Just a quick question...

Was wondering about torque converter stall speeds. What are the advantages/disadvantages of different stall converters? And what does the number associated with the converter actually mean?

A true wasps nest iīd say.
The common meaning of stall speed is at what rev the motor will start pulling the rears around even if you apply the brakes as hard as you can muster.
Thing is that thereīs a LOT more to stall speed than that.
The converter mainly consists of the turbine,the driven wheel and the stator.
Now,by just altering converter diameter what i explained above can be altered-that is the rev where the engine pulls the rears no matter what.Just like the idea behind a stick flywheel in a sense.
Stallspeed can also be altered by altering the angle of the fins that transmits the torq of the motor from the turbine to the driven wheel within the converter.
But....
The real joker in the deck is by all means the stator.This is a nifty little "wheel" that fits in the inner diamter of the two others,and itīs only task in life is to direct the oil going into the driven wheel.
By doing so it will alter the multiplication of the converter.
This stator is also equipped with a one way "lock".
Now what happens is that the stator will not have the same speed as the driven wheel at first,they will play catch up with each other and thatīs what is used to alter the mulitplication factor of the converter.
Without going into converter or stator design,let it suffice to say that by altering the stators physical apperance you can get VERY varying behavior from it.
The one way "lock"-or sprag as itīs called-will guarantee that it ONLY works the catch up game at acceleration and not when for instance engine braking.
Sprags have been known to collapse however,so thatīs ALSO an area that is adressed in a hi-po stator.

Then whatīs the point of a converter with higher stall?
Basically itīs to let the engine get closer to itīs torq peak at launch-Ie;to let the motor in case make more power.

Now..the nomer stall speed per se-as itīs usually referenced-isnīt by far as important as something called flash stallspeed.
The latter is what the racer is concerned with.The latter is also normally numerically higher then the more common nomer stall.

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DVC-2000.Racing
482 cubes of fogger injected thunder in a 71 z.
racing@mbox303.swipnet.se (http://racing@mbox303.swipnet.se)

Hey racing, Very well put. I've read alot about converters, (still doesn't mean I know alot about them) and I think your explanation was pretty good. Thanks.

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Steve
67 SS 396,4-sp
67 RS 327,4-sp
72 RS 350/350
69 4X4 suburban 350,4-sp
73 3/4 ton 454/400
http://www.geocities.com/stevocamaro

Thanks a lot racing. I've got a picture in my head now how they work and what the #'s mean.

I must say Racing, I love these detailed explanations!!! The only thing I might add is that normally would would want a converter that has a stall speed high enough to get you into the initial power band range of your cam. So for a cam with a power range of say 2500-5500, you would want a convertor stall speed in the 2400-2600 RPM range ASSUMING you are running a street/strip daily driver type of car.

What say you, racing??? DO you concurr or do you wish to expound on this???

Nahh,i agree with ya alright.
<BLOCKQUOTE>quote:</font><HR>Basically itīs to let the engine get closer to itīs torq peak at launch-Ie;to let the motor in case make more power<HR></BLOCKQUOTE>

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DVC-2000.Racing
482 cubes of fogger injected thunder in a 71 z.
racing@mbox303.swipnet.se (http://racing@mbox303.swipnet.se)

Hey Racing, Is it Ok to buy a "Generic" Name brand stall converter, or pay BIG bucks for a custom converter with the same stall speeds?

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Have you checked your SS's lately

A hard one man..
You normally get what you pay for IMO.
Now iīm not talking the over the counter B&M stuff here,but more down to the ground race parts.
On the other end of the spectre thereīs converters like the bosshog and such.
The latter has worked fine up until about 400 ponies for me one more than one occasion,but that seems to be the limit.
Race conerters are not for the street IMO however.
Another thing you absolutely MUST remember when installing a high staller is to add a cooler.They all produce more heat.


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DVC-2000.Racing
482 cubes of fogger injected thunder in a 71 z.
racing@mbox303.swipnet.se (http://racing@mbox303.swipnet.se)

SS,

I've tried alot of them and Hughes seems to me to work well and it's less expensive than most. Here I am referring to converters in the 2400-2600 stall speed range. I don't mess with the 3000-4500 stall speed convertors at all so I can't say there.

A car guru friend of mine told me that All converters are numbered for big blocks,. so that if I purchased a 3000 stall for my smallblock with a Pwrglide, or Th350 for ex: then my stall speed would actually be about 200 to 300 less rpm than listed since it was a small block. is this true? if so it might be somthing to look out for?

I was interested in doing "somthing" with my camaro, I was going to do a crate motor for now untill I can get the 327 totally redone. but I wanted a larger cam in the 327, somthing with like a 2500-6000 range. so my converter should be about 2500-3000 right?

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Chris's 67 RS can be seen at http://www.geocities.com/macphreak4evr/index.html
JOIN THE CAMARO NET WEBRING! www.geocities.com/macphreak4evr/webring/webringjoin.htm (http://www.geocities.com/macphreak4evr/webring/webringjoin.htm) !!!

[This message has been edited by Chris Edwards (edited 05-01-2000).]

Chris,

I wouldn't go over 2,400 stall on a street car especially if you do any highway driving. The additonal slippage at 3000 and up stall can create some unwanted heat in a dialy driver type of car. It is also a good idea to run a trans cooler.