Torque Convertor Stall Question
Thread Starter
Instructor
Joined: Oct 2007
Posts: 154
Likes: 1
From: Hanover Maryland
Torque Convertor Stall Question
I am looking into swapping my th350 trans to a 2004r and questioning what stall convertor to put in? My motor is being built now and will be a stroked 350 making around 450hp.
So the biggest debate comes with who you talk to (newer motor guys vs. old school guys)
The newer guys all say to run a high stall. They say a minimum of 3000 stall where as the old school guys are saying to run a max of 3000. My brother is running a 3600 in his street driven 95 trans am.
I don't fully understand what the different stalls are doing for me so any help or input is appreciated
So the biggest debate comes with who you talk to (newer motor guys vs. old school guys)
The newer guys all say to run a high stall. They say a minimum of 3000 stall where as the old school guys are saying to run a max of 3000. My brother is running a 3600 in his street driven 95 trans am.
I don't fully understand what the different stalls are doing for me so any help or input is appreciated
Safety Car
Joined: Jan 2009
Posts: 3,736
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From: anchorage ak
A stall converter will allow more engine slipage to achieve the desired rpm range. You should want to have the stall at 2 to 300 rpm higher then were your engine starts to make decent power, or at least thats my thoughts on it. There is no one size fits all when it comes to torque converters, to low and the engine will feel doggy, to high and you cheat your self out of torque. If yo7r running a lock up, you can get away with a higher stall to match the rpmrange of the cam, with out slipage at cruize rpms.
Team Owner
Joined: Jan 2006
Posts: 37,637
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From: Crossville TN
Select the manufacturer (brand) of converter that you want to use. Then, call the technical support folks for that manufacturer. Tell them you want to buy your converter from them but need help on making the correct choice.
They will ask you questions about your car (engine, upgrades, rear gear, transmission, tires) and also about what you want to do with the car. You need to be honest about your expectations for the car.
They will suggest some alternative units along with the pros and cons of each one. You can make the choice from there.
Anyone who goes about selecting a converter by any other method is either an automotive genius, very gullible, or just a fool. Just trying to tell you straight....
They will ask you questions about your car (engine, upgrades, rear gear, transmission, tires) and also about what you want to do with the car. You need to be honest about your expectations for the car.
They will suggest some alternative units along with the pros and cons of each one. You can make the choice from there.
Anyone who goes about selecting a converter by any other method is either an automotive genius, very gullible, or just a fool. Just trying to tell you straight....
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
That's true...for those that don't know any better. There is quite a lot involved with correctly selecting the right converter. Heck, you can stick anything in there and it will work--just not very well.
Thread Starter
Instructor
Joined: Oct 2007
Posts: 154
Likes: 1
From: Hanover Maryland
I guess my best bet will be to get all my motor specs from my engine builder then call the torque convertor company and ask them like you said.
It just seems there are a lot of different opinions on the matter. I have found that the newer cars and motor builders all prefer the high stall convertors even for stock motors like the LT and LS engines.
Yet if you talk to older guys building Gen1 small block they all say lower torque convertors.
I was just trying to figure out if it is preference or something with the newer electronic stuff that likes a higher stall.
I have heard that some people prefer to even drive a high 3600 stall car better then a manual trans.
It just seems there are a lot of different opinions on the matter. I have found that the newer cars and motor builders all prefer the high stall convertors even for stock motors like the LT and LS engines.
Yet if you talk to older guys building Gen1 small block they all say lower torque convertors.
I was just trying to figure out if it is preference or something with the newer electronic stuff that likes a higher stall.
I have heard that some people prefer to even drive a high 3600 stall car better then a manual trans.
Safety Car
Joined: Jan 2009
Posts: 3,736
Likes: 56
From: anchorage ak
True but even cam manufacturers recomend stall speed, but i ran the 262 in the l48 with 3.08 gears, i put a 2400 rpm stall converter in and it made the car so much more fun to drive, now comp said that it would be fine with out a stall converter, ofcourse there in the business of selling cams and the added expense of a stall converter might make one not want to change the cam, but if i were recomending the 262 with 3.08 gears id recomend the 2400 rpm stall. Maybe i got lucky. I prefer to use a stall converter matched to the rpm range of the engine.
Last edited by bluedawg; Feb 7, 2013 at 02:46 AM.
Instructor
Joined: Jan 2013
Posts: 167
Likes: 0
From: Battle Creek MI
if you really want to muddy the waters a little bit more regarding converter selection, do some research into STR... Stall Torque Ratio.
You will find some converters actually multiply torque better than others.
You will find some converters actually multiply torque better than others.
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Safety Car
Joined: Jan 2009
Posts: 4,000
Likes: 299
From: New York
Just remember TO much stall is not good. If you looking for a nice daily driver I would keep the speed 2400 or so , 3k or more will not be fun unless you plan on racing or have a cam that will not run with out a very high idle With 450 hp I doubt you will have idle issues.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Everyone has their "beliefs" and "opinions" on this issue. But, very few have any data or proper method to support them. A mechanic who works on drag race vehicles might know some stuff about what works for drag racing; but he knows nothing of normal driving needs. And, vice versa.
T/C manufacturing techs have been trained on how to assess your vehicle's needs...based on the info you provide to their questions...and how to factor-in the performance of your engine, etc. to help you get the BEST converter match for your car.
You can either do that, or you can "guess". Take your pick. [Oh. If you just listen to someone else who professes to know what they're doing....then you fall into the 'fool' category.]
T/C manufacturing techs have been trained on how to assess your vehicle's needs...based on the info you provide to their questions...and how to factor-in the performance of your engine, etc. to help you get the BEST converter match for your car.
You can either do that, or you can "guess". Take your pick. [Oh. If you just listen to someone else who professes to know what they're doing....then you fall into the 'fool' category.]
Instructor
Joined: Jan 2013
Posts: 167
Likes: 0
From: Battle Creek MI
Everyone has their "beliefs" and "opinions" on this issue. But, very few have any data or proper method to support them. A mechanic who works on drag race vehicles might know some stuff about what works for drag racing; but he knows nothing of normal driving needs. And, vice versa.
T/C manufacturing techs have been trained on how to assess your vehicle's needs...based on the info you provide to their questions...and how to factor-in the performance of your engine, etc. to help you get the BEST converter match for your car.
You can either do that, or you can "guess". Take your pick. [Oh. If you just listen to someone else who professes to know what they're doing....then you fall into the 'fool' category.]
T/C manufacturing techs have been trained on how to assess your vehicle's needs...based on the info you provide to their questions...and how to factor-in the performance of your engine, etc. to help you get the BEST converter match for your car.
You can either do that, or you can "guess". Take your pick. [Oh. If you just listen to someone else who professes to know what they're doing....then you fall into the 'fool' category.]
I'd recommend everyone read this quick little blurb from wikipedia about torque multiplication. I'd also advise you ask each tech about the specific STR for their recommended converter. If one of them tells you it's not important, move on.
http://en.wikipedia.org/wiki/Torque_...multiplication
Drifting
Joined: Dec 2004
Posts: 1,714
Likes: 42
From: Austin Texas
What are your rear gears?
I had a th400 and bought a 2800 converter from ptcrace.com Then, like you, I swapped to a 200-4R with a D5 stock converter.
I sold my th400 and get this, PTC will give me store credit for the purchase price of my original converter. They have a program for it, it' s called Customer Service!
Get your cam card and give them a call. I plan to get a lock up from them. My car locks automatically in 4th so I will not be able to WOT to 4th but that is not an issue for me. I also plan to get a switch to be able to lock third when cruising.
I had a th400 and bought a 2800 converter from ptcrace.com Then, like you, I swapped to a 200-4R with a D5 stock converter.
I sold my th400 and get this, PTC will give me store credit for the purchase price of my original converter. They have a program for it, it' s called Customer Service!
Get your cam card and give them a call. I plan to get a lock up from them. My car locks automatically in 4th so I will not be able to WOT to 4th but that is not an issue for me. I also plan to get a switch to be able to lock third when cruising.
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
Other factors to consider other than stall rpm (Brake stall) is, like timberwolf mentioned torque multiplication.
At 450hp you'll want to consider a balloon plate as well.
Percent of slippage can be important for limiting heat build up while not in lock up mode and I would install an additional fluid cooler to keep trannie at a low temp it will be happier and last longer.
A reinforced sprag or spragless converter should be used as well.
Don't be tempted by the cheap summit racing or similar converters, the price is attractive but you'll pay plenty if the thing frags and sends all the little pieces through your transmission.
Do your homework and you'll not have to worry about it later on.
At 450hp you'll want to consider a balloon plate as well.
Percent of slippage can be important for limiting heat build up while not in lock up mode and I would install an additional fluid cooler to keep trannie at a low temp it will be happier and last longer.
A reinforced sprag or spragless converter should be used as well.
Don't be tempted by the cheap summit racing or similar converters, the price is attractive but you'll pay plenty if the thing frags and sends all the little pieces through your transmission.
Do your homework and you'll not have to worry about it later on.
Safety Car
Joined: Jan 2009
Posts: 4,000
Likes: 299
From: New York
You do NOT need match converter to cam profiles, tire size, gears , potential et times and the like , you need a converter that allows a good idle ability , holding on light inclines and an occasional full power take off to remind your self why you have a Corvette. You have a nicely powered car , not a road racer or a drag car looking for its best ET.
Can you get scientific , Of course , can you get a full blown race converter dialed in to max et times sure .. But be practical and get a converter with a moderate stall higher then stock but not so high that every time you pull away from a stand still it sounds like your slipping a clutch as the engine RPM rises to get the car moving.
I use to run and operate a transmission company 3 locations , can converter choices make a difference of course , but keep your eye on the ball and do get crazy about it or make it this battle as so many love to do " I know more then you read this" ,, bla bla bla .. Summit Jegs and a number of other places and I mean a big number of other places can offer you what your looking for and not break the bank.
Can you get scientific , Of course , can you get a full blown race converter dialed in to max et times sure .. But be practical and get a converter with a moderate stall higher then stock but not so high that every time you pull away from a stand still it sounds like your slipping a clutch as the engine RPM rises to get the car moving.
I use to run and operate a transmission company 3 locations , can converter choices make a difference of course , but keep your eye on the ball and do get crazy about it or make it this battle as so many love to do " I know more then you read this" ,, bla bla bla .. Summit Jegs and a number of other places and I mean a big number of other places can offer you what your looking for and not break the bank.
Melting Slicks
Joined: Dec 2009
Posts: 3,233
Likes: 657
From: Thunder Bay
I am on my third torque converter. First was 1800 stall with the T350 trans. That was upgraded to 2200 stall with the T350 trans and a shift kit. Much better. When I put the 700R4 in, I used a B&M 2500 stall converterwith lock up. Not sure I would use that much stall speed with an non locking converter. My engine is a 383 with 224 deg. of intake duration, so its not that wild. In my opinion,for what its worth, the higher stall is a definite improvement.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
All of these "theories" just proves that you need to call a qualified tech support person (or several makers, if you wish), so that you have some GOOD information [rather than personal preferences] with which to make your decision.
Burning Brakes
Joined: Jan 2007
Posts: 1,057
Likes: 4
From: Concord Calif
What 7T1vette says is some of the best advise you are getting here. Most have no clue how a converter even works, there is much much more to consider than stahl speed, such things as converter size as gets involved as well as others, so call a top company and go that route for the best options on a converter. But then do what you want as it is your car.
Thread Starter
Instructor
Joined: Oct 2007
Posts: 154
Likes: 1
From: Hanover Maryland
Thanks to everyone for the help. Looks like I'll be calling a couple convertor places and asking them what I should run. Hopefully I dont get much of a difference between there recommendations
Safety Car
Joined: Jan 2009
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From: anchorage ak
What cam shaft are you running? Were do you expect your engine to start making power, dyno numbers work, combination expectations work, im not saying don't call tci or hughes, but out of curiosity, since im such a fool or idiot, were will your combination start to make power, what does the cam manufactuer say, post them first, and then what do the stall converter companies say? Humor us.
Last edited by bluedawg; Feb 8, 2013 at 12:44 AM.