want to make power. You select the cam and converter to match the combo. Don't worry about trans life. Just run a good cooler and don't cheap out on the converter. A good quality converter will drive around town fine and still flash what it needs to when you put the hammer down. Not quite the same situation as an Olds motor (I shifted a 7300 rpm) but the last fast street car I built was a 98 TA 347ci LS1 with a 4500 converter and a TH400. Car would cruise around town great and cut 1.52-1.55 60ft times at the track on small drag radials. Its all about combination.

coppercutlass

I ran bigger cam in my 350 and with a tci satursay nigh special 2000-2200 rpm stall it would lunge a little in drive and it would not spin the tires very well but it was what i had from my previous combo the funds did not allow for a new converter . I added a higher stall converter this winter 2600-2800 but closer to 3000 rpm and it lights the tires up from a 15-20 mph roll now. It was a major improvement for me. I ran the tci with no cooler and no issues i just used the stock cooler built intot he radiator and it was good. I know it was mentioned if there is some for of lag . Well the kinda is if you are cruising lets say 35 mph at low rpms then you floor it the engine will rev untill the converter locks up but that makes for some fun on the street its not a major lag like a bog but the engine will rev a bit before the converter locks up from my experience .

DeltaPace77

With all the information given, suprised there's no mention that the torque coverter actually multiplies engine torque at launch. Original Hydromatics had 4 speeds, with only a fluid coupling clutch with no torque multiplication. When later Turbo Hydromatics came out with tourque mutiplying converters, the lower 1st gear was dropped, as was deemed uneeded. Stall speed can be a tricky number, as is loosely defined as the engine rpm of a 350 cu in engine floored while holding the brakes. Will be a higher rpm against a torquier 455, and also varries by manufacturer. There's a lot more to this, but from experience, wouldn't go much higher stall from stock on the street, especially if running running a tall(2.56) axle, or you'll be sorry. You may get a bit more launch floored from a light, but can feel very slushy, unresponsive around town, with lots of slip. This post is getting pretty long, and others will surely chime in with more.

66-3X2 442

Torque convertor stall is one of the biggest myths there is. Every torque convertor will 'flash' different behind different engines. The way you check stall or the is flash is,get the car moving about 25 -30 mph in high gear. Then you hit the throttle and watch the tach and whatever RPM it flashes to is the stall speed. I've heard guys say to put your foot on the brake and hit the throttle and watch the tach,wrong. You can take a loose convertor from behind a small block and put it in a big block and the stall will change. Like previously posted,the convertor is a torque multiplier. The convertor will tighten up behind an engine with more torque like a big block than a less torque small block. If you using a 400 turbo,one trick is to use a 350 turbo convertor which is smaller in diameter to gain more stall. The smaller the convertor the more stall that is available. Some racing convertors are as small as 7" in diameter. You can call the top convertor vendors and I mean top not just a name brand either to order a convertor. You will have to give them a lot of info about your combination to get the correct convertor. Be leary of off the shelf or 'we have it in stock' vendors because you will get a generic convertor that they think will work. Will an off the shelf convertor be better than stock?you betcha it will but to get the maximum convertor,it will need to be custom made. Custom built convertors are more pricey than off the shelf generic convertors but IMHO,it's the best money you can spend on your car for performance gain. Check out PTC here in Alabama,they build a great product and are great guys to deal with. Click here http://ptcrace.com/

jag1886

I put a 2000 stall converter in my car and you can't tell much difference just normal driving around, but put a little brake on at a light and the converter will let the engine rev up higher before engaging. The advantage of a converter with more stall is to let the engine rev up into the cams power range before the launch. If you don't match the cam and the converter you will have a slug coming off the line. My converter goes into lock up 500 RPM's above where the cam and intake start to work.

charlierogers

this is all the info you need right here! if you cannot afford a good converter wait till you can. off the shelf/ cheap converters are more often than not time bombs waiting to come apart and send metal through the trans. now you have the price of a new/rebuilt trans+ a new converter. the upside too a custom converter is a happy trans and great performance!

TripDeuces

Flash Stall can be determined a couple of different ways:
With the vehicle sitting still and idling in low gear, apply full throttle. As the vehicle begins its motion forward, notice the RPM hand on the tachometer. That is your Flash Stall. (Engine should be very responsive from idle. If not, camshaft timing and/or carburetor adjustments may need to be made in order for engine to be crisp from idle.) With the vehicle in forward motion in high or drive gear and at its lowest mph where it will not kick back to a lower gear, apply full throttle while noticing rpm hand of tachometer. (This measurement of flash stall is best achieved with a full manual transmission.)

Direct from TCI. Sorry about the size.

66-3X2 442

This is one of the vendors I'm talking about. I have several NHRA/IHRA/NMCA National Records hanging on the wall and I've made a pass or two down the dragstrip. I guarantee you that you can call TCI and they have one ready to go,seen it too many times. I'm not saying they don't build good convertors but there's better vendors to buy from. I used A-1 Automatic trans & convertors for many years and the owner Marv Ripes always told me the high gear method was the correct way to determine stall/flash.

droptopron

Not to hijack but what about anti-ballooning plates? When do you say they are needed?

gearheads78

Anytime you will use a transbrake or nitrous for sure. Most good converters will already have them.

coppercutlass

Oddly my cheap ebay converter has it. I dunno if it's cheap but it was built by a trans shop in the east coast I think called winners choice transmissions . So far it seems to be working fine a little looser but not by much might be my combo too.

66-3X2 442

This is true,street cars really don't have a need for anti balloon plates. In a drag car coming out of the burn out box,the car needs to come to a complete rest and not keep the throttle wide open till the tires catch up. That is a convertor killer for sure.